The question isn't as crazy as it sounds. After all, if some species of birds hatch chirping a chorus their elders understand, why aren't babies born talking? Experience tells us that a baby won't speak for about a year, and that when she does, her first words are likely to be choppy substitutes, such as "ba" for bottle or "wa" for water. So what gives?
According to the researchers who take those funny babbling sounds seriously, it's not that humans are late bloomers so much as they're early arrivals. Steven Pinker, a professor of psychology at the Massachusetts Institute of Technology and author of The Language Instinct, explains that babies' brains aren't fully mature when they're born. "We squeeze out our babies when they're kind of half-baked," he says, "because humans have large heads, and women's pelvises can only accommodate them up to a certain size." Moreover, Pinker adds, if babies could communicate at birth, what language would they speak? "Language has to be coordinated with other people; babies can't just be born speaking Esperanto."
Linda Weber is a San Francisco-based freelancer who writes frequently about psychology and health.