http://www.communicationcache.com/uploads/1/0/8/8/10887248/p...
From that, here's the actual paper. Little methodology description, no significance testing, no indication of the number of participants or how they were selected. This has significantly diminished my belief in the proposition that power makes people more selfish in the cookie scenario. I still believe it is somewhat more likely to be true because of my priors, but this study didn't contribute much.