Child Development Glossary

A plan providing accommodations for students with disabilities that affect learning, under Section 504 of the Rehabilitation Act. Less formal than an IEP but legally binding. Common for ADHD, chronic health conditions, and learning differences.

Changes to how a student accesses learning without altering what is taught. Examples include extended time, preferential seating, breaks, and technology aids. Differ from modifications, which change the content or expectations.

Potentially traumatic events occurring before age 18, including abuse, neglect, and household dysfunction. ACEs have a dose-response relationship with adult health problems. Protective factors (caring adults, community support) can buffer their effects.

Also known as: retrieval practice

A learning strategy where you actively try to remember information rather than passively reviewing it. Testing yourself, even if you get answers wrong, strengthens memory more than re-reading or highlighting. It's effortful but highly effective.

Also known as: Attention-Deficit/Hyperactivity Disorder, ADD

Attention-Deficit/Hyperactivity Disorder, a neurodevelopmental condition characterized by difficulty with attention, hyperactivity, and impulsivity. Affects 5-7% of children. A brain-based condition, not lack of willpower. Treatment includes behavioral strategies and sometimes medication.

The age at which a child's score would be average. A 4-year-old performing like an average 3-year-old has an age equivalent of 3 years. Can be misleading and is generally less preferred than percentiles or standard scores.

Behavior intended to harm others physically or psychologically. Physical aggression peaks around age 2-3 and normally declines as language and emotional regulation develop. Persistent aggression may indicate need for intervention. Includes relational aggression (social exclusion, rumor-spreading).

The protective fluid surrounding the fetus in the uterus. It cushions the baby, maintains temperature, allows movement for muscle development, and contains substances that indicate fetal health. Too much or too little can indicate problems.

The brain's emotional processing center, responsible for detecting threats and triggering the fight-or-flight response. In children, the amygdala develops before the prefrontal cortex, which is why emotional reactions often precede rational thinking, especially under stress.

Natural compounds in foods that can interfere with nutrient absorption. Examples include phytates in grains and legumes (bind minerals), oxalates in spinach (bind calcium), and lectins in raw legumes. Proper preparation (soaking, cooking) reduces anti-nutrients.

Compounds that protect cells from damage by neutralizing free radicals. Include vitamins C and E, beta-carotene, and polyphenols. Found in colorful fruits and vegetables. Support immune function and may protect brain health.

A group of conditions involving excessive fear or worry that interferes with daily functioning. Common types in children include separation anxiety, generalized anxiety, social anxiety, and specific phobias. Highly treatable with therapy and sometimes medication.

A quick assessment of newborn health at 1 and 5 minutes after birth, scoring appearance (color), pulse, grimace (reflexes), activity (muscle tone), and respiration. Scores range from 0-10, with 7+ considered normal. Used to guide immediate care needs.

Also known as: ABA

A therapy approach using principles of learning to increase helpful behaviors and decrease harmful ones. Common for autism treatment. Controversial when overly focused on compliance; best practices emphasize naturalistic, child-led approaches.

Using artistic creation as a therapeutic tool for expression, processing, and healing. Children may find it easier to express through art than words. Effective for trauma, anxiety, and various emotional challenges. Conducted by trained art therapists.

The physical production of speech sounds using the tongue, lips, teeth, and palate. Children gradually master all speech sounds, with some (like 'r' and 'th') not fully acquired until age 7-8. Articulation disorders involve difficulty producing sounds correctly.

Also known as: Ages and Stages Questionnaire

Ages and Stages Questionnaire, a widely used parent-completed developmental screening tool. Covers communication, gross motor, fine motor, problem-solving, and personal-social domains. Takes about 15 minutes to complete.

The emotional bond between a child and caregiver that develops in the first years of life. Secure attachment, formed through consistent, responsive caregiving, provides a foundation for healthy social-emotional development, self-esteem, and future relationships.

The length of time a person can concentrate on a task or stimulus without becoming distracted. Attention span naturally increases with age—roughly 2-3 minutes per year of age for focused tasks. It's affected by interest, sleep, screen habits, and environment.

Also known as: ASD, autism

A neurodevelopmental condition affecting social communication and involving restricted/repetitive behaviors. Spectrum ranges from significant support needs to highly independent. Early intervention improves outcomes. Affects about 1 in 36 children.

The ability to make one's own decisions and govern oneself. Autonomy development is a key task from toddlerhood ('I do it myself!') through adolescence. Parents gradually shift from control to monitoring to letting go as autonomy grows.

A group of water-soluble vitamins essential for brain function, energy production, and nervous system health. Key B vitamins for children include B12 (nerve function), folate (cell division), B6 (neurotransmitter production), and thiamine (energy metabolism).

Repetitive syllable sounds (like 'ba-ba' or 'da-da') that infants produce starting around 6 months. Babbling is universal across languages and cultures and represents an important step in speech development. It becomes more speech-like over time.

A protein that supports neuron survival, growth, and the formation of new neural connections. Often called 'fertilizer for the brain,' BDNF levels are increased by exercise, learning, and omega-3 fatty acids, and decreased by chronic stress and poor sleep.

Refusal or difficulty settling for bed, common in toddlers and preschoolers. Causes include insufficient sleep pressure, poor sleep associations, anxiety, or need for connection. Consistent routines and boundaries help.

A child-friendly term for intense feelings that feel overwhelming. Helping children understand that all emotions are valid (though all behaviors aren't) builds emotional intelligence. The goal isn't to eliminate big emotions but to learn to manage them.

The ability to use both sides of the body together in a coordinated way. It's essential for activities like cutting (one hand holds paper, other cuts), riding a bike, and catching a ball. It develops throughout early childhood and requires practice.

The ability to use two languages. Contrary to old myths, bilingualism doesn't cause language delays or confusion—it enhances cognitive flexibility and executive function. Children can learn multiple languages simultaneously from birth or sequentially.

Using technology to provide real-time information about physiological processes (heart rate, muscle tension, breathing) to help develop self-regulation skills. Used for anxiety, ADHD, and chronic conditions. Child-friendly versions often use games.

The body's ability to maintain stable glucose levels. Children are particularly sensitive to blood sugar fluctuations, which affect mood, behavior, attention, and energy. Balanced meals with protein, fat, and fiber help stabilize blood sugar.

Also known as: BBB

A selective barrier between blood and brain that protects the brain from many substances while allowing essential nutrients through. Not fully developed at birth, making infants more vulnerable to environmental toxins.

High-energy visible light (400-500nm) emitted by screens, LED lights, and the sun. Evening blue light exposure suppresses melatonin and disrupts circadian rhythms. May also contribute to digital eye strain. Blue light blocking glasses and screen filters can help.

The intense attachment that develops between parents and their baby. While attachment builds over time, early bonding is supported by skin-to-skin contact, eye contact, and responsive care. Hormones like oxytocin facilitate bonding.

A chemical used in plastics and can linings that acts as an endocrine disruptor, mimicking estrogen. Linked to behavioral problems, early puberty, and metabolic issues. 'BPA-free' products may contain similar chemicals (BPS, BPF) with similar concerns.

The oldest part of the brain, controlling vital functions like breathing, heart rate, and sleep-wake cycles. Fully functional at birth and serves as the foundation for higher brain development.

Feeding an infant breast milk directly from the breast. Provides optimal nutrition, immune protection, and bonding. WHO recommends exclusive breastfeeding for 6 months, then continued breastfeeding with complementary foods for 2 years or beyond.

Repeated aggressive behavior with power imbalance, including physical, verbal, social, and cyber bullying. Affects roughly 20% of students. Harmful to both victims and perpetrators. Prevention involves whole-school approaches, bystander intervention, and social-emotional learning.

The brain region primarily responsible for motor control, coordination, and balance, but also involved in cognitive functions like attention and language. The cerebellum contains more neurons than the rest of the brain combined and develops rapidly in the first few years of life.

Also known as: CP

A group of disorders affecting movement and posture, caused by damage to the developing brain before, during, or shortly after birth. Ranges from mild to severe. Not progressive but lifelong. Physical therapy, occupational therapy, and sometimes surgery help.

