• People used to think babies were illogical and in fact we've discovered that even young babies can use sophisticated logic and thinking to figure out how the world works.

• We used to think children were egocentric and they couldn't take the perspective of another person. But we've discovered even very young children can understand that people might want something different from what they want themselves.

• We used to think that children were amoral and that they didn't understand about morality until they were adolescents. But we've discovered that two- and three-year-olds are empathetic and altruistic.

(Provided by Alison Gopnik, a professor and the director of the Cognitive Development Lab at the University of California at Berkeley).