Wouldn’t it be great if there was some infallible trick to calm a crying baby? According to science, there just might be. (Get on your walking shoes.)
Human feet are unique in the ape family, made for walking instead of grasping. For our babies this means two fewer grasping limbs to help cling to their mother, which means that during the evolution of bipedalism, infants had a harder time hanging on. How did our ancestors survive?
Why is it that some mammals can just leave their babies in a den or nest, while others carry theirs around (or have them cling on) through out the day?