Two billion people use Facebook every month for an average of 35 minutes each day, but has anyone actually stopped to ask why?

That was the mission statement of a team of researchers from Brigham Young University, Utah, who discovered there are just four categories of Facebook users – Relationship Builder, Tower Crier, Selfie and Window Shopper.

To help you work out which category you fit into, here is a description of each, as stated by the university's own research.

Relationship Builder - You post, respond to others' posts and use additional Facebook features primarily in an attempt to fortify relationships that exist beyond your virtual world. Lead author Tom Robinson says these people use Facebook "as an extension of their real life, with their family and real-life friends." Relationship builders agree with the statement "Facebook helps me express love to my family and lets my family express love to me."

Town Crier - You have a much larger gap between your real and virtual worlds. Unconcerned with sharing photos, stories or other information about yourself, town criers instead "want to inform everybody about what's going on...they're pushing out information," Robinson said. These people report news stories and announce events, but "may otherwise neglect their profile pages, preferring to update family and friends through alternative means."

Selfie - You use Facebook to promote yourself. Like relationship builders, selfies post pictures, video and status updates, but instead this frequent posting is focused on getting attention, likes and comments. Study participants described as selfies identify highly with the statement "The more 'like' notification alarms I receive, the more I feel approved by my peers". Study co-author Kris Boyle said selfies use Facebook "to present an image of themselves, whether it's accurate or not."

Window Shopper - Like town criers, you feel a sense of social obligation to be on Facebook but rarely post personal information. Co-author Clark Callahan said these users "want to see what other people are doing. It's like the social media equivalent of people watching." Window shoppers identified with the statement "I can freely look at the Facebook profile of someone I have a crush on and know their interests and relationship status."

Which of these four categories of Facebook user sounds most like you? Take part in the survey below to let us know and find out how popular your category is compared to the others.

Although previous studies into behaviour among Facebook users unearthed the relationship-builder and selfie categories, Robinson says the town crier and window shopper categories were an unexpected find. "Nobody had really talked about these users before, but when we thought about it, they both made a lot of sense," he said.

Boyle concluded: "Social media is so ingrained in everything we do right now, and most people don't think about why they do it, but if people can recognise their habits, that at least creates awareness."