to live and to mate.
Evolutionary theory does not paint a clear picture for mate selection. If the theory was completely comprehensive, all males would leave after around four years (when the child is old enough to be cared for by others) and all females would fight over the one alpha male. This is not true in humans. Evolutionary theory does not explain why one man may be right for one woman but not for another. It fails to give reason for people who stay together and cannot have children. It does not explain why a father seems to be such an integral part of a child’s normal, healthy development. There is something else there. There is something that holds two people together, and contrary to what it may seem, works hand in hand with evolutionary theory.
Along human’s evolutionary tract an adaptation occurred that allowed babies to be born prematurely. It was an exceptionally advantageous adaptation. The smaller head of an immature brain was easier to pass through the birth canal. Prematurity made birth easier and allowed more babies and more mothers to survive the trauma of childbirth. This was evolutionarily productive, but it created many new problems for the parents because this premature infant needed drastically more care and protection to survive. If left on its own, the infant would die of starvation or be attacked by a predator. This meant that the new parents would have to look after and care for their new infant. A mechanism was needed to foster a bond between caregiver and child.
Bowlby (1988) created the theory of attachment. He proposed that there was an innate mechanism to foster an attachment bond to keep the caregiver with the child and to keep the child near the caregiver. When a baby is born, they have needs to be met.