Atelier Persol, Firenze
Philematology is the science that examines kissing from a biological perspective.
The main purpose of kisses is sharing germs and developing antibodies, self-reinforcing and preserving offspring.
Men tend to consider kiss as a prelude for sexual activity and prefer kisses with saliva in order to share testosterone with their partner.
Kiss can also cause a variation in cortisolo and oxytocin blood level. After the kiss, cortisolo decrease for both sexes reducing stress, while oxytocin levels increase only for male.