Also known as: C-section, cesarean delivery

Surgical delivery of a baby through incisions in the abdomen and uterus. May be planned or emergency. While sometimes necessary, vaginal birth when possible provides beneficial microbiome exposure. Recovery takes longer than vaginal delivery.

An essential nutrient crucial for brain development, particularly memory and attention centers. Choline requirements are highest during pregnancy and early childhood. Found in eggs (especially yolks), liver, and meat. Many children don't get adequate choline.

An individual's natural tendency toward being a morning person ('lark') or evening person ('owl'). Chronotype has a genetic component and shifts during adolescence toward later preferences, then gradually shifts earlier in adulthood.

The internal 24-hour biological clock that regulates sleep-wake cycles, hormone release, body temperature, and other bodily functions. In children, circadian rhythms are still developing and can be disrupted by irregular schedules, light exposure, and screen time before bed.

The EWG's annual list of 15 produce items with the lowest pesticide residues, where conventional (non-organic) is considered acceptable. Typically includes avocados, sweet corn, and pineapple. Helps prioritize organic purchases for budget-conscious families.

The process by which caregivers help children manage their emotions and stress responses through warm, responsive interactions. Before children can self-regulate, they need adults to co-regulate with them. It involves the caregiver staying calm and providing comfort during distress.

Watching screen content together with a child and discussing it. Co-viewing significantly improves educational outcomes from media by helping children understand content, make connections, and apply learning. It transforms passive viewing into active learning.

Alternating between two or more languages within a conversation or sentence. Common among bilingual speakers, it's not a sign of confusion but of linguistic skill—speakers switch based on context, topic, or to express nuance.

Also known as: CBT

A therapy approach focusing on the connection between thoughts, feelings, and behaviors. Adapted for children, CBT is effective for anxiety, depression, and behavioral problems. Teaches skills for challenging unhelpful thoughts and developing coping strategies.

Also known as: mental flexibility, set shifting

The ability to switch between thinking about different concepts, adapt to new rules, or see things from different perspectives. It enables creative problem-solving and adapting to change. Also called 'mental flexibility' or 'set shifting.'

The first milk produced by the breast, available from late pregnancy through the first few days after birth. It's concentrated with antibodies, immune factors, and nutrients. Often called 'liquid gold' for its yellowish color and high value for newborn immunity.

A more serious behavior disorder involving violation of rules and others' rights (aggression, destruction, theft, deceit). Risk factor for later antisocial behavior. Requires comprehensive treatment including family intervention.

The ability to resolve disagreements peacefully. Children learn through modeling and coaching to use words, compromise, take turns, and find win-win solutions. These skills transfer from family to peer relationships and later to adult interactions.

Changing behavior or beliefs to match those of a group. A normal social process that increases in adolescence. Balance between conformity (belonging) and individuality (authenticity) is part of identity development.

The internal sense of right and wrong that guides behavior. Develops through the internalization of family and cultural values during childhood. A healthy conscience allows children to regulate behavior even when no one is watching.

Soft vowel sounds ('oo' and 'ah') that babies make starting around 2-3 months. One of the first vocalizations beyond crying, cooing is an early form of communication and social interaction. Parents naturally respond, creating 'conversations.'

Play involving shared goals and coordinated activity between children, typically emerging around age 3-4. Children assign roles, follow rules, and work together toward common purposes. Requires and develops social skills like negotiation and perspective-taking.

The bundle of nerve fibers connecting the brain's left and right hemispheres, enabling communication between them. It develops throughout childhood and is essential for tasks requiring both hemispheres, like language, spatial reasoning, and complex motor skills.

Also known as: cerebral cortex

The brain's outer layer, responsible for higher cognitive functions including thought, language, and consciousness. Different regions specialize in different functions. The cortex is the last brain region to fully mature, continuing development into the mid-20s.

The body's primary stress hormone, released by the adrenal glands. Acute cortisol helps with alertness and stress response, but chronic elevation damages the hippocampus and impairs memory, learning, and emotional regulation.

Assessment measuring a child's performance against specific criteria or standards rather than peer comparison. Shows what skills a child has mastered and what comes next. More useful for instructional planning.

Also known as: critical windows, developmental windows

Specific time windows during development when the brain is particularly sensitive to certain types of environmental input. During these periods, specific experiences are required for normal development. Examples include language acquisition (birth to age 7) and visual development (first few months of life).

The ability to reach across the body's invisible center line to perform tasks on the opposite side. It requires coordination between brain hemispheres and is important for writing, reading, and many daily activities. Difficulty crossing midline can affect academics.

Accumulated knowledge and skills acquired through learning and experience, including vocabulary, facts, and expertise. Unlike fluid intelligence, crystallized intelligence continues to grow throughout life with continued learning.

The ability to translate written words into speech sounds using letter-sound knowledge. A fundamental reading skill that must become automatic (fluent) for comprehension to occur. Taught through systematic phonics instruction.

Also known as: slow-wave sleep, N3 sleep, delta sleep

The most restorative sleep stage (also called slow-wave sleep or N3), when growth hormone is released, tissues repair, and the immune system strengthens. Children get proportionally more deep sleep than adults. It's most abundant in the first half of the night.

A network of brain regions active during rest, daydreaming, self-reflection, and mind-wandering. It's important for creativity, self-awareness, and processing social information. Excessive screen time may prevent adequate engagement of the default mode network.

Also known as: major depressive disorder

A mood disorder involving persistent sadness, loss of interest, and other symptoms that affect functioning. Can occur in children and teens, though symptoms may look different (irritability, behavior changes). Treatable with therapy and sometimes medication.

Significant lag in one or more developmental domains (motor, language, cognitive, social-emotional, adaptive). May be temporary or indicate a lasting condition. Early intervention is recommended regardless of whether a specific diagnosis is made.

Comprehensive assessment by professionals to determine if a child has a developmental delay or disability and what services are needed. More in-depth than screening. May involve multiple specialists.

Information about a child's development from conception to present, including pregnancy, birth, milestones, health, family history, and environment. Essential context for understanding current functioning and concerns.

Skills that most children can do by a certain age, used as checkpoints for typical development. Milestones cover motor, language, cognitive, and social-emotional domains. While there's a wide range of normal, significant delays warrant professional evaluation.

Brief assessment to identify children who may need further evaluation for developmental delays. Recommended at 9, 18, and 30 months, plus autism-specific screening at 18 and 24 months. Screens are not diagnostic but flag concerns for follow-up.

An omega-3 fatty acid that is a primary structural component of the brain and retina, comprising about 25% of brain fat. DHA is crucial for brain development, particularly during the third trimester and first two years. Found in fatty fish, algae, and breast milk.

The specific symptoms, behaviors, or characteristics required for a formal diagnosis. Defined in manuals like the DSM-5 (psychiatric) or IDEA (educational). A child must meet criteria to receive a diagnosis, though clinical judgment is also involved.

An interactive reading technique where the adult asks questions, expands on the child's responses, and encourages the child to become the storyteller. More effective for language development than passive reading aloud. Uses prompts like 'what's happening here?'

A balanced approach to technology use that supports rather than hinders well-being. It includes managing screen time, maintaining real-world connections, practicing good digital citizenship, and using technology intentionally rather than habitually.

The Environmental Working Group's annual list of the 12 produce items with the highest pesticide residues. Prioritizing organic for these foods reduces pesticide exposure cost-effectively. The list changes annually but typically includes strawberries, spinach, and apples.

The phenomenon where screen time replaces other activities like physical activity, face-to-face interaction, outdoor play, reading, and sleep. The harm from screens may be less about screens themselves and more about what they displace.

The ability to attend to multiple tasks or stimuli simultaneously. True multitasking is largely a myth—the brain actually switches rapidly between tasks, with costs to performance. This ability develops slowly and is limited even in adults.

A neurotransmitter involved in reward, motivation, pleasure, and movement. Dopamine drives learning by signaling when something is rewarding. Screen time and sugar can dysregulate dopamine systems in developing brains, affecting motivation for less stimulating activities.

A cycle of reward-seeking behavior driven by dopamine release. Digital media, especially social media, games, and short-form video, are designed to trigger dopamine release, creating habits that can be difficult to break and may affect motivation for less stimulating activities.

