Infants may not be capable of quantum mathematics, but they very well may be capable of deeper insights than once thought. Oh, and European girls are now hitting puberty around nine. Do we need to rethink our basic notions of human development?

The baby news comes from philosopher Alison Gopnik whose book, The Philosophical Baby, holds that infants lead far more insightful lives than adults begrudge them. Following Bayesian theory, Gopnik posits that babies are constantly testing causation. The way they handle causation is often in the realm of the imaginary. "If I push the red truck, the red truck rolls," goes the one-year-old's thinking. "And if do it in the air, it will fly."

First lesson for the toddler set: trucks can't fly. The way babies test imagination constructs their conception of reality, Gopnik argues, which undercuts the common theory--popular since Freud--that infants cannot discern between imagination and reality.

Danish researchers have discovered the average age of breast development has dropped to under ten years in Danish girls compared to what it was just ten years ago. The research does not conclude why the earlier start to womanhood is occurring, but Danes are certainly becoming teenagers earlier--something that also might lead to tests of causation.