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
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
In 2012, a Chinese man named Xiao Fan had a dress made out of 9,999 red roses for his girlfriend and then proposed - 9 in China means forever
16
One in five long-term love relationships began with one or both partners being involved with others.
177
In Finland, Valentine's Day is called "Ystävänpäivä" which translates into "Friend's day".
4
In 2011, archaeologists discovered the skeletal remains of a Roman couple who have been holding hands for 1,500 years.
81
Couples' personalities converge over time to make partners more and more similar.
235