Why Do Humans Kiss

Two theories for why humans have a need to kiss stem from the idea that as babies we have an innate liking for lip touching. In one case, it might be that we associate lip touching with... MATILDA BRINDLE: I think the key here is that kissing seems like a very unhygienic and vulnerable thing to do, particularly if it's a kind of sloppy kiss and there's a lot of tongue going on.

Kissing is something very few species do. Why is that, and why do we do it? Learn more about this evolutionarily unique romantic activity. Kissing is a complex behavior that can have different meanings and effects depending on the context and the person.

Learn how kissing triggers hormones, nerve endings, and emotions, and how it can strengthen bonds, increase arousal, and feel good. Humans kiss for a combination of reasons rooted in biology, bonding chemistry, and sensory wiring. No single explanation covers it fully.

Kissing triggers a cascade of hormones that strengthen attachment, delivers sensory information about a potential partner, and even exchanges millions of bacteria that may prime the immune system. Looking at the big picture, there are two main hypotheses about why we kiss: either its a learned behaviour, or its instinct. Back to the evolutionary biologists.

Kissing feels natural, but why do we do it? Science points to evolution, brain chemistry, and mate assessment as the real reasons behind this surprisingly complex behavior. OK, so you found out in your research - by tracing the phylogenetic tree of kissing through primates, you found out that kissing was likely present in the ancestor of all apes who lived 21 million years ago. Kissing can release endorphins that make you feel good and bond with your partner.

It can also reduce stress, increase life satisfaction, and improve your relationship quality. Learn more about the purposes and benefits of kissing from PsychCentral. Evolutionary biologist Matilda Brindle tells us the sordid details driving this behavior, what distinguishes different kinds of kissing and whether culture has anything to do with why people...