1. When you kiss someone for the first time, you get a spike in the neurotransmitter dopamine, making you crave more.
2. Dopamine can also make you lose your appetite and make it hard for you to sleep.
(Among the many other things it does for us).
3. Two thirds of people tilt their head to the right when they kiss.
German researcher Onur Güntürkün discovered this after spying on 224 couples kissing in public places in the United States, Germany and Turkey.
4. Kissing helps us work out if someone is a good match.
According to biological anthropologist Helen Fisher, we tend to prefer people with particular biological profiles. Trading saliva is one way to figure out if someone is a good fit.
5. When you kiss someone your heart beats faster and more oxygen reaches your brain.
All thanks to neurotransmitters epinephrine and norepinephrine which promote the fight-or-flight response.
6. And it makes your pupils dilate.
Which might be why we usually close our eyes.
7. Endorphins released during kissing bring on waves of euphoria.
You can thank your pituitary gland and hypothalamus for this natural high.
8. The muscle you use to pucker your lips is called the “orbicularis oris”.
And the shape you make with your mouth mirrors that of a breastfeeding baby, hinting at one possible way that kissing evolved.
9. Nachküssen is a German word that means “a kiss to make up for those that have not occurred”.
10. Kissing triggers the release of oxytocin in your body.
Often called the “love hormone”, though that’s not all it does by a long stretch, oxytocin is involved in developing feelings of attachment. It’s thought to be what keeps the love in a relationship alive long after the initial honeymoon period (and dopamine spike) is over.
11. More kissing in a relationship is related to how satisfied people say they are in that relationship.
The same study found that this wasn’t the case for having more sex. But people’s satisfaction with the amount of kissing and sex was related to the quality of their relationship.
12. Women tend to rate kissing as more important in relationships than men do.
The study, involving more than 1000 college students, also found that whereas women tend to use kissing to assess potential mates, men use it to increase the likelihood of sex.
13. The world record for the longest kiss stands at well over two days.
It’s held by Thai couple Ekkachai Tiranarat and Laksana Tiranarat who set it in the run up to Valentine’s day last year, with a kiss lasting 58 hours, 35 minutes and 58 seconds.
14. Your lips have a disproportionate number of nerve endings compared to other parts of your body.
As demonstrated on something known as the “cortical homunculus”.
15. When your lips touch someone else’s 5 out of 12 of your cranial nerves are engaged.
You’re brain is basically trying to gather as much information as it can about the other person.
16. Over time, kissing lowers your levels of stress hormone cortisol, making you feel all safe and secure.
The longer you’ve been with someone, the bigger the decline.
17. Most people remember their first kiss more vividly than the first time they had sex.
John Bohannon of Butler University asked 500 people about their memories of important life experiences, including their first kiss and losing their virginity. The kiss beat everything as the most detailed memory.
Additional source: The Science of Kissing by Sheril Kirshenbaum.