Causal Evidence for the Neural Underpinnings of Subjective Happiness

Abstract Happiness is a central but poorly localized dimension of human experience, and causal evidence linking discrete brain regions to subjective happiness is scarce. We tested whether focal brain damage modulates self-reported happiness by measuring Subjective Happiness Scale (SHS) scores in 131 male veterans with penetrating traumatic brain injury (pTBI) and 33 matched healthy controls (HC), and by applying voxel-based lesion–symptom mapping within anatomically pre-defined brain regions. Overall, individuals with pTBI reported higher SHS scores than HC. VLSM identified two lesion clusters associated with increased happiness after injury: a small cluster in the right anterior cingulate cortex and a larger cluster in the right orbitofrontal cortex. These results provide causal evidence that right frontal circuitry—notably the ACC and OFC—modulates subjective happiness, challenging current accounts of motivational and emotional processing and pointing to targeted neural substrates for understanding and potentially modulating human happiness. Competing Interest Statement The authors have declared no competing interest. Footnotes ↵^ Note: Questions concerning the Vietnam Head Injury Study can be directed to Dr. Jordan Grafman. E-mail: jgrafman{at}northwestern.edu