Couples' personalities converge over time to make partners more and more similar.
235
Every year around 1 billion Valentine cards are sent. After Christmas it's a single largest seasonal card-sending occasion.
14
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
Men who kiss their wives in the morning live five years longer than those who don't.
1k
Wearing red increases attraction.
30
Historically, sweat has been an active ingredient in perfume and love potions.
309
40% of people who are rejected in romantic love slip into clinical depression.
72