We've all been told not to yawn. But according to new study animals with bigger brains longer the length of their yawns. Therefore, longer the yawn, more intelligent the anim al. Researchers from the State University of New York in the US looked at the videos of 2 9 mammals yawning to calculate the average length of their yawns. The animals had their brain weight already documented in an earlier research When the researchers squeezed the numbers, they realised that brain weight and the number of neurons in the outer layer of the brain called cortex can constantly predict yawn length. For instance, gorillas, horses, walruses and African elephants may have huge sizes but they have shorter yawns than humans because the sizes of their brains are smaller compared with our s T he findings also told us that the length of yawn does not correlate to the size of the body but to the size of the brain, 'Tech Times' reported. The research team led by Andrew Gallup , from the Stat...