As a result a person develops behavioral strategies to solve different problems that are set by nature like arranging for food, mating, looking after the offspring and maintaining interactions with kin, offspring and other individual.
HBE gained popularity between 1960s and the 1970s when there was growing emphasis on animal behavior and evolutionary biology. J.B.S Haldane a British evolutionary biologist by 1956 had already argued that differences of human behavior could be analyzed as responses of different individuals with similar genetic composition exposed to varying environments. But the initial developments of HBE were in the field of foraging, drawn for the optimal foraging theory (OFT). This was because OFT was sophisticated and testable theory by 1980s and because much of the history of human species was spent as foragers. Foragers offer experiments for studying human behavioral variability. If people of today forage for living are constrained by aspects of ecology, then the variations in these limitations, the difficulties imposed by these constraints and the solutions that different individuals adopt to overcome the constraints are open to ethnographic observations. The OFT consists of a groups of models addressing resource choice, time allocation and patch choice and diet breadth model that is most commonly used in studying humans. In accordance to this model, individual foragers select food resources that promise to provide maximum nutrition, by trading off the handling and search times associated with acquiring that food source. Foragers often bypass those food sources that yield low post encounter mean rate of nutrition when more profitable food sources are common, but they take a broader array of prey species when more profitable items are rare (Kaplan and Hill, 167-201). Changes in subsistence pattern over a period time can be explained by changes in response to factors like technology, climate changes and availability of foreign imports. Thus new technology can either expand or contract the diet breadth (prey choice), depending on whether the cost of searching and handling the food resources have been affected. The diet breadth models even deals with archaeological deposits. For instance, deposits associated with societies that are on the brink of adopting agricultural activities, show increasing exploitation of previously unused sources, like plant food and seeds that require extensive processing. The diet breadth model as such suggests that agriculture emerged many times in history as an alternative in response to decrease in encounter rate with higher ranked nutritional items.
Failures to support the foraging model predictions have been just as intriguing as the successes. For instance despite what foraging model suggest that humans acquire food that maximizes their mean acquisition, men go for large preys like animals, ignoring the small food items like plants that are more profitable for increasing their mean acquisition rate. Women on the other hand frequently do the opposite and favor small food items over large preys like animals. These observations have helped in generating two alternative hypotheses. The first hypotheses relates to the differences of constraints, that men maximize their nutritional acquisition through paying attention to the currency that gives more weightage to protein rather than