Also known as: Trisomy 21

A genetic condition caused by an extra copy of chromosome 21. Associated with characteristic physical features, intellectual disability of varying degrees, and higher risk of certain health conditions. Early intervention and inclusive education support development.

Also known as: Diagnostic and Statistical Manual

Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition—the standard classification system for mental health conditions in the US. Contains diagnostic criteria for ADHD, autism, anxiety, and other conditions affecting children.

A learning difference affecting math skills, including number sense, calculation, and math reasoning. Less recognized than dyslexia but similarly common. Early intervention with concrete, hands-on approaches helps.

A learning difference affecting writing, including handwriting, spelling, and/or putting thoughts into written form. May reflect fine motor, language, or both difficulties. Accommodations (typing) and explicit instruction help.

A learning difference affecting reading accuracy and fluency despite adequate intelligence and instruction. Involves difficulty with phonological processing (connecting sounds to letters). Early identification and structured literacy instruction help. Affects 5-10% of the population.

Services for infants and toddlers (birth to 3) with developmental delays or disabilities. Research consistently shows earlier intervention leads to better outcomes. Services may include speech therapy, physical therapy, developmental support, and family training.

Waking consistently before desired wake time, common in children. Causes include light exposure, overtiredness (paradoxically), too early bedtime, or schedule issues. Darkening the room and adjusting bedtime may help.

A diagnostic approach that temporarily removes suspected problem foods, then reintroduces them systematically to identify reactions. Used to identify food sensitivities that may affect behavior, sleep, skin, or digestion. Should be done under professional guidance.

Also known as: electromagnetic radiation

Invisible energy fields produced by electrical devices, WiFi, and cell phones. While research is ongoing, some studies suggest possible effects on developing brains. Precautionary approaches include limiting device proximity to the body, especially during sleep.

Also known as: EQ, emotional quotient

The ability to recognize, understand, manage, and effectively use emotions in oneself and others. Components include self-awareness, self-regulation, motivation, empathy, and social skills. Emotional intelligence is a better predictor of life success than IQ.

The ability to manage and respond to emotional experiences in socially acceptable ways. It develops throughout childhood as the prefrontal cortex matures and includes skills like identifying emotions, calming down when upset, and adapting behavior to different situations.

The words a child knows to describe feelings. A rich emotional vocabulary helps children identify, express, and regulate emotions. Children who can name their feelings ('I'm frustrated' vs. 'I'm mad') manage them more effectively.

The ability to understand and share the feelings of another. Empathy develops in stages: emotional contagion (infancy), egocentric empathy (toddlers), and true empathy (preschool and beyond). It's a foundation of moral development and healthy relationships.

Also known as: hormone disruptors, EDCs

Chemicals that interfere with the body's hormonal system, potentially causing developmental, reproductive, neurological, and immune effects. Common sources include plastics (BPA, phthalates), pesticides, flame retardants, and certain personal care products. Children are especially vulnerable.

Natural pain-relieving and mood-boosting chemicals produced in the brain. Released during exercise, laughter, and positive experiences. Part of the body's reward system and stress management.

An omega-3 fatty acid with anti-inflammatory properties that supports brain health and mood regulation. While DHA is more important for brain structure, EPA appears more beneficial for mood. Together, DHA and EPA provide comprehensive brain support.

A set of cognitive processes including working memory, flexible thinking, and inhibitory control that enable planning, focus, and goal-directed behavior. Executive function develops primarily in the prefrontal cortex and continues maturing into the mid-20s.

Brain changes that occur in response to individual experiences, like learning a skill or language. Differs from experience-expectant development (universal experiences like light for vision). Continues throughout life but is heightened in childhood.

Brain development that requires certain universal experiences (visual input, language exposure, touch) to occur normally. The brain 'expects' these inputs during critical periods. Deprivation during these windows can cause lasting deficits.

The ability to communicate through speech, writing, signs, or gestures. It develops after receptive language and includes vocabulary, grammar, and the ability to form sentences. Delays can have various causes and often respond well to early intervention.

Also known as: FASD, fetal alcohol syndrome, FAS

A range of physical, behavioral, and learning problems caused by prenatal alcohol exposure. There is no known safe amount of alcohol during pregnancy. Effects are permanent and include facial abnormalities, growth problems, and cognitive impairments.

Also known as: developmental programming, DOHaD

The concept that conditions during fetal development can permanently affect physiology and disease risk throughout life. Nutrition, stress, and environmental exposures during pregnancy can 'program' metabolism, stress response, and other systems.

Indigestible carbohydrates that support gut health, blood sugar regulation, and satiety. Most children don't get enough. Found in vegetables, fruits, whole grains, and legumes. Prebiotics are a type of fiber that feeds gut bacteria.

Small muscle movements, particularly in the hands and fingers, that enable activities like writing, buttoning, cutting with scissors, and using utensils. Fine motor development is linked to academic readiness and is supported by activities like drawing, building, and manipulation of small objects.

Meaningful words that children typically produce around 12 months, though the normal range is 8-18 months. First words are usually names for people, objects, or actions in the child's environment. Receptive vocabulary (understanding) develops before expressive vocabulary (speaking).

Chemicals added to furniture, electronics, and textiles to slow burning. Many are endocrine disruptors and neurotoxins that accumulate in dust and bodies. Often found in foam furniture, mattresses, and children's products. Look for PBDE-free products.

Also known as: DIR/Floortime

A developmental approach where adults follow the child's lead in play, joining their interests and gradually expanding interaction. Used to build emotional connection, communication, and thinking skills. Originally developed for autism but applicable broadly.

A mental state of complete absorption in an activity, characterized by focused attention, loss of self-consciousness, and intrinsic enjoyment. Flow occurs when challenge level matches skill level. It promotes learning and is associated with peak performance and well-being.

The ability to think logically and solve novel problems independent of acquired knowledge. It includes pattern recognition, abstract reasoning, and problem-solving. Fluid intelligence peaks in early adulthood and is distinct from crystallized intelligence.

Also known as: folic acid, vitamin B9

A B vitamin essential for neural tube development, particularly critical in the first weeks of pregnancy, often before a woman knows she's pregnant. Adequate folate intake reduces the risk of spina bifida and other neural tube defects by 50-70%. Found in leafy greens, legumes, and fortified foods.

Substances added to processed foods for preservation, color, flavor, or texture. Some additives (artificial colors, certain preservatives) have been linked to behavioral issues in sensitive children. The 'Feingold hypothesis' connects additives to hyperactivity.

Immune system reaction to a food protein, ranging from mild to life-threatening (anaphylaxis). Common allergens include milk, eggs, peanuts, tree nuts, wheat, soy, fish, and shellfish. Requires strict avoidance and emergency planning.

Fear of trying new foods, peaking around age 2-6. An evolutionary adaptation that protected mobile toddlers from poisoning. Children may need 10-15 exposures before accepting a new food. Pressure backfires; modeling helps.

Also known as: food intolerance

Adverse reaction to food that doesn't involve the immune system (unlike allergy) or is non-IgE mediated. Symptoms may include digestive issues, headaches, or behavioral changes. Harder to identify than allergies. Elimination diets can help identify triggers.

The first three months after birth, recognizing that newborns are still adjusting to life outside the womb. Babies benefit from womb-like conditions: holding, movement, warmth, and feeding on demand. Parents need support during this transition period.

Unstructured, child-directed play without adult-imposed rules or goals. Free play develops creativity, problem-solving, self-regulation, and social skills. It has declined significantly in recent decades, with potential consequences for child development.

Mutual, positive relationships between individuals. Children's understanding of friendship evolves: from playmate proximity (preschool) to shared activities (school-age) to intimacy and loyalty (adolescence). Quality friendships protect against loneliness and support development.

Also known as: FBA

Process for understanding why a behavior occurs—what triggers it and what maintains it. Identifies the function (attention, escape, access to items, sensory) to develop effective interventions that teach replacement behaviors.

Also known as: gamma-aminobutyric acid

The brain's main inhibitory neurotransmitter, providing a calming effect. GABA balances excitatory signals, preventing over-stimulation. Low GABA is associated with anxiety. Develops gradually in childhood.

The age of a pregnancy calculated from the first day of the last menstrual period. Full term is 39-40 weeks. Important for tracking development and identifying preterm birth risk. Different from 'fetal age' which starts at conception.

