Love?
Studies show that men tend to fall in love quicker than women do, as an evolutionary adaptation.
Love is actually a method for showing commitment to women since women are skeptical of men’s commitment, thus, in order to reduce this skepticism, men display love (defined as: “A very powerful emotional experience that might include excitement and anxiety, tender feelings and physical attraction toward a particular person, constant thoughts of the person, and an intense desire to be around the person”) typically earlier than the woman of the relationship does.
However, women with stronger sex drives tend to fall in love quicker than their females companions, while sex drive does not affect men’s rate of falling in love.