evolutionary influences

• this assumption is based on Darwin's theory of natural selection - any genetically determined behavior that will enhance an individual's chance of survival and reproduction will be naturally selected and passed on to the next generation.
• a special type of natural selection is sexual selection - this theory suggests that the characteristics of an animal that increase mating success are more likely to result in reproduction, passing that characteristic onto offspring.
• environment of evolutionary adaptiveness (EEA.) The human species evolved large brains to deal with the complex social organisations required in our EEA - those better at forming alliances would have had greater survival chances.
• EXAMPLE

  Trivers claimed that the formation of romantic relationships is driven by evolution, specifically how each sex has a different level of investment in ensuring their offspring survives in order to pass on their family genes.