🧠

Neuroscience of Homicide and Brain Structure

Apr 26, 2025

Lecture Notes: Neuroscientific Study on Brains of Incarcerated Men

Introduction

  • Research Focus: Examining differences in brain structures, specifically gray matter, in murderers vs. other criminals.
  • Lead Researcher: Jean Decety, UChicago neuroscientist
  • Collaborator: Kent Kiehl, University of New Mexico
  • Published in: Brain Imaging and Behavior, July 5, 2019

Study Details

  • Sample Size: Over 800 incarcerated men
  • Regions Studied: Gray matter differences in orbitofrontal cortex, anterior temporal lobes
  • Groups:
    • 203 individuals: Homicide or attempted homicide
    • 475 individuals: Violent crimes (e.g., aggravated battery/assault, armed robbery)
    • 130 individuals: Non-violent or minimally violent crimes
  • Exclusions: Accomplices, accidental death, individuals with brain injuries or psychiatric disorders

Key Findings

  • Reduced Gray Matter in Murderers:
    • Less gray matter in regions responsible for emotion, behavior control, and social cognition
    • Implications for empathy and morality processing
  • Importance of Gray Matter:
    • More gray matter equates to more cells (neurons, glia); crucial for processing emotional data and controlling behavior

Research Significance

  • Innovative Approach: Largest sample size for this kind of study
  • Control for Confounding Factors: Psychosis and other psychiatric disorders
  • Future Research: Ongoing studies on high-risk youths to assess predictive value of identified brain regions for homicidal behavior

Additional Contributors

  • Ashly Sajous-Turner: First author, University of New Mexico
  • Michael Koenigs: University of Wisconsin

Funding

  • National Institute of Mental Health
  • Macarthur Foundation Law and Neuroscience Project

Conclusion

  • Caution: No causal relationship established between gray matter reduction and homicide
  • Potential for Future Implications: Results may inform understanding of brain structures related to criminal behavior

Reference