The Babbling Stage of Infancy

It is interesting and perhaps surprising to realize that most mammals lack a capacity for complex vocal learning of this sort. Current research suggests that aside from humans, only marine mammals (whales, dolphins, seals), bats, and elephants have it. Among primates, humans appear to be the only species that can hear new sounds in the environment and then reproduce them. Our ability to do this seems to depend on a babbling stage during infancy, a period of vocal playfulness as instinctual as...