To use an evolutionary perspective is to consider all behaviors (such as fears, prejudices, relationships, etc.) as the result of evolutionary processes. This perspective takes the stance that behaviors came into existence as a result of adaptations to living conditions.
For example, humans naturally dislike and fear spiders and snakes. Using an evolutionary perspective, this is because our ancestors learned that these creatures are frequently poisonous and may be deadly. Likewise, humans have a natural fear of large carnivorous animals and know instinctively to stay away from them. The humans who developed a fear for these creatures were evolutionarily more successful because they avoided these harmful organisms and more of them survived than their counterparts who did not learn to fear harmful animals.