Evolution
The strong grip of a baby is another example. It is a vestigial reflex, a remnant of the past when pre-human babies clung to their mothers' hair as the mothers swung through the trees. Human babies' feet curl up when they are sitting down, while primate babies can grip with their feet as well. All primates except modern man have thick body hair which an infant can grasp, unlike modern humans. The grasp reflex allows the mother to escape danger by climbing a tree using both hands and feet.