Regardless of its name— kissing, making out, tonsil hockey— locking lips is something we’re all pretty familiar with. But has anyone stopped to think about why we do it? Where does that urge come from to plant a big wet one on a significant other (or whomever else found themselves in front of those lips last night)? Kissing of closeness, sexual excitement, happiness, and even motivation (go get em’ tiger!).

Pucker up, Buttercup — The Need to Know

Kissing, in some form or another, has been going on for . The first literary evidence of kissing (or something like it) came from ancient Sanskrit texts. While there are several reasons to kiss, romantic kissing has its motivation rooted in biology. Researchers believe we kiss romantically to , stay committed to that person, and to reproduce. When we kiss another person, neurotransmitters in our brain release dopamine, triggering . Serotonin levels also spike, creating obsessive thoughts about partners, as do levels of oxytocin (aka the “love hormone”), eliciting a feeling of bonding and attachment. And one study suggests all this brain action occurs to focus our biological attention on one person (essentially, a potential mate to reproduce with) and stops us from spending too much time and energy elsewhere (isn’t that sweet?) Fisher H.E., Aron A., Brown LL., Department of Anthropology, Rutgers University, 131 George Street, New Brunswick, NJ, Philosophical Transactions of the  Royal Society of London Series B. Biological Scientists, 2006 Dec 29;361(1476):2173-86..

As most of us know, not every kiss is going to end with marriage and children (and lets give thanks for that!). A whopping say they have ended a budding relationship because of a kiss (even more incentive to double check that breath). Another study showed that men were more likely to initiate kissing prior to doing the deed, while women were more likely to steal kisses after Hughes S.M., Kruger D.J., Department of Psychology, Albright College, Reading, PA. Journal of Sex Reseearch, 2011 Sep;48(5):496-505. Epub 2011 May 24.. But both genders believed kissing before sexual intercourse with a long-term partner was important (with cuddling and saying "I love you" being the most important after sex) Hughes S.M., Kruger D.J., Department of Psychology, Albright College, Reading, PA. Journal of Sex Reseearch, 2011 Sep;48(5):496-505. Epub 2011 May 24..

Eskimo Kisses — Your Action Plan

While finding (and keeping) a perfect match may be our motivation to kiss, there are some pretty nice health benefits as well. Kissing can , is a natural relaxant, and also (what more could we want?). Surprisingly enough, another study showed that frequent kissing, cuddling, and hugging is a significant factor in happiness for men in long term relationships— even more than for the ladies!

But think twice before planting a wet one on just any guy or girl: Swapping spit means sharing with someone. (Gross, we know.) If that’s not uncomfortable enough, infections like (aka mono) or herpes can be spread by even the most innocent of lip locks. One study suggested an increase in sexual expression, including kissing, is a common factor in the oral transmission of the HPV virus . Louis Z.G. Touyz, BDS MSc(Dent) MDent(Perio&OralMed), Faculty of Dentistry, McGill University, Montreal, QC. Current Oncology, 2011 August; 18(4): 167–168.. People with severe food or medication allergies are even when kissing, so be aware of what's on those lips before puckering up!

Do you think the science tells it all when it comes to kissing? Disagree? Tell us in the comments below!