of aggression. This is especially so with regard to the transport of infants who, because of the delayed development mandated by humans’ huge brains, took many years to mature enough to travel independently. A woman could not carry one infant and lead several toddlers and dependent children very far, especially on journeys involving crossing large rivers and navigating seas, as H. erectus did. She needed help, and an infanticidal male would not have been the mate of choice. She needed more than help: She needed a long-term commitment. Why would he make such a commitment? These questions were the genesis of this book.
