Oct 15

Recent research (1) shows how physical contact can promote trust, even among complete strangers. Paul Zak, a neuroeconomist at Claremont Graduate University (together with Vera Morhenn, Jang Woo Park, and Elisabeth Piper), studies the links between levels of oxytocin (the “bonding” hormone) in relation to economic decision-making. In their study, they looked at participants’ responses in the Trust Game when they were (or were not) given massages. First, let’s take a look at how the classic Trust Game works between two players (who never meet):

  • Player 1 gets some money ($10 in this case) and the option to send none, some, or all of it to Player 2, knowing that the money that is sent will be tripled on its way into Player 2’s hands. So, if Player 1 decides to send $4 to Player 2 (and keep $6), Player 2 will receive $12 ($4 x 3).
  • Player 2 then has the option of sending none, some, or all of the money back.

Paul and his collaborators found that a mere 15-minute massage increased the amount of oxytocin in the bloodstream, leading participants to be more trusting of their anonymous partners in the game. Those who were massaged (women, especially) were primed to be more empathetic and trusting, ultimately sacrificing more to achieve mutual benefit. When massaged, Player 1 sent more money and when massaged Player 2 gave more money back.

But it’s probably not just oxytocin guiding these trusting gamers. Another study from Cedars-Sinai Medical Center (2) showed that those who received a 45-minute Swedish massage (as compared to a light-touch control group) had decreased levels of the hormones cortisol (released during stress) and vasopressin (linked to aggression and cortisol release). Basically, the Swedish massage relaxed participants, decreasing their physiological stress response.

In addition, An experiment conducted by Jonathan Levav and Jennifer Argo (3) showed that participants who were physically touched by a female experimenter (on the shoulder or with a handshake) made riskier financial decisions like gambling or investing money. Why? The contact made them feel secure and safe from harm. Consequently, like their massaged counterparts, they were more willing to take risks for potentially greater gains.

Being physically touched, whether with a kneading massage or a comforting pat on the shoulder, seems to encourages cooperative behavior. While these decisions may benefit others more than ourselves (at least in terms of immediate monetary gain), they are not necessarily ill-advised. In fact, the decision-makers who gave money to an anonymous partner ultimately felt better about their choices.

With this in mind, we purchased a massage chair in the Center for Advanced Hindsight. Now, we are looking for volunteers to help us test what other benefits we can get from massage.

1: Vera B. Morhenn, Jang Woo Park, Elisabeth Piper & Paul J. Zak. “Monetary sacrifice among strangers is mediated by endogenous oxytocin release after physical contact”, Evolution and Human Behavior, 29(375–383), 2008.

2: Mark H. Rapaport, Pamela Schettler & Catherine Bresee. “A Preliminary Study of the Effects of a Single Session of Swedish Massage on Hypothalamic–Pituitary–Adrenal and Immune Function in Normal Individuals”. The Journal Of Alternative And Complementary Medicine, 16 (1-10), 2010.

3: Psychological Science (2010), Jonathan Levav and Jennifer J. Argo, Physical Contact and Financial Risk Taking