This is a classic example of Betteridge's law. Edit: QED >It seems that the question "When does intelligence peak?" is actually a rather meaningless question.

This is a classic example of Betteridge's law. Edit: QED >It seems that the question "When does intelligence peak?" is actually a rather meaningless question. Not only do our various cognitive functions peak at different times, but past a certain age it might make more sense to view adult intelligence not through the lens of youthful general processing speed and reasoning, but through the lens of expertise, wisdom, and purpose.