Sexual Jealousy

• Unlike women, men cannot be sure if they are truly the biological fathers of their offspring. This is called paternity uncertainty.
• Paternity uncertainty mean there is a risk of cuckholding (raising a child that's not biologically yours).
• Since cuckholding involves investment of resources (time, food, energy) in offspring that do not share a male's genes, this contributes to the survival of a rival male's genes, and leaves the father with less resources to invest in his own offspring.
• Men who avoided cuckholding were more reproductively successful and ensured better survival of their genes.
• Psychological mechanisms like sexual jealousy and possessive behaviours are helpful to avoid cuckholding and improve chances of passing on genes. This leads to males using aggressive strategies to retain their partners and prevent infidelity.