The behavior geneticist Kathryn Paige Harden is waging a two-front campaign: on her left are those who assume that genes are irrelevant, on her right those who insist that they’re everything.

On the book that Hitler called his “bible” and the man who wrote it.

On the eugenicist and the Mellon family heiress who built the anti-immigrant policy agenda that Trump is now implementing.

On the fear-mongering history of sex education.