Evolutionary psychology is a cognitive approach to social behaviors which considers the mind as the result of adaptation of human beings with ecological and social necessities of itself and is trying to understand the evolutionary function of human behaviors including his aggressive behaviors. This cognitive approach has a combinational method. A method that considers the human being behaviors as the result of interactions between inherent and environmental factors during thousands of years and describes that the reasons and procedure of creation of behavior can be identified by studying cognitive structure in human being which has several symptoms of the past of this creature with itself. Evolutionary psychology instead of identifying aggressive behaviors such as homicide as abnormality is searching for an answer to the reason of creation of psychological preliminaries of such behaviors in human being ancestral environment and it has significant responses for describing the fixed patterns of diagrams related to homicide. Patterns that indicate homicide is usually committed by young males that are deprived from legal social and economic opportunities. This approach, considering its focus on sex and age as determinative factors in human being growth can provide appropriate criminological hypotheses for justifying the aggressive behaviors of human being. The present paper expresses and describes the procedure of homicide in a descriptive and analytic way and with regard to existing researches by evolutionary psychology.
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