Diabetes that develops during pregnancy in women who didn't previously have diabetes. Affects how cells use sugar and can impact fetal development, potentially causing larger babies and birth complications. Usually resolves after birth but increases later diabetes risk.

Also known as: glial cells

Non-neuronal brain cells that support, protect, and insulate neurons. Include astrocytes, oligodendrocytes (which produce myelin), and microglia (immune cells). Outnumber neurons and are essential for brain function and development.

Also known as: GDD

Significant delays in two or more developmental domains, typically used for children under 5 when a specific diagnosis cannot yet be made. Requires comprehensive evaluation and early intervention services.

The brain's main excitatory neurotransmitter, essential for learning and memory. Must be balanced with GABA. Excess glutamate can damage neurons. MSG (monosodium glutamate) is a related compound in food.

A measure of how quickly a food raises blood sugar levels. Low-glycemic foods (whole grains, vegetables, legumes) provide steady energy, while high-glycemic foods (sugar, white bread) cause blood sugar spikes and crashes that affect mood, energy, and concentration.

The brain's waste-clearing system, most active during deep sleep. It removes metabolic waste products including beta-amyloid (associated with Alzheimer's). This is one reason sleep is essential for brain health and why sleep deprivation impairs cognitive function.

Also known as: palmar grasp reflex

An involuntary grasping response when something touches a newborn's palm. Strong enough that babies can briefly support their own weight. Present at birth, it fades around 5-6 months as voluntary grasping develops.

Brain tissue containing neuronal cell bodies, dendrites, and synapses where information processing occurs. Gray matter volume increases in early childhood, then decreases during adolescence through synaptic pruning, which actually improves efficiency.

Large muscle movements that involve the whole body or major limbs, such as crawling, walking, running, jumping, and climbing. These skills develop in a predictable sequence and are foundational for physical fitness, coordination, and participation in sports and play.

The belief that abilities can be developed through effort and learning, as opposed to a 'fixed mindset' that sees abilities as innate and unchangeable. Children with growth mindsets embrace challenges, persist through difficulty, and see failure as a learning opportunity.

The bidirectional communication network between the gastrointestinal tract and the brain, involving neural (vagus nerve), hormonal, and immunological pathways. The gut produces 90% of serotonin and influences mood, cognition, and behavior.

A brain structure essential for learning and memory formation, particularly the conversion of short-term memories into long-term memories. The hippocampus is highly sensitive to stress hormones and is one of the few brain regions where new neurons continue to form throughout life.

Maintaining adequate fluid intake for body functions. Dehydration affects concentration, mood, and physical performance. Children need reminding to drink as thirst signals develop. Water is the best choice; limit sugary drinks.

The process of developing a clear sense of who you are. Intensifies in adolescence but continues throughout life. Involves exploring options in values, beliefs, relationships, and career. Healthy identity provides a stable foundation for adulthood.

Also known as: Individualized Education Program

Individualized Education Program, a legal document for children with disabilities that outlines educational goals, services, and accommodations. Developed collaboratively between parents and school. Reviewed annually and updated as needed.

Also known as: impulse control, response inhibition

The ability to suppress impulsive responses, resist distractions, and think before acting. Also called impulse control, it develops gradually throughout childhood and is one of the last executive functions to mature. Essential for classroom behavior and social interactions.

Also known as: developmental delay, intellectual developmental disorder

Significant limitations in both intellectual functioning and adaptive behavior, originating before age 18. Ranges from mild to profound. Causes include genetic conditions, prenatal factors, and injuries. Support focuses on maximizing independence and quality of life.

A learning strategy that mixes different topics or types of problems in a single study session, rather than focusing on one topic at a time (blocking). Though it feels harder, interleaving produces better long-term learning and transfer.

Essential mineral for thyroid function and brain development. Deficiency during pregnancy and early childhood can cause cognitive impairment. Found in iodized salt, dairy, seafood, and seaweed. Many populations are mildly deficient.

Also known as: intelligence test

Standardized test measuring general cognitive ability, producing an Intelligence Quotient score with average set at 100. Measures reasoning, problem-solving, and abstract thinking. Scores are influenced by many factors and don't capture all forms of intelligence.

The world's most common nutritional deficiency, particularly concerning in children because iron is essential for brain development, oxygen transport, and energy. Symptoms include fatigue, poor concentration, and developmental delays. Iron needs peak during rapid growth periods.

Also known as: hyperbilirubinemia, neonatal jaundice

Yellowing of a newborn's skin and eyes due to elevated bilirubin, a normal byproduct of red blood cell breakdown. Common in newborns as their livers mature. Mild jaundice is normal; severe cases require phototherapy to prevent brain damage.

The shared focus of two people on the same object or event, achieved through pointing, eye gaze, or verbal reference. A crucial milestone around 9-12 months, joint attention is fundamental for language learning and social development. Deficits are an early sign of autism.

The process by which children learn language, occurring naturally through exposure and interaction. Children progress through predictable stages: cooing, babbling, first words, two-word phrases, and complex sentences. The critical period for language is roughly birth to age 7.

When language development is slower than typical for a child's age. May affect receptive language, expressive language, or both. Causes range from hearing loss to developmental disorders. Early intervention improves outcomes significantly.

Also known as: developmental language disorder, DLD

Difficulty understanding (receptive) or using (expressive) language despite normal intelligence. May affect vocabulary, grammar, or discourse. Different from speech sound disorder. Responds to speech-language therapy.

Lead is a potent neurotoxin with no safe level of exposure. It accumulates in bones and the brain, causing cognitive impairment, behavioral problems, and lowered IQ. Sources include old paint (pre-1978), contaminated soil, some imported products, and old plumbing.

Also known as: intestinal permeability

A condition (intestinal permeability) where the gut lining becomes more permeable, potentially allowing undigested food particles and toxins into the bloodstream. Linked to inflammation, food sensitivities, and potentially behavioral issues. Caused by poor diet, stress, and toxins.

Also known as: learning difference, specific learning disorder

A neurological condition affecting the brain's ability to receive, process, store, or respond to information. Includes dyslexia, dyscalculia, and dysgraphia. Not related to intelligence. Early identification and appropriate instruction are key.

The popular but scientifically unsupported idea that individuals learn better through specific modalities (visual, auditory, kinesthetic). Research shows matching teaching to supposed learning styles doesn't improve outcomes. Better to use varied approaches and active learning strategies.

Brain structures involved in emotion, memory, and motivation, including the amygdala, hippocampus, and hypothalamus. The limbic system develops earlier than the prefrontal cortex, which is why children feel emotions strongly before they can regulate them well.

Also known as: LBW

Birth weight less than 2500 grams (5.5 pounds). Can result from preterm birth or intrauterine growth restriction. Associated with increased health risks and developmental challenges. Causes include maternal nutrition, smoking, and health conditions.

Also known as: Modified Checklist for Autism in Toddlers

Modified Checklist for Autism in Toddlers, a screening tool for autism risk in children 16-30 months. Parent-completed with follow-up interview for positive screens. Does not diagnose autism but identifies children needing comprehensive evaluation.

An essential mineral involved in hundreds of biochemical reactions including muscle and nerve function, sleep regulation, and stress response. Many children are deficient. Magnesium supports calm, focus, and sleep quality.

A hormone produced by the pineal gland that regulates sleep-wake cycles. Melatonin production increases in darkness and is suppressed by light, especially blue light from screens. In children, melatonin release timing shifts during adolescence, causing later sleep preferences.

A heavy metal neurotoxin that accumulates in the food chain, particularly in large predatory fish. Methylmercury crosses the blood-brain barrier and placenta. Most concerning during pregnancy and early childhood. Limit high-mercury fish; choose low-mercury options.

Thinking about one's own thinking—the awareness and understanding of one's cognitive processes. Metacognition enables self-monitoring during learning, recognizing when you don't understand something, and choosing appropriate learning strategies.

Also known as: gut flora, microbiota

The community of trillions of microorganisms (bacteria, fungi, viruses) living in and on the human body, particularly in the gut. The gut microbiome influences brain development through the gut-brain axis, affecting mood, behavior, immunity, and cognitive function.

