There are large individual differences in sustainable behavior, and it is not well understood why some behave sustainably towards future generations while others do not. Moreover, previous research on this topic is rare and has mainly relied on subjective self-report measures. In this study, we measured cortical thickness as a stable and objective anatomical brain characteristic to explain individual differences in intergenerational sustainable behavior. We combined these neural task-independent data with individuals’ behaviors in a behavioral economic paradigm measuring sustainable behavior towards a future generation. We found that cortical thickness in the left dorsomedial prefrontal cortex (DMPFC), which is associated with perspective-taking abilities, and the left DLPFC, which is associated with self-control capacities, explained individual differences in intergenerational sustainable behavior. Individuals behaving intergenerationally sustainably were marked by greater cortical thickness in the DMPFC and DLPFC compared to individuals behaving intergenerationally unsustainably. By using a neural trait approach, we were able to differentiate intergenerational sustainable and unsustainable individuals, which allows us to speculate about the cognitive mechanisms underlying these individual differences.
