Science explains why we're constantly tempted to check Facebook!

If you've ever felt the obsessive need to check Facebook - usually while you're putting off working or doing something productive - then you'll be interested in the findings of a new study from the University of California, Los Angeles. Researchers have found that our brains have an in-built need to be social, and Facebook scratches that mental itch.

The team of UCLA neuroscientists discovered that even during quiet moments, our brains are preparing to be socially connected to other people, craving the next like, timeline post or message. "The brain has a major system that seems predisposed to get us ready to be social in our spare moments," Matthew Lieberman, who headed up the research, said in a press release. "The social nature of our brains is biologically based."

The new study builds on discoveries made in the 1990s: that there are regions of the brain that become more active when we're resting. Until now, scientists have known little about what that brain activity is or what it's leading to - but it appears our innate need to interact with others is at the centre of it, our need to "see the world through a social lens" in the words of the study (sounds like Facebook to us).

By tracking the brain activity of 21 volunteers using functional magnetic resonance imaging (fMRI), researchers found a link between the brain activity when resting and when looking at a series of images and captions that made them think about other people's emotions. These activity patterns disappeared when participants were asked to focus on a maths problem or to think about more physical topics.

It appears that during our downtime, the brain switches on the dorsomedial prefrontal cortex to prepare for social engagement. Subsequent engagements are then faster and more fluid because we're prepared for them - Lieberman calls the dorsomedial prefrontal cortex the "CEO of the social brain" and it's also active when we're dreaming.

"[This part of the brain is] getting us ready to see the world socially in terms of other people's thoughts, feelings and goals," adds Lieberman. "That indicates it is important; the brain doesn't just turn systems on. We walk around with our brain trying to reset itself to start thinking about other minds."

Which brings us back to Facebook: it would seem that the social network Mark Zuckerberg created is built to fit the natural rhythms of the brain, which may explain why more than a billion people have signed up to use it.

"When I want to take a break from work, the brain network that comes on is the same network we use when we're looking through our Facebook timeline and seeing what our friends are up to," explains Lieberman. "That's what our brain wants to do, especially when we take a break from work that requires other brain networks."