She Has Her Mother's Laugh: What Heredity Is, Is Not, and May Become

by Carl Zimmer

The word race seems to have first taken on a modern complexion during the Habsburg rule of Spain.

It turned out that the rats that made more stress hormones had been licked less as pups by their mothers.

Meaney and his colleagues found that the brains of people who had experienced child abuse had relatively more methyl groups around their receptor gene, just as in the case of the under-licked rats. And just as those rats produced fewer receptors for stress hormones, the neurons of victims of child abuse had fewer receptors as well. It’s conceivable that the child abuse led to epigenetic changes that altered emotions in adulthood, snowballing into suicidal tendencies.