Why do two people of the same age have such different brains?
Published:
As people live longer, more and more individuals reach old age without ever developing dementia. That is good news. But it has opened a quieter, more interesting puzzle: even among adults who never cross the threshold into disease, aging does not look the same for everyone. Two people who share a birth year can have brains and cognitive profiles that look strikingly different, and those differences tend to widen as we follow people over time rather than narrow.
