Apparently around 150,000 photos are added to Facebook every minute, and their $1bn purchase of Instagram is likely to ensure that photos remain central to the Facebook experience.  I wrote earlier this year on how your profile photo can affect how outgoing people perceive you to be.

The kind of photo you use however could be influenced by your cultural ancestry.  That's the finding of new research by psychologists in the USA.

The researchers analysed the profile photos of American citizens and those of Taiwanese citizens and found distinct differences between the two groups.  Facebook users originally hailing from Taiwan were more likely to have a zoomed-out picture in which they were seen against a background context. Users from the USA, by contrast, were more likely to have a close-up picture in which their face filled up more of the frame.

This style was also shown to be influenced by the users current location.  For instance Americans living in Taiwan used a more Taiwanese style, and vice versa.

The findings were replicated in a second study of students at American and Asian universities.  In this, like the first, American students focused mainly on their face in their profile photo, whilst Asian students were more likely to reveal more background context.

"We believe this may be the first demonstration that culture influences self-presentation on Facebook, the most popular worldwide online social network site," the researchers said.

The new findings complement an existing literature showing cultural associations with attentional and aesthetic habits. For example, a 2008 study (pdf) showed that portrait photographs taken by East Asians tended to show more background (and that participants from that culture preferred pictures of that style), whilst those taken by Westerners were more focused on the target's face (and Americans said they preferred that style). Similarly, eye-movement research has shown that Westerners looking at a scene tend to focus more on embedded central objects, whilst Chinese look more often at the background.

"Our findings further extend previous evidence of systematic cultural differences in the offline world to cyberspace, supporting the extended real-life hypothesis," the researchers said, "which suggests that individuals express and communicate their self-representation at online social network sites as a product of extended social cognitions and behaviours."