Tiny plastic particles (less than 5mm) now found in water, food, air, and human bodies. Effects on child development are still being studied, but concerns exist given plastics' endocrine-disrupting properties. Reducing plastic use and filtering water helps minimize exposure.

Present-moment awareness practiced without judgment. Age-appropriate mindfulness training can help children with attention, emotional regulation, and stress. Techniques include breathing exercises, body scans, and mindful movement.

Neurons that fire both when performing an action and when observing someone else perform that action. Mirror neurons are thought to be foundational for imitation learning, empathy, and understanding others' intentions—key aspects of social development.

Changes to what a student is expected to learn, such as simplified assignments or different standards. More significant than accommodations and typically require an IEP. Used when accommodations aren't sufficient.

Fungi that grow in damp environments and release spores that can cause respiratory problems, allergies, and in some cases, neurological symptoms. Children are more vulnerable. Prevention includes controlling humidity, fixing leaks promptly, and ensuring proper ventilation.

The development of values, ethical reasoning, and conscience. Progresses from avoiding punishment (young children) to following rules (school-age) to principled reasoning (adolescence/adulthood). Develops through social interaction, not just instruction.

Also known as: NVP, nausea and vomiting of pregnancy

Nausea and vomiting during pregnancy, typically in the first trimester, actually occurring any time of day. May serve a protective function by avoiding potentially harmful foods. Severe cases (hyperemesis gravidarum) require medical attention.

Also known as: startle reflex

The 'startle reflex' where newborns extend their arms and legs, then curl back in, typically in response to sudden movement or noise. Present at birth and normally disappears by 3-6 months. Persistence may indicate neurological issues.

The study of word formation, including prefixes, suffixes, and word parts that carry meaning. Children learn morphology naturally, adding plurals (-s), past tense (-ed), and other word parts. Overgeneralization errors ('goed' instead of 'went') show active rule learning.

Also known as: praxis

The ability to conceive, plan, and execute a new motor task. Also called praxis, it involves knowing what to do and how to do it. Children with motor planning difficulties may appear clumsy or avoid new physical activities.

Assessment involving multiple professionals from different disciplines (psychology, speech, OT, etc.) to get a comprehensive picture of a child's functioning. Required for many diagnoses and educational classifications.

Using music interventions to address physical, emotional, cognitive, and social needs. A trained music therapist uses singing, instrument play, and movement. Effective for autism, developmental delays, emotional problems, and neurological conditions.

The process of forming a myelin sheath around nerve fibers, which increases the speed of neural signal transmission by up to 100 times. Myelination continues from birth through early adulthood, with different brain regions myelinating at different times. The prefrontal cortex is among the last to fully myelinate.

The ability to tell stories with logical sequence, detail, and structure. Narrative skills develop throughout childhood and predict later reading comprehension and writing abilities. Develop through read-alouds, storytelling, and conversations about past events.

Also known as: neural circuits, neural networks

Connections between neurons that form through repeated activation. The phrase 'neurons that fire together wire together' describes how repeated experiences strengthen these pathways, making behaviors and skills more automatic. This is the basis of habit formation and skill learning.

The embryonic structure that develops into the brain and spinal cord, forming in the first 28 days after conception. Neural tube defects occur when it doesn't close properly. Prevention requires adequate folate before conception and in early pregnancy.

Also known as: EEG biofeedback

A type of biofeedback using real-time displays of brain activity (EEG) to train self-regulation of brain function. Used for ADHD, anxiety, and learning issues. Research is mixed but some children respond well.

The process of generating new neurons. While most neurogenesis occurs prenatally and in early childhood, it continues in specific brain regions (hippocampus, olfactory bulb) throughout life. Exercise, learning, and enriched environments promote neurogenesis.

Brain cells that transmit information through electrical and chemical signals. The brain contains approximately 86 billion neurons. Most neurons are formed before birth, though some neurogenesis continues in specific regions.

The brain's ability to reorganize itself by forming new neural connections throughout life. In children, neuroplasticity is especially high, making early experiences crucial for brain development. This plasticity allows the brain to adapt to new experiences, learn new information, and recover from injuries.

Chemical messengers that transmit signals between neurons. Key neurotransmitters in child development include dopamine (reward and motivation), serotonin (mood and sleep), GABA (calming), and norepinephrine (alertness). Their balance affects behavior, learning, and emotional regulation.

Also known as: neonatal intensive care unit

Neonatal Intensive Care Unit, a specialized hospital unit for premature or critically ill newborns. Provides advanced care including temperature regulation, feeding support, respiratory assistance, and monitoring. Family involvement is encouraged for bonding and development.

Also known as: sleep terrors

Episodes of screaming, intense fear, and thrashing during deep sleep, with no memory upon waking. Different from nightmares (which occur in REM and are remembered). Most common ages 3-8. Usually outgrown. Stress and sleep deprivation trigger them.

Frightening dreams occurring during REM sleep that wake the child. The child remembers the dream and may have difficulty returning to sleep. Normal and common, especially ages 3-6. Reassurance and comfort help; persistent nightmares may indicate anxiety.

Also known as: noradrenaline

A neurotransmitter and hormone involved in alertness, attention, and the stress response. Works with dopamine in attention systems. Imbalances are associated with ADHD and are targeted by some ADHD medications.

Assessment comparing a child's performance to that of a representative sample (norms). Tells you how a child performs relative to peers. Useful for identifying delays or giftedness but doesn't indicate what to teach.

An intuitive understanding of numbers, their relationships, and how they are affected by operations. It includes estimating, comparing quantities, and understanding place value. Strong number sense predicts math achievement and develops through hands-on experiences with quantities.

Systematic watching and recording of behavior in natural or structured settings. A key assessment method for young children. May be informal or use standardized protocols. Provides information about how children function in real contexts.

Also known as: OT

Therapy that helps children develop skills for daily living and learning. Pediatric OT addresses fine motor skills, sensory processing, self-care (dressing, feeding), and classroom skills (handwriting, scissor use). Uses play-based approaches.

Also known as: Obsessive-Compulsive Disorder

Obsessive-Compulsive Disorder, characterized by intrusive unwanted thoughts (obsessions) and repetitive behaviors performed to reduce anxiety (compulsions). Can occur in children and significantly impact functioning. Treated with specific CBT (ERP) and sometimes medication.

The release of VOCs and other chemicals from products into the air, especially noticeable with new furniture, carpets, mattresses, and building materials. Off-gassing is highest when products are new and decreases over time. Ventilation and airing out new items helps.

Essential fats the body cannot produce, critical for brain development and function. Include DHA (brain structure) and EPA (anti-inflammatory). Found in fatty fish, walnuts, flaxseed, and algae. Most children don't get enough.

Also known as: ODD

A pattern of angry/irritable mood, argumentative/defiant behavior, and vindictiveness beyond what's typical for developmental level. Distinguished from normal defiance by frequency, persistence, and impairment. Responds to parent training and family therapy.

When children apply a word too broadly, like calling all four-legged animals 'dog' or all round objects 'ball.' A normal part of language development that shows children are forming categories and learning to refine them as vocabulary grows.

A state of excessive fatigue that paradoxically makes it harder to fall and stay asleep. When children miss their sleep window, stress hormones (cortisol, adrenaline) rise, causing hyperactivity, irritability, and difficulty settling. Preventing overtiredness is often easier than treating it.

Often called the 'bonding hormone' or 'love hormone,' released during positive social interactions, breastfeeding, and physical affection. Promotes attachment, trust, and social connection. Released during skin-to-skin contact.

A stage of play (around 2-3 years) where children play alongside each other but not together, engaged in similar activities without interaction. A normal developmental stage before cooperative play emerges. Shows awareness of peers without requiring social coordination.

Abnormal behaviors during sleep including sleepwalking, night terrors, and sleep talking. More common in children and often outgrown. Usually occur during deep sleep. Safety precautions important for sleepwalkers.

Structured or semi-structured conversation with parents gathering developmental history, concerns, and contextual information. Parents are essential informants as they know their child across settings and over time.

Programs teaching parents strategies to manage child behavior and promote development. Evidence-based programs like Parent-Child Interaction Therapy (PCIT) are highly effective for behavior problems. Involves coaching parents during interactions with their child.

