The biology of fatherhood

Dads today are spending more time changing diapers, tying shoes and pushing swings — nurturing acts that a new book argues have long been part of men’s biological nature.Why it matters: Fathers are relatively new scientific subjects, and new findings are expanding our understanding of parenting, primatologist Sarah Blaffer Hrdy writes in “Father Time: A Natural History of Men and Babies.”Hrdy spent decades studying primate mothers, what it means to be “maternal,” and the role of alloparents, which are male or female group members who care for young who aren’t their offspring, and their…