Your Yawn May Reveal How Smart You Are

A new study has found that the length of a yawn can indicate how big your brain is, and how many neurons you have. These say researchers, could explain why humans yawn longer than other mammals. The research conducted is based on the fact that animals, such as gorillas, hippos, and elephants – which are bigger than humans but have a proportionately smaller brain – all yawn for a shorter durations than humans. This led to the hypothesis that brain size – rather than head or body size – is likely to yawn length. The researchers scanned YouTube to find a bunch of different animals yawning. In the end, they studied over 205 yawns from 177 individuals across 24 taxa. They found that mice had the shortest yawns, lasting, on average, 0.8 seconds, and humans had the longest, lasting an average of 6.5 seconds. Camels came in second and dogs in third.