Also known as: infant-directed speech, motherese

The naturally exaggerated, high-pitched speech pattern adults use with babies, characterized by slower tempo, repetition, and elongated vowels. Research shows parentese (distinct from 'baby talk' or nonsense words) supports language development by helping infants detect word boundaries and speech patterns.

Watching content without interaction or learning intent, like background TV or mindless scrolling. It's associated with poorer outcomes than active, intentional screen use. Even 'background TV' can disrupt play and reduce parent-child interaction.

Also known as: Parent-Child Interaction Therapy

Parent-Child Interaction Therapy, an evidence-based treatment for behavior problems in children ages 2-7. A therapist coaches parents in real-time through an earpiece during play, teaching specific skills that improve the parent-child relationship and reduce problem behaviors.

Influence exerted by peers to conform to group norms. Can be positive (encouraging prosocial behavior) or negative (pushing toward risky behavior). Peer influence increases through adolescence and peaks in mid-teens before declining.

Connections between children of similar age. Peer relationships become increasingly important from preschool through adolescence, providing opportunities for learning social skills, developing identity, and gaining independence from family.

A score indicating the percentage of peers a child performed equal to or better than. 50th percentile is average; 75th means the child scored better than 75% of peers. Easier to interpret than standard scores for many purposes.

The ability to understand a situation from another person's point of view. It develops throughout childhood, building on theory of mind. Perspective-taking is essential for empathy, conflict resolution, and mature moral reasoning.

Chemicals designed to kill pests that can affect human health, particularly children's developing nervous systems. Organophosphate pesticides are linked to lowered IQ and ADHD symptoms. Reduce exposure through organic produce, especially the 'Dirty Dozen.'

Also known as: forever chemicals, perfluorinated compounds

A group of thousands of synthetic chemicals that don't break down in the environment or the body. Used in non-stick cookware, waterproof clothing, food packaging, and stain repellents. Linked to immune dysfunction, hormone disruption, and developmental effects.

The ability to hear, identify, and manipulate individual sounds (phonemes) in spoken words. It's a critical pre-reading skill that predicts reading success. Activities like rhyming, segmenting words into sounds, and blending sounds develop phonemic awareness.

A method of teaching reading by connecting sounds with letters or groups of letters. Systematic phonics instruction (teaching sound-letter relationships in a planned sequence) is the most effective approach for most children learning to read.

The ability to recognize and manipulate the sound structure of language at the word, syllable, and phoneme level. Includes rhyming, syllable counting, and sound manipulation. A strong predictor of reading success, distinct from but related to phonemic awareness.

A group of chemicals used to make plastics flexible and in fragrances. They're endocrine disruptors linked to developmental and reproductive issues. Found in vinyl flooring, shower curtains, fragranced products, and some toys. Avoid products with 'fragrance' on labels.

Also known as: PT

Therapy focusing on gross motor skills, strength, balance, and mobility. Pediatric PT helps children with developmental delays, injuries, or conditions affecting movement. Uses exercises, play, and sometimes equipment.

Selective eating common in toddlers and preschoolers, characterized by food refusals and limited variety. Usually a normal developmental phase related to neophobia (fear of new things). Extreme cases may be ARFID. Patience and repeated exposure help.

The organ that develops during pregnancy to provide oxygen and nutrients to the fetus while removing waste. It also acts as a barrier (though not complete) to some harmful substances. Placental health affects fetal growth and development.

A form of therapy using play as the primary means of communication and healing. Children express emotions, process experiences, and develop coping skills through play with a trained therapist. Effective for trauma, anxiety, and behavioral issues.

An educational approach where children learn through play activities rather than direct instruction. Research shows play develops cognitive, social, emotional, and physical skills more effectively than worksheets and drills, especially in early childhood.

The period following childbirth, typically the first 6 weeks. Involves physical recovery, hormonal changes, and adjustment to parenthood. Postpartum depression affects 10-15% of mothers and requires professional support.

The social rules of language use—how context affects meaning, turn-taking in conversation, adjusting speech for different listeners, and understanding nonliteral language. Pragmatic skills develop throughout childhood and are challenging for children with autism or social communication disorders.

Non-digestible fibers that feed beneficial gut bacteria. Found in foods like garlic, onions, leeks, asparagus, bananas, oats, and apples. Prebiotics work synergistically with probiotics to support a healthy gut microbiome.

A pregnancy complication characterized by high blood pressure and protein in urine, typically after 20 weeks. Can be serious for mother and baby, potentially affecting blood flow to the placenta. Requires careful monitoring and sometimes early delivery.

The front part of the brain responsible for executive functions including planning, decision-making, impulse control, and emotional regulation. It is the last brain region to fully mature, not completing development until the mid-20s, which explains many adolescent behaviors.

Significant maternal stress during pregnancy that can affect fetal development through cortisol crossing the placenta. Associated with lower birth weight, premature birth, and potentially altered stress response systems in the child. Stress reduction during pregnancy is protective.

Supplements designed to fill nutritional gaps during pregnancy. Key components include folate (neural tube), iron (blood volume), calcium (bones), DHA (brain), and vitamin D. Should ideally be started before conception.

Also known as: symbolic play, imaginative play

Imaginative play where objects, actions, or people represent something else. Emerges around 18 months and becomes complex by ages 3-5. Pretend play develops creativity, language, social skills, and theory of mind. Also called 'symbolic play' or 'make-believe.'

Also known as: premature birth

Birth before 37 weeks of gestation. Can result in developmental challenges due to incomplete organ maturation, especially of the brain and lungs. Risk factors include multiple pregnancy, infections, and maternal health conditions. Early intervention helps outcomes.

Understanding that print carries meaning and how books work—which way to hold a book, that we read left-to-right and top-to-bottom, that words are separated by spaces. A foundation for reading that develops through book exposure before formal instruction.

Live beneficial bacteria that, when consumed, provide health benefits by supporting the gut microbiome. Found in fermented foods (yogurt, kefir, sauerkraut) and supplements. Different strains have different effects; diversity is generally beneficial.

The rate at which the brain takes in information, makes sense of it, and responds. Processing speed affects academic performance, particularly timed tasks. It generally increases throughout childhood, peaks in early adulthood, and is supported by adequate sleep and myelination.

The body's ability to sense its position and movement in space without visual input. Often called the 'sixth sense,' proprioception is essential for coordinated movement, balance, and body awareness. It develops through active movement, climbing, pushing, and pulling activities.

Voluntary actions intended to benefit others, including helping, sharing, comforting, and cooperating. Prosocial behavior emerges in toddlerhood and is influenced by temperament, parenting, and culture. It's foundational for positive relationships and society.

Essential macronutrient made of amino acids, necessary for growth, tissue repair, enzyme production, and immune function. Children need adequate protein for development. Found in meat, dairy, eggs, legumes, and some grains.

The first movements of the fetus felt by the mother, typically occurring between 16-25 weeks of pregnancy. Earlier pregnancies may feel movement sooner. Movement patterns become important for monitoring fetal wellbeing.

A naturally occurring radioactive gas that seeps from soil into buildings, particularly basements. It's the second leading cause of lung cancer after smoking. Testing is simple and inexpensive; mitigation is effective if levels are high.

The ability to read accurately, quickly, and with expression. Fluency bridges decoding and comprehension—when reading is effortless, cognitive resources are freed for understanding. It develops through practice with text at the right difficulty level.

The ability to understand language—words, sentences, and concepts that are heard or read. Receptive language develops before expressive language; children understand far more than they can say. Delays may indicate hearing issues or language disorders.

Heightened tendency to anxiously expect, readily perceive, and overreact to social rejection. May lead to avoidance of social situations or misinterpreting neutral cues as rejection. Can develop from early experiences of rejection.

Whether an assessment produces consistent results across time, administrators, and scorers. A reliable test gives similar results when repeated. High reliability is necessary (but not sufficient) for validity.

Also known as: active sleep, paradoxical sleep

Rapid Eye Movement sleep, characterized by vivid dreams, rapid eye movements, and temporary muscle paralysis. REM sleep is crucial for memory consolidation, emotional processing, and brain development. Infants spend about 50% of sleep in REM, compared to 20-25% for adults.

