The adaptive nature of memory

The rational analysis of memory proposes that much of human memory performance can be understood as an adaptive response to the demands the environment makes on memory. Reliable relationships exist between the availability of human memories for specific items and prior experience with the items, such as how recently and frequently they have been encountered and in what contexts. Analyses of a number of environmental sources, such as a diary study of social contacts and word usage in speech to children, show that the probability of being in contact with a person or a word shows reliable relationships with the recency, frequency, and context of past contact. The close correspondence between these environmental functions and memory performance supports the claim that human memory takes the form it does because it is adapted to these kinds of environmental relationships. An analysis of chimpanzee social contacts and retention functions raises the possibility that the same claim may hold for that species as well.