Damage to dorsolateral prefrontal cortex affects tradeoffs between honesty and self-interest

This study uses data from patients with damage to specific parts of the frontal cortex to provide causal evidence for the role of the dorsolateral prefrontal cortex in enabling honest behavior. Damage to this area was associated with decisions that prioritized the decision-maker's own self-interest, at the cost of honesty. Substantial correlational evidence suggests that prefrontal regions are critical to honest and dishonest behavior, but causal evidence specifying the nature of this involvement remains absent. We found that lesions of the human dorsolateral prefrontal cortex (DLPFC) decreased the effect of honesty concerns on behavior in economic games that pit honesty motives against self-interest, but did not affect decisions when honesty concerns were absent. These results point to a causal role for DLPFC in honest behavior.