Yawning, an act so simple yet intriguing, holds a peculiar secret—it's contagious not just between humans but between humans and dogs as well. In our book, The Purest Bond: Understanding the ...

Researchers believe the yawning robot may have triggered some biological mechanism in the chimps that they associated with sleep. Image: Popular Science composite, Getty Images/ RMJM, Aline ...

Yawning isn’t the only bodily function that’s contagious. Japanese scientists have discovered that chimpanzees are more likely to urinate when they see other primates going No. 1 as well, as detailed ...

Yawning—such an odd physiological phenomenon. Humans yawn, and so do dogs, monkeys, birds, and just about every known vertebrate species other than giraffes (yes, that is also odd). Over a decade ago, ...