The ability to adapt well in the face of adversity, trauma, or significant stress. Resilience is not a fixed trait but develops through supportive relationships, learning coping skills, and successfully navigating challenges. It can be strengthened at any age.

Temporary relief for caregivers of children with special needs, provided by trained respite workers. Essential for preventing caregiver burnout. May be in-home or at a center. Often underutilized but highly beneficial for family wellbeing.

People whose behavior, example, and success children observe and emulate. Can be parents, teachers, peers, athletes, or media figures. Children benefit from diverse positive role models who demonstrate values and possibilities.

A newborn reflex where babies turn toward touch on their cheek and open their mouth, helping them find the breast for feeding. One of several primitive reflexes present at birth that disappear as the nervous system matures.

Temporary support provided to help a child complete a task they couldn't do alone. As competence increases, scaffolding is gradually removed. Examples include physical assistance, verbal cues, modeling, and breaking tasks into smaller steps.

Time spent using devices with screens, including TV, tablets, phones, and computers. The AAP recommends no screens (except video chat) under 18 months, limited high-quality programming ages 2-5, and consistent limits for older children. Quality and context matter as much as quantity.

The optimal attachment pattern where children feel confident their caregiver will be available and responsive. Securely attached children explore freely, seek comfort when distressed, and are easily soothed. About 60-65% of children develop secure attachment.

The ability to focus on relevant information while ignoring distractions. It develops throughout childhood and is crucial for learning in busy environments like classrooms. Selective attention can be trained through practice and is impaired by sleep deprivation.

One's beliefs about oneself—abilities, characteristics, and worth. Develops from infancy through self-recognition to complex self-understanding in adolescence. Influenced by experiences, relationships, and social comparisons.

One's evaluation of self-worth—how much you like and value yourself. Healthy self-esteem is realistic and stable, not inflated or dependent on external validation. Builds through competence, connection, and contribution rather than empty praise.

The ability to manage one's emotions, behavior, and attention independently. It develops from co-regulation experiences and continues maturing into adulthood. Self-regulation underlies success in school, relationships, and life outcomes.

Windows of time when the brain is particularly receptive to certain types of learning, though not as absolute as critical periods. During sensitive periods, learning is easier and more efficient, but can still occur outside these windows with more effort.

Occupational therapy approach helping children process and respond to sensory information more effectively. Uses controlled sensory experiences to help the nervous system organize input. Addresses sensory seeking, avoiding, or processing difficulties.

The brain's ability to receive, organize, and interpret information from the senses (sight, sound, touch, taste, smell, movement, and body position). When sensory processing works well, children respond appropriately to their environment.

Also known as: SPD, sensory integration dysfunction

A condition where the brain has difficulty receiving and responding to sensory information. Children may be over-sensitive (avoiding certain textures, sounds, or movements) or under-sensitive (seeking intense sensory input). Occupational therapy can help.

Distress when separated from primary caregivers. It's developmentally normal, typically appearing around 6-8 months (when object permanence develops), peaking at 10-18 months, and resurging around 2-3 years. It usually resolves with consistent, gentle transitions.

A neurotransmitter that regulates mood, sleep, appetite, and digestion. Approximately 90% of serotonin is produced in the gut, highlighting the gut-brain connection. Low serotonin is associated with depression and anxiety. Sunlight exposure and exercise naturally boost serotonin.

The back-and-forth interaction between child and caregiver that builds brain architecture. Like a game of tennis, the child 'serves' (babbles, gestures, cries) and the adult 'returns' (responds). This responsive interaction is fundamental for brain development and attachment.

Voluntarily giving others access to one's possessions. True sharing (understanding another's desire and choosing to share) typically develops around age 3-4. Before this, forced sharing can actually delay development of genuine generosity. 'Turn-taking' is often more appropriate for toddlers.

Discomfort and inhibition in social situations, especially with unfamiliar people. A temperamental trait that exists on a spectrum. Shy children may need more time to warm up but often form deep friendships. Differs from social anxiety, which is more impairing.

Also known as: kangaroo care, SSC

Placing a naked newborn on the parent's bare chest. Benefits include temperature regulation, stabilized heart rate and breathing, improved breastfeeding, and enhanced bonding through oxytocin release. Recommended immediately after birth and in the following weeks.

The structure and pattern of sleep cycles throughout the night, including the progression through different sleep stages. Children have different sleep architecture than adults, with more time in deep sleep and shorter sleep cycles (45-60 minutes vs 90 minutes).

Conditions or objects that a child has learned to associate with falling asleep. 'Positive' associations (dark room, white noise) support independent sleep. 'Negative' associations (nursing, rocking, parental presence) require recreation at night wakings.

The developmental process by which infants gradually shift from multiple short sleep periods to fewer, longer sleep periods concentrated at night. Most babies consolidate night sleep before nap consolidation.

Recurring patterns of sleep stages throughout the night. Adult cycles last about 90 minutes; infant cycles are 45-60 minutes. Between cycles, brief awakenings are normal—problems arise when children can't return to sleep independently.

Practices and environmental factors that promote quality sleep, including consistent bedtime routines, dark cool rooms, limiting screens before bed, regular wake times, and avoiding stimulating activities close to bedtime.

The time it takes to fall asleep after getting into bed. Normal is 10-20 minutes. Very short latency may indicate sleep deprivation; very long latency may indicate insomnia, anxiety, or sleep timing issues.

Also known as: homeostatic sleep drive

The biological drive to sleep that builds during wakefulness, caused by accumulation of adenosine in the brain. Sleep pressure must reach a sufficient level for easy sleep onset. Too little awake time before bed (low sleep pressure) causes difficulty falling asleep.

A temporary disruption in previously established sleep patterns, often coinciding with developmental milestones, growth spurts, or life changes. Common regressions occur around 4 months, 8-10 months, 18 months, and 2 years. They typically resolve within 2-6 weeks.

Also known as: somnambulism

Walking or performing complex behaviors while remaining asleep, typically during deep sleep. Common in children (up to 15%) and usually outgrown. Safety measures include securing windows and doors. Often runs in families.

Also known as: social phobia

Intense fear of social situations where one might be judged or embarrassed. More impairing than normal shyness. May lead to avoidance of school, activities, and friendships. Treatable through cognitive-behavioral therapy and sometimes medication.

The mental processes used to understand social situations—interpreting others' behavior, predicting responses, and navigating social interactions. Includes theory of mind, perspective-taking, and social problem-solving.

Learning through observation and imitation of others. Children learn behaviors, attitudes, and emotional responses by watching parents, peers, and media. Bandura's social learning theory emphasizes that children don't need direct reinforcement to learn from models.

The ability to identify social problems, generate possible solutions, evaluate consequences, and choose appropriate actions. A learnable skill that develops through guidance and practice. Children who struggle often benefit from explicit teaching.

When infants look to caregivers for emotional cues about how to respond to new situations. Beginning around 8-10 months, babies check a parent's facial expression to determine if something is safe or scary. This shows emerging social awareness and trust.

Abilities needed for effective social interaction: taking turns, sharing, cooperating, reading social cues, managing conflict, and communicating appropriately. Social skills develop through practice and can be explicitly taught when needed.

Structured teaching of social skills through instruction, modeling, role-play, and feedback. May be individual or group-based. Addresses skills like conversation, friendship-making, and reading social cues. Often used for autism, ADHD, or social anxiety.

The lifelong process of learning the norms, values, and behaviors expected in society. For children, primary socialization occurs through family, while secondary socialization involves schools, peers, and media. Children learn social rules through observation and interaction.

A learning technique where information is reviewed at increasing intervals. It leverages how memory works, strengthening recall more efficiently than massed practice (cramming). Apps and flashcard systems can implement spaced repetition automatically.

Difficulty producing speech sounds correctly, making speech hard to understand. May involve substitutions, omissions, or distortions of sounds. Responds well to speech therapy. Different from language disorder.

Treatment for speech, language, and communication difficulties. Addresses articulation, language delays, fluency (stuttering), voice disorders, and sometimes feeding/swallowing. Sessions use play and age-appropriate activities.

Also known as: SLP, speech therapist

A professional who assesses, diagnoses, and treats speech, language, and communication disorders. SLPs work with children on articulation, language development, fluency, voice, and feeding/swallowing issues. They provide therapy and family guidance.

