Scientists have found that the duration of a yawn varies with the size of the brain depending on its need for cooling,
Experts conducted an experiment on 55 mammal and 46 bird species, thus studying 1,291 yawns.
Based on the results of phylogenetic analysis, scientists have found a solid connection between the duration of the yawn and the number of neurons.
They concluded that a larger brain has a higher demand for thermolysis, while its temperature is partly determined by the release of heat due to neuronal activity.
The experts also noted that animals yawn longer than birds due to their higher body temperature.