In the 1980s, two Italian researchers—Gabriele Schino (of the Institute of Psychology at Italy’s National Research Center) and Filippo Aureli (from the University of Rome)—were conducting research on yawning. They knew that some primate species exhibit a gender difference in yawn frequency, and they had a theory that this was triggered by a difference in the size of their canine teeth. To test this theory, they began to study the closest primate species available: humans. They had their team ride the trains in Rome, carefully observing and recording all yawns, even notating which were covered and uncovered. Their results? There is absolutely no difference between men and women in the frequency of yawning. But don’t you feel better knowing how thoroughly the question was researched? Thank you, science.