infonet-economy

In humans, two completely different motives may nevertheless lead to exactly the same behavior. Because we can't directly observe motives, modern economists often completely disregard them. However, Hein et al., using fMRI, show that different human motives can yield observable responses in the brain (see the Perspective by Gluth and Fontanesi). In empathy-based and reciprocity-based altruistic behavior, the direction and the strength of functional connectivity between specific brain regions were different for each motive. Moreover, the connectivity patterns were independent of the behavioral implications of the motives.
Goal-directed human behaviors are driven by motives. Motives are, however, purely mental constructs that are not directly observable. Here, we show that the brain’s functional network architecture captures information that predicts different motives behind the same altruistic act with high accuracy. In contrast, mere activity in these regions contains no information about motives.

Empathy-based altruism is primarily characterized by a positive connectivity from the anterior cingulate cortex (ACC) to the anterior insula (AI), whereas reciprocity-based altruism additionally invokes strong positive connectivity from the AI to the ACC and even stronger positive connectivity from the AI to the ventral striatum. Moreover, predominantly selfish individuals show distinct functional architectures compared to altruists, and they only increase altruistic behavior in response to empathy inductions, but not reciprocity inductions.