1. Another vigorously debated issue is whether language is uniquely human. Animals obviously communicate. Bees, for example, communicate the location of food through an intricate dance. And several teams of psychologists have taught various species of apes, including a number of chimpanzees, to communicate with humans by signing or by pushing buttons wired to a computer. Apes have developed considerable vocabularies. They string words together to express meaning and to make and follow requests. Skeptics point out important differences between apes’ and humans’ facilities with language, especially in their respective abilities to order words using proper syntax. Nevertheless, these studies reveal that apes have considerable cognitive ability.