Does education help build a cognitive reserve to ward off dementia?

In 1972, the UK government raised the minimum school-leaver’s age from 15 to 16, with the goal of giving more students intellectual skills for modern occupations. Now, as these teens pass though their sixties, another benefit may be emerging: a lower risk of dementia. But with research from other groups muddying the waters, this relationship is far from clear-cut.

The idea that education protects against dementia isn’t new. Yaakov Stern at Columbia University in New York proposed it in…