From an evolutionary perspective, jealousy has solved a problem of reproduction: throughout human history, jealousy has ensured reproductive success.
With regard to solving the problem of reproduction, men and women seem to differ because they get jealous in different ways due to their respective adaptive problem (Sagarin et al., 2012).
Women get jealous because of emotional infidelity, whereas men get jealous because of sexual infidelity. The explanation for this is that women need to be sure that the man provides paternal investment to their child, and men need to be sure that it is their biological child that they use their resources for.
Therefore, men get jealous because of their mate’s sexual infidelity, since they cannot be sure whether it is their child or not, and women get jealous because of emotional infidelity since this type of infidelity hinders the man from ensuring a proper paternity.
An aspect of this theory is that a man’s sexual infidelity does not burden his mate with a non-biological child, and therefore, women more often get jealous of emotional infidelity instead of sexual infidelity.
A meta-analysis by Sagarin and colleagues (2012) examined 47 independent samples, including 209 effect sizes. On the basis of their exhaustive meta-analysis, they concluded that gender differences in jealousy do exist, and that the findings are stable, valid and reliable.
Furthermore, the theory of jealousy is not a theory of evolved gender differences in anger, disgust, distress or upset. Jealousy seems to be an unique emotion among other negative emotions. In their study, they found that the gender differences exist even across cultures, which supports the idea of an evolutionary theory of jealousy.
Schützwohl (2006) proposes that men and women differ in the way they cognitively extract information from the environment with regard to infidelity. Women are more occupied with thoughts about emotional unfaithfulness, whereas men are mentally occupied with the sexual unfaithfulness of their partners.
Does this sound familiar to you?