The social environment is highly relevant to the evolution of human communication capabilities. Human communication evolved through primates living in groups. Living in groups creates opportunities for synchronized physiological states, cooperative predator defense, coordinated food acquisition, diffusion and inheritance of behavioral innovations, and exchange of goods such as food, sexual activity, and grooming. Living in groups also creates opportunities for individual and coalitional action to shift the distribution of food, mating, and physical risks among group members. Communication capabilities have evolutionary significance both for cooperation and competition within social groups.
Relative to other animals, humans have greater social complexity and engage in more complex communication. Consider, for comparison, humpback whales. Humpback whales work together in role-differentiated teams to feed upon schools of fish. Male humpback whales also engage in behaviorally elaborate mating competition that includes complex vocalizations (songs). The coding bandwidth required to communicate a male humpback whale song, however, is roughly fifty times less than the coding bandwidth required to communicate spoken English. Many organisms are social and communicate with each other in a variety of forms. Humans form intricate social groups and communicate with each other vocally at a much higher coding complexity per unit time than do other animals.
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- vocal repertoire size positively correlated with social group size
- sex differences in communication among razorbills
- Barbara the chimpanzee learns to mother
 Mitani (2006) describes the importance of differences in group demographics for differences in chimpanzee behavior. He notes that demographic context has often been overlooked as a cause of intraspecific behavioral variation. Laskowski & Pruitt (2014) recently established the importance of group demographics for spider personality.
 Such behavior is called bubble-net fishing.
 For a review of knowledge about humpback whale song, see Parsons, Wright & Gore (2008).
 Humpback whales on the Hawaiian breeding ground communicate in song at 0.6 bits/unit, with 2.5 seconds/unit, giving 0.24 bits/second. Suzuki (2006) pp. 1860, 1862. Australian humpback whales migrating away from their breeding ground had coding bandwidth about a third less than the Hawaiian whales. Miksis-Olds et al. (2008) p. 2391. I calculate the bandwidth of spoken English as 69 bits/second, based on 1 bit/letter, 5 letters/word, and 200 words per minute. These figures should be understood as rough approximations.
[image] 15 humpback whales bubble-net fishing off the coast of Alaska on 18 August 2007. Thanks to Evadb and Wikipedia.
Laskowski Kate L., and Jonathan N. Pruitt. 2014. “Evidence of social niche construction: persistent and repeated social interactions generate stronger personalities in a social spider.” Proceedings. Biological Sciences / The Royal Society. 281 (1783).
Miksis-Olds Jennifer L., John R. Buck, Michael J. Noad, Douglas H. Cato, and M. Dale Stokes. 2008. “Information theory analysis of Australian humpback whale song.” The Journal of the Acoustical Society of America. 124 (4): 2385-93.
Mitani, John C. 2006. “Demographic influences on the behavior of chimpanzees.” Primates 47: 6-13.
Parsons, E.C.M., A.J. Wright, and M.A. Gore. 2008. “The Nature of Humpback Whale (Megaptera novaeangliae) Song.” Journal of Marine Animals and Their Ecology 1 (1): 21-30.
Suzuki, Ryuji, John R. Buck and Peter L. Tyack. 2006. “Information entropy of humpback whale song.” Journal of the Acoustical Society of America 119(3): 1849-1866.