Organisms may be buffered against a range of alterations in their fitness landscapes by harboring a hierarchy of epistatic couplings among genes or traits.#
For a fixed mutation rate, as the complexity of the entities under selection t increases, the number of “bad” alleles which accumulate increases as t2.#
The impulse to think that environmental sources of difference are less threatening than genetic ones is natural but illusory.#
Heritability describes something about a population of people, not an individual. It makes no more sense to talk about the heritability of an individual’s IQ than it does to talk about his birthrate.#
The more we succeed in giving every youngster a chance to develop his or her latent cognitive ability, the more we equalize the environmental sources of differences in intelligence. The irony is that as America equalizes the circumstances of people’s lives, the remaining differences in intelligence are increasingly determined differences in genes.#