Two typical Facebook profile photos, one American (left), the other East Asian. Images provided by the Center for Vital Longevity/UT Dallas.

Poke around Facebook and you'll see your friends in all sorts of places: at the beach, at a party, at the ballpark, at home.

Our profile pictures can be very different, but two social scientists noticed some patterns.  Compared with people in, say, Taiwan, we Americans show ourselves looming larger in the frame, and smiling more broadly.

This matters, say Chih-Mao Huang of the University of Illinois and Denise Park of the University of Texas at Dallas. They've now published a paper in the International Journal of Psychology, documenting how cultural differences show up online.

"These are not conscious choices," Dr. Park wrote in an email to ABC News. "This represents the lens through which the two cultures view the world.  This relates, we believe, to a cultural bias to be more individualistic in the U.S. and more communal in Asia.  We believe these values fundamentally sculpt one's thought and choices, including design of a Facebook portrait."

Huang and Park say they did two studies of Facebook profile pictures, measuring how people in the U.S. and Taiwan chose to show themselves. They looked at more than 500 pictures in all.

For the most part, they concluded, we all do the same thing: try to put the best foot (or face) forward.  But here's what's different: While 12 percent of Americans posted pictures in which only their heads showed, just one Taiwanese subject (0.9 percent of the sample group) used such a close-up.  The East Asian users tended to prefer wider shots; the backgrounds mattered to them as much as that they were in them.

Similarly, Americans turn up the voltage for their shots.  Fifteen percent more Americans were categorized in the paper as smiling broadly enough that their teeth showed.

What does all this mean?  Huang and Park write of the U.S. as an "individualistic and independent" culture, while people in Taiwan "deemphasize the face and to engage more contextual field information."  Social media - Facebook, in this case - make a giant lab for showing the differences.

Co-author Huang, perhaps knowing people would check, had some fun on his own Facebook page.  His profile photo shows him - from the back, looking up at the psychology building at the university.