Language serves to enhance group cohesiveness among social animals. Honeybees use symbolic gestures in the form of dances that communicate the direction and distance the other bees must fly to reach food sources or other things of interest. Birds, ground squirrels, and some nonhuman primates have different alarm calls that are recognized by other members of their species even when a predator is not present. A recent study of finch calls found that the birds' calls, like human language, followed "strict rules of syntax."** The vocalizations of crows and ravens also share many of the properties of human language.

Like humans, these animals understand the relationship between the signals they use and the events these signals refer to. They are not simply expressing an emotion or communicating about something that is only in the moment. They are actually using symbolic language to refer to things in the outside worldthings that do not need to be immediately present for them to understand what is being communicated. Many animalsincluding apes, chimps, dolphins, dogs, and parrotscan also understand several words in human languages and respond to commands containing strings of words. The gorilla Koko, for example, had a vocabulary of more than ..... human words. The border collie Chaser also had a vocabulary of more than ... words.

1. Humans also use nonverbal communication, such as dance. Give examples of ways in which you use nonverbal language such as dance or gestures to communicate information and serve the other three functions of language.
2. Discuss how barriers to critical thinking such as narrow-mindedness can prevent us from seeing the use of language by other animals as well as keep us from appreciating the richness and diversity of languages of other cultures.