A score converted to a standard scale, typically with mean of 100 and standard deviation of 15. Allows comparison across different tests. Average range is typically 85-115. Used in IQ tests and many developmental assessments.

Assessments administered and scored in a consistent manner, with results compared to a normative sample. Used to measure development, intelligence, achievement, and specific abilities. Results should be interpreted in context.

The body's automatic physiological reaction to perceived threats, involving the release of stress hormones (cortisol, adrenaline). While acute stress responses are adaptive, chronic stress can impair brain development, immune function, and emotional regulation.

Also known as: disfluency, stammering

A speech fluency disorder involving repetitions, prolongations, or blocks in speech. Developmental stuttering is common in toddlers and preschoolers (3-5% of children) and usually resolves naturally. Persistent stuttering benefits from speech therapy.

Also known as: vigilance, concentration

The ability to maintain focus on a task over an extended period. Also called vigilance or concentration. It develops gradually, with school-age children able to sustain attention for about 10-20 minutes on a single task. Regular breaks actually improve sustained attention.

The process by which extra neurons and synaptic connections are eliminated to increase the efficiency of neural transmissions. This 'use it or lose it' process is most active during childhood and adolescence, strengthening frequently used connections while eliminating rarely used ones.

The formation of synapses (connections) between neurons. Occurs most rapidly before birth and in early childhood, with the brain forming millions of new connections per second. Experience determines which synapses strengthen and which are pruned.

The rules governing sentence structure—how words combine to form phrases and sentences. Children acquire syntax naturally through exposure, progressing from single words to complex sentences. By age 5, most children have mastered basic sentence structures.

Intense emotional outbursts typically occurring in toddlers and preschoolers when overwhelmed, frustrated, or unable to communicate needs. They reflect immature emotional regulation systems, not 'bad behavior.' They typically peak around age 2-3 and decrease with language development and emotional maturity.

Designated areas or times where technology is not used, such as bedrooms, mealtime, or the hour before bed. These boundaries help protect sleep, family connection, and mental health by creating predictable screen-free time.

The two-word and short phrases children use around 18-24 months that include only essential content words, like 'more milk' or 'daddy go.' Like telegram messages, they convey meaning without grammatical words. A normal stage in language development.

Any agent that can cause developmental abnormalities in a fetus. Includes alcohol, certain medications, infections (rubella, Zika), radiation, and environmental toxins. The first trimester is the most vulnerable period, but some teratogens affect development throughout pregnancy.

The ability to understand that others have thoughts, beliefs, and perspectives different from one's own. It typically develops around ages 3-5 and is essential for social interaction, communication, and empathy. Pretend play supports theory of mind development.

Also known as: hippotherapy, equine therapy

Using horseback riding for physical, emotional, and cognitive benefits. The horse's movement provides sensory and motor input, while the relationship with the horse supports emotional development. Effective for various conditions including autism and cerebral palsy.

Sudden, rapid, repetitive movements or sounds. Transient tics are common in children and usually resolve. Persistent tics may indicate a tic disorder. Tourette syndrome involves both motor and vocal tics. Stress can worsen tics.

A neurodevelopmental condition involving multiple motor tics and at least one vocal tic lasting more than a year. Often co-occurs with ADHD and OCD. Tics wax and wane. Treatment includes behavioral therapy and sometimes medication.

Prolonged activation of the stress response without adequate adult support. Unlike tolerable stress (brief, buffered by caring adults), toxic stress can alter brain architecture, affect learning and behavior, and increase risk of health problems throughout life.

An approach recognizing the widespread impact of trauma and responding to signs of trauma rather than re-traumatizing. Emphasizes safety, trustworthiness, choice, collaboration, and empowerment. Applicable across settings from schools to medical offices.

One of three periods of pregnancy, each lasting about 13 weeks. The first trimester involves organ formation (highest vulnerability to teratogens), the second focuses on growth and development, and the third prepares for birth with rapid brain growth and lung maturation.

Supervised time when awake infants are placed on their stomachs. It strengthens neck, shoulder, and core muscles needed for later motor milestones like rolling, sitting, and crawling. Recommended from birth, starting with short periods and increasing gradually.

The back-and-forth exchange in games and conversation. An important social skill that develops gradually from infancy through early childhood. It's a precursor to sharing and cooperation, and fundamental to conversation.

Industrial formulations with many ingredients including additives, made mostly from substances extracted from foods. Associated with obesity, metabolic issues, and potentially behavioral effects in children. Examples include most packaged snacks, fast food, and sugary drinks.

When children apply a word too narrowly, like 'cup' referring only to their own cup. Less common than overextension, it also reflects the process of learning word meanings and categories.

The practice of swabbing a cesarean-born baby with maternal vaginal fluids to potentially transfer beneficial microbes. Research is ongoing—some studies show microbiome effects, but safety and long-term benefits are not yet established.

Whether an assessment measures what it claims to measure. A valid reading test should predict reading ability; a valid behavior scale should capture actual behavior. Essential quality of any useful assessment.

Unpredictable rewards that are more addictive than predictable ones. Social media notifications, game loot boxes, and infinite scroll use variable rewards to maximize engagement. This mechanism is particularly powerful in developing brains.

The waxy white coating covering a newborn's skin, providing protection in the womb and during birth. It has antimicrobial properties and helps with temperature regulation. Current guidance suggests delaying washing to preserve its benefits.

The sensory system in the inner ear that detects head position and movement, providing the sense of balance and spatial orientation. It influences posture, eye movements, and coordination. Swinging, spinning, and climbing activities stimulate vestibular development.

The finding that young children (under 3) learn less from video than from live interaction, even when content is identical. The effect decreases with age but suggests that screens are poor teachers for toddlers, regardless of educational intent.

A fat-soluble vitamin essential for bone health, immune function, and brain development. Unlike other vitamins, it's primarily synthesized through sun exposure. Deficiency is common, especially in children with limited outdoor time, darker skin, or in northern latitudes.

The number of words a person knows. Children's vocabulary grows from about 50 words at 18 months to thousands by school entry. Breadth is important for reading comprehension—children need to recognize most words in a text to understand it.

The richness of word knowledge—understanding a word's multiple meanings, how it relates to other words, and how to use it in different contexts. Deeper vocabulary knowledge supports better reading comprehension and writing.

Also known as: word spurt, naming explosion

The rapid increase in vocabulary that typically occurs between 18-24 months, when children may learn 10+ new words per day. Children go from about 50 words to several hundred within months. Also called the 'word spurt' or 'naming explosion.'

Chemicals that easily become gases at room temperature, released from paints, furniture, cleaning products, and building materials. VOCs contribute to indoor air pollution and can cause respiratory irritation, headaches, and potential long-term health effects.

The appropriate amount of awake time between sleep periods for a child's age. Age-appropriate wake windows build sufficient sleep pressure without causing overtiredness. They lengthen with age: newborns 45-60 minutes, 1-year-olds 3-4 hours, toddlers 5-6 hours.

Brain tissue composed of myelinated nerve fibers that connect different brain regions. White matter develops throughout childhood and adolescence, enabling faster and more efficient communication between brain areas. It's crucial for complex cognitive tasks requiring coordination between regions.

Consistent background sound that masks other noises and may improve sleep. Can be helpful for light sleepers or noisy environments. Should be at safe volume levels (under 50 dB). Some children don't need it.

Research showing that children from higher socioeconomic backgrounds hear significantly more words by age 3 (the original '30 million word gap' study). While exact numbers are debated, the quality and quantity of language exposure affects vocabulary and later academic success.

The ability to hold and manipulate information in mind over short periods. Working memory is essential for following instructions, mental math, reading comprehension, and problem-solving. It can be strengthened through practice and is affected by sleep and stress.

An essential mineral involved in over 300 enzymatic reactions, including brain development, immune function, and wound healing. Zinc deficiency can impair growth, immune function, and cognitive development. Found in meat, shellfish, legumes, and seeds.

Also known as: ZPD

The gap between what a child can do independently and what they can do with guidance. Coined by Vygotsky, learning is most effective in this zone—tasks challenging enough to promote growth but not so difficult they cause frustration. Scaffolding helps bridge this gap.