Jan. 7, 2011 at 2:28 PM ETWant to look younger this weekend? You might try forming a new posse of old people: Being surrounded by seniors makes you look younger in comparison, world's most obvious study says.MyHealthNewsDaily reports that looking at a series of photos of older people -- and then looking at a photo of a 30-something face -- makes us think that 30-year-old is much younger than he or she is, according to German researchers, who published their findings in the Nov. 23 of the journal Vision Research. The researchers asked 24 young adults to look at pictures of 15 female and 15 male faces. Each image was doctored to show what the person would look like in his or her 20s, 30s, 40s, 50s, 60s and 70s.The volunteer were systematically wrong at estimating other people's ages after they had looked intensely at faces of people of a specific age group.For example, if many faces of elderly people were shown on the computer first, followed by the face of a middle-age person, the volunteers made out the middle-age person to be substantially younger than he or she was. But after first studying younger faces, the volunteers estimated the middle-age person as being substantially older. But stay away from crowds of young'uns, because the opposite is true, too -- after looking at photos of younger people, the study participants judged the face of the 30-something person to be older. Turns out, we're pretty good at determining the age of the person next to us, but it all falls apart when we see a bunch of similar-aged faces in succession. Find The Body Odd on Twitter and on Facebook.