A study suggests yawns are twice as contagious in women as they are in men.

Researchers at the University of Pisa say the finding can be explained by the fact that women are the more empathic sex.

After observing 1461 yawning bouts in everyday situations over a period of five years, a team of researchers concluded that women were roughly twice as likely to "catch" a yawn as men.

Yawn contagion rates were also found to be significantly lower between acquaintances than between friends and relations.