Eating to trust
The administration of the amino acid tryptophan (TRP) contained in food such as fish, soy, eggs and spinach promotes interpersonal trust. This is the outcome of a study by cognitive psychologist Lorenza Colzato and her fellow researchers at Leiden University and University of Muenster, published in Psychological Science.
Interpersonal trust was assessed by the trust game, a task widely used in behavioural economics. This task measures the extent to which a participant (the trustor) trusts the trustee in money units transferred from trustor to trustee. Participants transferred significantly more money to the trustee after the intake of TRP than after the intake of a neutral placebo.
The results support the idea that “we are what we eat”: the food one eats has a bearing on one’s state of mind. Food may thus act as a cognitive enhancer that modulates the way one thinks and perceives the physical and social world. In particular, the supplementation of TRP, or TRP-containing diets, may promote interpersonal trust in inexpensive, efficient, and healthy ways.