>crystallized knowledge (as measured by New York Times crosswords, for example) climbs sharply between ages 20 and 50 and then plateaus, even as the fluid kind

>crystallized knowledge (as measured by New York Times crosswords, for example) climbs sharply between ages 20 and 50 and then plateaus, even as the fluid kind (like analytical reasoning) is dropping steadily — by more than 50 percent between ages 20 and 70 in some studies. That seems very strange, because it contradicts my own experience completely. As I grow older my ability to remember things gets worse, but my ability to understand and reason about things has gotten so much better it's not subtle at all. Now, of course it is very possible that my sample size of 1 is slightly inadequate to draw any conclusions at all. But I would have expected that at least the direction of the trend would have to be the same for all individuals.