We have chosen to examine the aspects of sexual jealousy from a sociobiological standpoint. This type of jealousy involves a perceived threat to an intimate, committed relationship between two individuals, most often sexually or physically involved. Males have a high food intake for their larger and more energetic bodies. Men also have a much greater amount of testosterone than females. The resulting differences is that men are larger, stronger, and more aggressive.
Paternal investment is the energy expended by parents to produce and nurture offspring.
The mother always knows who her children are, and has a naturally high level of parental confidence. As a result his natural tendencies lean toward aggression and displays of physical prowess. This is to attract desirable mates in order to perpetuate his genes, as well as to protect his mate from other males. It also accounts for the male desire to mate with as many females as possible. As a result the male is very concerned with paternity confidence.