I think the S+ group equates to those who look like they'll screw on the first date, and the S- those who won't.
Amusing that the photos are all of women who are easy on the eye. Would have been a far better test if some of the photos had been of the "only with beer goggles" or "not even with your barge pole" variety.
An even better test would have been to get the Chinese students to try to assess faces they're not familiar with - a bunch of white women maybe, or black africans. To take it even further, it would be interesting to see how the effect of alcohol affects the judgement: make them reassess the same girls while drunk
