Eating to trust

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 that we published in Psychological Science.

Interpersonal trust was assessed by the trust game, a task widely used in behavioral economics. This task measures the extent to which a participant (the trustor) trusts the trustee as reflected 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.

Colzato, L.S., Steenbergen, L., de Kwaadsteniet, E.W., Sellaro, R., Liepelt, R., & Hommel, B. (2013). Tryptophan promotes interpersonal trust. Psychological Science. DOI: 10.1177/0956797613500795

1 Comment

Marije Rot

Tryptophan is the amino acid precursor of the neurotransmitter serotonin, and the study is interesting because it supports other research on the role of serotonin in human social interaction. Keep in mind, however, that dietary tryptophan supplementation (which results in a significant increase in the intake of tryptophan relative to that of other amino acids) is not the same as simply eating more tryptophan-containing food (which contains the other amino acids as well). So while this blog post suggests otherwise, I believe that eating fish, soy, eggs, and spinach will not lead to increased interpersonal trust.