[dragonwriter]

> The things humans attempt to learn in modern times however (non-native languages, formal systems of logic, the ability to argue and reason in complex fashions, the ability to program complex systems) are completely evolutionarily unprecedented, and the result is clear: children are not able to acquire these behaviours effortlessly.

At least in the case of non-native languages, while it may not be "effortless", every study I've seen has indicated that it is much easier for children to learn them.