View full lesson: http://ed.ted.com/lessons/why-is-yawning-contagious-claudia-aguirre *Yaaawwwwwn* Did just reading the word make you feel like yawning yourself? Known as contagious yawning,...
========== Oh, excuse me! Have you ever yawned
because somebody else yawned? You aren't especially tired, yet suddenly your mouth opens wide and a big yawn comes out. This phenomenon is known
as contagious yawning. And while scientists still
don't fully understand why it happens, there are many hypotheses
currently being researched. Let's take a look at a few
of the most prevalent ones, beginning with two
physiological hypotheses before moving to a psychological one. Our first physiological hypothesis states that contagious yawning
is triggered by a specific stimulus, an initial yawn. This is called fixed action pattern. Think of fixed action pattern
like a reflex. Your yawn makes me yawn. Similar to a domino effect,
one person's yawn trigger...