The mouth-agape gesture is so quotidian and universal that it seems like it should already have one of those prosaic sidebars in a high school biology textbook. However, scientists have still not fully cracked the relative mystery behind the yawn (notably, some have argued it’s a tool for regulating brain temperature) or figured out why a single occurrence of the phenomenon can ricochet across a crowded room so easily.
Previous research has suggested that contagious yawning is positively correlated with empathy, but a new study from Elizabeth T. Cirulli and Alex J. Bartholomew at Duke’s Center for Human Genome Variation that examined multiple variables finds no such connection. In fact, the new analysis, published last Friday in PLOS ONE, concludes that age is the only variable with even modest explanatory power. Younger people are more likely to yawn than older ones, but the amount of variance this statistical relationship explains is decidedly underwhelming.
via Pacific Standard
