Nonhuman primates, for example, do not have the same level of mental thinking as humans. Having less mental thinking, they do not find it necessary to communicate apart from alarm calls. Nonhuman primates also resulted in an undeveloped language system for communicating, in contrast to humans, by their unspecialized vocal cords. Their vocal cords are not as flexible and complex as humans’ thus they cannot produce richer, more flexible variable sounds. For example, humans have acoustic strings that help in making various changes in tone (Zuberbuhler
