A community-sourced wiki dedicated to offering a comprehensive understanding of the science of mental ability.
Start here for a concise overview of psychometric science.
Quick answers to the most common psychometric queries.
Addressing various IQ misconceptions which have permeated pop culture.
Explore the general intelligence factor and its empirical support.
Essential stats concepts needed to interpret test data accurately.
Milestones in measuring general intelligence across history.
Clear answers to common IQ and psychometrics questions: what IQ measures, how g and reliability work, why scores vary, genetics vs environment, test rankings, online test accuracy, bias concerns, and interpreting index profiles.
An in-depth analysis of the WWII Army General Classification Test, showing high g-loading, strong validity, no Flynn Effect, and robust performance against modern IQ tests.
A research synthesis on IQ and schooling: early interventions, fade-out effects, causal estimates of years of education, and why education tends to change specific abilities more than g.
How nutrition, supplements, toxins, alcohol, and head injury affect intelligence - what raises IQ, what harms cognition, and which effects are permanent.
