Module 29

Flynn Effect Awareness Sheet

How IQ scores shift over time and what modern tests actually measure

What Is It

IQ scores have risen ~3 points per decade since testing began in the early 1900s

Named After

James Flynn, NZ political scientist who documented the trend in 1984

Largest Gains

Fluid reasoning and abstract problem-solving (not vocabulary or knowledge)

Recent Reversal

Some countries show a 'reverse Flynn Effect' -- scores declining since the 1990s

IQ Score Trends by Decade

Decade	Avg IQ (Re-Normed)	Trend	Likely Drivers
1930s	~80 (by modern norms)	Baseline	Limited education, nutrition deficits
1950s	~85-90	Rising	Better nutrition, expanded schooling
1970s	~92-95	Rising	Reduced lead exposure, more cognitive demands
1990s	~98-100	Rising	Technology, information access, smaller families
2010s	100 (normed)	Flat/declining	Norms reset; some countries show decline
2020s	~97-100 (est.)	Slight decline	Screen time, reduced play, sleep deficits?

If your child is tested with an older version of a test (norms from 5+ years ago), their score may be artificially inflated by 2-5 points. Always ask which norm year the test uses.

Modern IQ Test Comparison

Test	Age Range	What It Measures	Duration
WISC-V	6-16 years	Verbal comprehension, visual-spatial, fluid reasoning, working memory, processing speed	60-90 min
WPPSI-IV	2:6-7:7 years	Same domains adapted for younger children	30-60 min
Stanford-Binet 5	2-85+ years	Fluid reasoning, knowledge, quantitative, visual-spatial, working memory	45-75 min
KABC-II	3-18 years	Sequential processing, simultaneous, planning, learning, knowledge	30-75 min
DAS-II	2:6-17:11 years	Verbal, nonverbal reasoning, spatial, working memory, processing speed	45-65 min
CogAT	5-18 years	Verbal, quantitative, nonverbal reasoning (group-administered)	30-60 min

Testing Limitations

IQ tests measure a snapshot, not a ceiling. A child's score can shift 10-15 points between testing sessions due to sleep, anxiety, rapport with the examiner, and time of day. Never treat a single score as a permanent label.