Heritable IQ is Boosted by Environment, Just Like Height

hough it’s not easy to pinpoint the causes of the rise in IQ scores, it’s no paradox that a heritable trait can be boosted by changes in the environment. That’s what happened with height, a trait that also is highly heritable and has increased over the decades, and for some of the same reasons: better nutrition and less disease. Brains are greedy organs, consuming about a fifth of the body’s energy, and they are made of fats and proteins that are demanding for the body to produce. Fighting of...

 Scientific Reasoning Explains Increases in IQ

The bombshell is that the Flynn Effect is almost certainly environmental. Natural selection has a speed limit measured in generations, but the Flynn Effect is measurable on the scale of decades and years. Flynn was also able to rule out increases in nutrition, overall health, and outbreeding (marrying outside one’s local community) as explanations for his eponymous effect.241 Whatever propels the Flynn Effect, then, is likely to be in people’s cognitive environments, not in their genes, diets...

 The Biggest Gains in g

It is one thing if a child’s IQ is elevated over time because she is drilled daily on vocabulary and basic number facts (two of the subtests of major IQ batteries). But Flynn and others have shown that these are not the areas where IQ has risen much. It is in what Flynn refers to as “on-the-spot reasoning” about relations between objects that are either totally familiar to everyone, hence no one can be claimed to have a prior advantage (e.g., arranging familiar pictures so they tell a coheren...

 Rolling Triggers and Social Multipliers Explain the Flynn...

The most potent facet of our environment is other people. When something, perhaps the popularity basketball got from television, triggered greater participation in basketball, the average performance rose as individuals played more and got better. Initially, a few people learn to shoot with either hand, then others imitate them. The rise in average performance feeds back into a new challenge for each individual. Those who want to excel have to learn to pass with either hand and this spreads a...