Couples' personalities converge over time to make partners more and more similar.
235
Sandy, an African Penguin, has been in 'love' with her keeper at the Nuremburg zoo since 1996.
34
A man's beard grows fastest when he anticipates sex.
239
Parents receive 1 out of every 5 Valentines.
20
Every year around 1 billion Valentine cards are sent. After Christmas it's a single largest seasonal card-sending occasion.
14
Falling in love raises levels of nerve growth in a person's brain for about a year and can improve their memory.
39
Approximately 141 million Valentine's Day cards are exchanged worldwide every year.
104