Every year around 1 billion Valentine cards are sent. After Christmas it's a single largest seasonal card-sending occasion.
14
Couples' personalities converge over time to make partners more and more similar.
235
Ten seconds of hugging a day increases levels of oxytocin, which can reduce blood pressure, thus cutting the risk of heart disease.
26
Two in five people in the world marry their first love.
270
Men who kiss their wives in the morning live five years longer than those who don't.
1k
Wearing red increases attraction.
30
In 2011, archaeologists discovered the skeletal remains of a Roman couple who have been holding hands for 1,500 years.
81
The left ear is more responsive to words of love and emotion whispered into it than the right.
44