James R. Flynn’s observation that IQ scores experienced dramatic gains from generation to generation throughout the 20th century has been cited so often, even in popular media, that it is becoming a cocktail party talking point. Next stop a New Yorker cartoon. (An article about Flynn and the Flynn effect has already been published in The New Yorker.)
A recent report in Trends in Genetics (part 1 and part 2) takes a bleaker view of our cognitive future—one that foresees the trend line proceeding inexorably downward. Gerald Crabtree, a biologist at Stanford University, has put forward a provocative hypothesis that our cushy modern existence—absent the ceaseless pressures of natural selection experienced during the Paleolithic—makes us susceptible to the slow creep of random genetic mutations in the the 2000 to 5000 genes needed to ensure that our intellectual and emotional makeup remains intact. The implications of this argument are that we as a species of the genus Homo are over many generations slowly losing our sapiens.
View the original article here: Homo (Sans) Sapiens: Is Dumb and Dumber Our Evolutionary Destiny?