The jealousy response also tends to be different in nature between the sexes.

Jealousy warns a woman that she is vulnerable to losing the resources (and the signals like love, attention, time and sexual desire that are her practical measure). Males require the same warnings from the instincts (to a lesser degree for a slightly different reason). But on top of that males must be warned that their huge investment of resources may be vulnerable to being utterly wasted when another male impregnates their investment. There is a stronger evolutionary motive for territorial instincts to assert themselves.