Math is needed to find causal relationships beyond the perceptual level, and some number of levels above the perceptual. Here some researches use it to study a hypothesis.
In “Yawning cools the brain,” (Discovery News, Tuesday, 16 December 2008) Jennifer Viegas says:
For the bird study, the scientists exposed parakeets to three different conditions: increasing temperature, high temperature and a control temperature.
While yawning did not increase during the latter two conditions, it more than doubled when the researchers increased the bird’s ambient temperature.
“Based on the brain cooling hypothesis, we suggest that there should be a thermal window in which yawning should occur,” says Gallup.
It’s now believed yawning operates like a radiator for birds and mammals.
Ab0ut studying parakeets, they say:
He and colleagues Michael Miller and Associate Professor Anne Clark analysed yawning in parakeets as representative vertebrates because the birds have relatively large brains, live wild in Australia, which is subject to frequent temperature swings, and, most importantly, do not engage in contagious yawning, as humans and some other animals do.
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