Chances are you spent a long time selecting your Facebook profile picture but why did you choose it?
An investigation into the psychology of profile pictures for the BBC Radio 4 So You Want to Be a Scientist? project discovered that different demographics display diverse photos.
The research revealed that males were 50 per cent more likely to have altered their photo compared to women but were 20 per cent less likely to be smiling.
People who showed themselves with their partner had a 35 per cent increased chance of smiling, while those under 30 were twice as likely to be shown at a party.
Dr Bernie Hogan, of Oxford University's Internet Institute, told the BBC News: "Facebook is becoming one of the de facto ways that we present ourselves to friends and family.
"This photo has become the new calling card, the first point of contact, so (it) is important for understanding what it is we want to show off to each other online."
If you constantly check Facebook and regularly update your status then chances are you could have narcissistic tendencies.
That is the scientific opinion of researcher Soraya Mehdizadeh who asked 100 students aged between 18 and 25 about their Facebook habits and concluded that regular use of the social networking site can lead to narcissism.
Miss Mehdizadeh, of York University in Canada, admitted that the majority of people would disagree with her controversial findings.
She said: "I think people get sort of defensive about it - like, 'I don't use my Facebook for that reason' - because it's a label that you don't want to be slapped with."
The study also found that men placed more value on written profile entries, while women were more interested in which pictures appeared on their personal page.
Research by comScore revealed that Americans are spending more of their web time socialising on Facebook than searching with Google.
Last month, Americans spent a total of 41.1 million minutes on Facebook compared to 39.8 million minutes with the search engine giant.
People who regularly use social networking sites are more likely to be happier than those who shun Facebook and Twitter.
A report by the Chartered Institute for IT, BCS entitled "The Information Dividend: Why IT makes you happier" argues that social networking sites have a positive impact on society.
The Social Network, the film about the rise of Facebook and its founder Mark Zuckerburg opens across UK cinema on October 15th.