Every once in a while in Machakos, a story airs about a lover that ended up killing their partner in a fit of rage. Almost immediately, people start remarking how stupid such an act is, and forget how they themselves behave while in the throes of love.
Psychologists, especially doctor Ellen Berscheid and Elaine Walster have tried to analyze this behavior, together with violence in relationships and the findings are shocking, to say the least.
They attribute such reckless behavior to the pressures felt in intimate relationships. For example, male partners experience paternity pressures, which means that sexual competition, and the costs of rearing a child fathered by another man, are assumed to be strong selection pressures that have influenced the evolution of psychological processes and structures.
This is extreme Darwinism and one would understand why for a man, the one thing that hurts him most is the infidelity of his partner.
This has led many a man to commit murder. Women are also possessive of their male mates, and should be powerfully motivated to hold on to their male partners to help raise the children.
The difference between the genders is that men are more focused on the sexual aspects than are women.
Thus, men suffer from sexual jealousy primarily as a response to their partners having sex with another person, whereas women are more psychologically attuned to the threat of losing the relationship.
None of this is a cogent argument for committing harm to another person. Such feelings of extreme narcissism are symptoms of underlying obsession and possessiveness and should be revealed to a trusted and trained professional.