Have you ever been beaten at the classic word game Scrabble by an 85-year-old grandmother? (I have, and I’m usually pretty good at wordsmithing.) Some elderly people with super-sharp memory don’t seem to suffer the memory loss that assails most people as they age. Why?
PEARCE: In maybe three or four decades or so, we’ll be choosing such traits as the average hedonic set point of our children. Over time, I think allelic combinations [suites of variant copies of mission-critical genes] that leave their bearers predisposed to unpleasant states of consciousness — unpleasant states that were genetically adaptive in our ancestral environment — will be weeded out of the gene pool.