A new study confirms that people, like many animals, easily recognize a unique—but not unpleasant—eau de elderly. The unique scent of the elderly lingers wherever they live and in any confined spaces they have recently occupied, such as taxis and elevators. Many different cultures have recognized the phenomenon—the Japanese even have a word for it, kareishuu—but the biological truth of old person smell remains uncertain. In a new study, blindfolded volunteers reliably recognized the aroma of the elderly by sniffing sweat-soaked armpit pads, although they had a much harder time correctly matching pads to the young and middle-aged, and they were not able to make fine distinctions about age based on scent alone. Contrary to the popular notion that old person smell is disagreeable, volunteers in the new study rated the odors of the elderly as much less unpleasant and intense than those of the middle-aged and young. Combined with earlier research, the new findings suggest that people retain a latent ability to gauge someone's age based on their odor, a talent inherited from evolutionary ancestors that might be linked to the ways animals recognize the sick and dying.