'X' became symbolic for a kiss because in the middle ages when alot of people were illiterate and they used to sign documents with an X and then kiss it for sincerity.
255
Wearing red increases attraction.
30
Kissing releases masses of oxytocin, a "love potion" that helps couples bond and feel more attracted to each other.
13
Men fall in love faster than women do.
32
Studies show that the risk of a “secret love” being revealed heightens romantic feelings for the partners, thanks to increased levels of phenylethylamine (PEA).
99
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
Couples' personalities converge over time to make partners more and more similar.
235
Approximately 141 million Valentine's Day cards are exchanged worldwide every year.
104