"The males among these large, gray-haired monkeys were killing their own
colony’s infants; at the time, in the late 1960s and early 1970s,
researchers thought the pressures of overcrowding were the cause. What
Hrdy found, however, was that these langurs’ infanticidal tendencies
were actually adaptive behavior—behavior that, she argues, one can also
see in humans."
Why Primates Kill Their Offspring