When a male gentoo penguin "falls in love" with a female penguin, he searches the entire beach to find the perfect pebble to present to her.
25
In medieval Italy, if a man was caught kissing a woman in public, he had to marry her whether he liked it or not.
456
Brain scans show that people who view photos of a beloved experience an activation of the caudate - the part of the brain involving cravings.
103
According to the New York Times, a study conducted during the 1980's found that men who kiss their wives before leaving for work live longer, get into fewer car accidents, and have a higher income than married men who don't.
14
In Korea, if you do not receive any gift on Valentine's day then all the singles go to Korean restaurants and eat black noodles to celebrate (or mourn) their single status.
27
Couples' personalities converge over time to make partners more and more similar.
235
In 2011, archaeologists discovered the skeletal remains of a Roman couple who have been holding hands for 1,500 years.
81
It's possible to die from a broken heart; it's called Stress Cardiomyopathy.
165