Monday, September 25, 2006
Social cognition - A 'Current Biology' primer
An open access/free paper from Current Biology:
Current Biology, Vol 16, R786-R790, 19 September 2006
The question of why humans possess superior cognitive skills has a long history in science. One important idea is that human intelligence has evolved in the social realm. The rationale is that individuals who cooperate and compete well in a social setting do better and produce more offspring than less skilled individuals, and that these skills are heritable. The conditions for the evolution of social abilities may have been especially favourable in primates. Most primates live in individualised societies that are characterised by kin-based social networks, a situation that may have triggered an evolutionary arms race in social skills.
Social cognition concerns an individual's ability to interact socially in an intelligent way. As it is near impossible to define intelligence objectively, a common research strategy has been to select a well-described human skill and investigate the degree to which it is present in animal subjects. Episodic memory is a good example. A series of studies with food-caching birds has revealed that these animals are perfectly capable of mentally 'traveling backwards in time' to recollect specific events in the past. Oddly, less evidence for episodic memory has been found in non-human primates, although a study by our group, published recently in Current Biology, has shown that monkeys take past weather conditions into account when searching for food.
One empirical approach to social intelligence is to investigate animals' ability to recognise others' social relations and to predict their behaviour. Research on the formation of social concepts has been particularly important and has revealed some intriguing similarities between human and animal mental abilities. One study, with long-tailed macaques, has become something of a classic. Monkeys were trained to select photographs of familiar group members, either mother-offspring dyads or other pairings. The study animals then successfully mastered novel combinations, demonstrating that they possess a social concept analogous to the human mother-child affiliation. We now know that primates can build up social knowledge from observations alone. After watching video clips of agonistic interactions between two unfamiliar conspecifics, rhesus monkeys were able to select the dominant individual in each interaction, and individuals were able to transfer their skill to novel video clips.
Under field conditions, such complicated techniques cannot be applied, and experimental work typically relies on much simpler paradigms. A successful approach has been to monitor vocal behaviour during social interactions, and to use the observed patterns as a basis for field playback experiments. Subordinate female baboons, for example, tend to produce fear-barks to a more dominant individual approaching them. Dominant females respond with grunts, especially if they desire to interact peacefully. These types of exchanges have successfully been used to mimic different types of social interactions for nearby listeners. In one particularly elegant experiment, baboons not only recognised the rank orders of the different group members, but they also understood to which matrilineal kin group the individuals belonged, demonstrating that primates organise social concepts in a hierarchical way. These and other studies indicate that Sapir's famous proposition that a "concept does not attain to individual and independent life until it has found a distinctive linguistic embodiment" is just not supported by the empirical evidence. [Continued at Citation]