The kicker came in 2010 when primatologists Robert Sussman and Joshua Marshack (2010) reviewed all the data of three major, long-running chimpanzee studies and found infanticide to be “extremely rare”—there were 17 instances, to be exact, in 215 total years of observation. They concluded that “the data for infanticide…are so sparse…[that] both the evidence and the interpretations are suspect” (pp. 23–24).
This got us to wondering about human beings. New advances in human evolution have shown that contrary to the 1970s thinking of human ancestors as violent nomadic groups whose males fought each other over females, it is now known that they lived in pair-bonded or monogamous, relatively peaceable societies for at least the last 4 million years. And, they were nothing like chimpanzees. For example, contrary to the popular view, humans’ ancestors never knuckle-walked. Chimpanzees and gorillas developed that mode of locomotion independently, long after they had diverged from the human lineage. Human beings’ DNA is 97% identical to that of orangutans, which do not knuckle-walk and whose ancestors never did, either, and no one is comparing human behavior to that of orangutans.
Have the general ideas of male aggression and the need for females to protect against it unduly influenced thinking about the evolution of the human species? Have obsolete ideas from sociobiology influenced professionals’ thinking about modern human behavior? Have they influenced public perceptions? Do males get something else from monogamous relationships besides exclusive access to sex with their mate—love, perhaps, or the satisfaction of fatherhood, or a good meal? As recompense for limiting their mating opportunities, do females get something else from their mate besides an economic advantage—love, possibly, or help with child rearing?
We keep thinking about how Homo erectus, modern human beings’ immediate predecessor, managed to walk all the way from Africa to Java, and from there to China (Rightmire, 1993). The cooperation and sharing of child rearing and household chores needed to meet the challenges of such an adventure seemed inconsistent with a relationship based on fear