Paul, you say the difference in the amount of money people choose to return to the person who trusted them can be explained by the touching they received, and the ocytocin it released in them. Is it not just as well possible that the massage relieved the participants of stress and/or made then feel better because their muscles were more relaxed etc.?
If this is true, then the massage would not be comparable to a handshake or even a hug and the experiment doesn't say all that much about touching and handshakes, right?