It includes a series of highly specific inbuilt assumptions that enable them to learn grammar from examples, without ever being taught it. Hence the tendency to learn grammatical language is human nature. But a child reared in isolation does not start to speak Hebrew unaided. In this combination of nature and nurture, argue the Darwinian psychologists, language is typical of most human traits. Nor will the Darwinian psychologists concede that to believe in nature is to be a Hobbesian fatalist and that to believe in nurture is to be a Rousseau-ist believer in the perfectibility of man.
History suggests otherwise.
The making of macho Physiologists have also begun to add weight to the nature side of the scale with their discovery of how the brain develops. The brain of a fetus is altered by the child's genes, by its and its mother's hormones and, after birth, by its learning. The hormone is nurture, in the sense that it can be altered by injections or drugs taken by the mother. But it is nature in the sense that it is a product of the body's biology. This discovery has gradually altered the views of many psychologists about sex and education.