Most anthropologists now accept that cooperative breeding (not monogamous pairs) were how early humans lived and thrived. Sarah Hrdy, whom I know you respect, wrote an entire book about it called Mothers and Others.

“For as long as she’s been a sociobiologist, Sarah Blaffer Hrdy has been playfully dismantling traditional notions of motherhood and gender relations… Hrdy is back with another book, Mothers and Others, and another big idea. She argues that human cooperation is rooted not in war making, as sociobiologists have believed, but in baby making and baby-sitting. Hrdy’s conception of early human society is far different from the classic sociobiological view of a primeval nuclear family, with dad off hunting big game and mom tending the cave and the kids. Instead, Hrdy paints a picture of a cooperative breeding culture in which parenting duties were spread out across a network of friends and relatives. The effect on our development was profound.”—Julia Wallace, Salon