<p>Robert Provine boldly goes where other scientists seldom tread—in search of hiccups, coughs, yawns, sneezes, and other lowly, undignified human behaviors. Upon investigation, these instinctive acts bear the imprint of our evolutionary origins and can be uniquely valuable tools for understanding how the human brain works and what makes us different from other species.</p><p>Many activities showcased in <i>Curious Behavior</i> are contagious, but none surpasses yawning in this regard—just reading the word can make one succumb. Though we often take it as a sign of sleepiness or boredom, yawning holds clues to the development of our sociality and ability to empathize with others. Its inescapable transmission reminds us that we are sometimes unaware, neurologically programmed beasts of the herd. Other neglected behaviors yield similar revelations. Tickling, we learn, may be the key to programming personhood into robots. Coughing comes in musical, medical, and social varieties. Farting and belching have import for the evolution of human speech. And prenatal behavior is offered as the strangest exhibit of all, defying postnatal logic in every way. Our earthiest acts define <i>Homo sapiens</i> as much as language, bipedalism, tool use, and other more studied characteristics.</p><p>As Provine guides us through peculiarities right under our noses, he beckons us to follow with self-experiments: tickling our own feet, keeping a log of when we laugh, and attempting to suppress yawns and sneezes. Such humble investigations provide fodder for grade school science projects as well as doctoral dissertations. Small Science can yield big rewards.</p>