Who knows what's really going on inside babies' heads? Parents and scientists alike are obsessed with cracking the bambino code. It's hard to tell, of course, because babies can't talk. But the more clever ways we find to peek into the minds of babies, the more astonished we are at how much they seem to know and how much they can do. For example, did you know babies can tell when you're fake smiling? Here are five surprising things babies know.
1. As early as 18 months, babies know when an emotion fits with an experience. They can tell when you're trying to mask feelings of distress, or when you're fake-smiling through a negative experience.
2. Babies recognize their mother's voice from the womb. It's part of the work brains do while preparing to learn language -- babies are taking in speech patterns of their mothers. They may know the difference between familiar and unfamiliar words.
3. By 6 months babies know the difference between good and evil. Apparently your moral code isn't all nurture -- a recent study suggests it might be hardwired into our brains. Babies in the study showed a strong preference for "good" or helpful characters in a puppet play over "bad" or harmful characters.
4. Babies are born knowing how to swim, some people say. At least, babies seem to know not to breathe in when their faces are underwater.
5. Babies know math. As early as 5 months old, babies have a rudimentary understanding of simple addition and subtraction.
What else have you been surprised to learn that babies already know?
Image via Arman Zhenikeyev/Corbis