Why have thoroughbreds topped out in speed

Roger Pielke at FiveThirtyEight explores some possible reasons why thoroughbred racehorses seem to have peaked in speed.

One possibility, advanced by Denny and others, is that thoroughbred race times may have leveled off because the narrow genetic diversity of racehorses limits the genetic diversity in the pool of potential thoroughbred champions. Modern thoroughbreds are descendants of a small number of horses (less than 30 in the 18th century), and 95 percent are thought to trace their ancestry to a single horse, The Darley Arabian. Today, there are fewer than 25,000 thoroughbreds born each year in the United States. Compare that with the more than 7 billion people worldwide.3 The size of the human population may simply lead to a greater number of potential athletes with extreme speed.

And humans could be even faster if we didn’t engage in any other athletic pursuit aside from racing. David Epstein wrote in his book “The Sports Gene” that while it’s unclear whether speed is innate or nurtured, one important reason for Jamaican athletes’ success in short-distance races is that in their country, “every kid is made to try sprinting at some point.” In the United States, at least, many of the fastest runners are lost to other sports, and thus never have a chance to reach their potential as runners. Epstein cites Trindon Holliday, now a kick returner for the New York Giants, who in college outran future Olympic bronze medalist Walter Dix at 100 meters at the 2007 USA Outdoor Track and Field Championships. Who knows how fast Holliday might have become as a full-time professional sprinter? Humans who race also have many opportunities to train, specialize, experiment and innovate. Those efforts are apparently still bearing fruit in some track and field events.

It's an analogy so take it as more clever than elucidating, but I see parallels with genetic diversity and intellectual diversity. Having a team with a broader set of backgrounds, ideas, and strengths seems a way of avoiding groupthink, a form of the local minimum trap that results from genetic diversity in athletic accomplishment.