'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
When someone looks at a new love, the neural circuits that are usually associated with social judgment are suppressed.
130
Two in five people in the world marry their first love.
270
Erotomania is a type of delusion in which the person believes another person is in love with him/her.
38
In 2011, archaeologists discovered the skeletal remains of a Roman couple who have been holding hands for 1,500 years.
81
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
A man's beard grows fastest when he anticipates sex.
239
Couples' personalities converge over time to make partners more and more similar.
235