Abnormalities in hair trace elements as indicators of aberrant behavior

Area of Science:

• Neuroscience
• Toxicology
• Forensic Science

Background:

• Impulsive and violent behavior are sometimes linked to brain dysfunction or damage.
• Previous research explored connections between toxic metals and aberrant behavior, with mixed results.

Purpose of the Study:

• To investigate the relationship between potentially toxic metals and violent behavior using hair analysis.
• To examine trace element levels, specifically manganese, in individuals incarcerated for violent offenses.

Main Methods:

• Hair samples were analyzed for trace elements using nonintrusive techniques.
• Three phases of study were conducted, controlling for potential artifacts like cooking utensils and prison environment.
• Violent and nonviolent incarcerated individuals were compared.

Main Results:

• High levels of lead, cadmium, and copper were not replicated from previous studies.
• Significantly elevated manganese levels were consistently found in the hair of violent versus nonviolent subjects across multiple study phases (P < .0001).

Conclusions:

• The study did not find a link between lead, cadmium, or copper and violent behavior in this cohort.
• Elevated hair manganese levels were significantly associated with violent behavior, independent of prison environment or hygiene products.
• The exact mechanism linking manganese to violent behavior remains unclear, with potential influences from alcohol, diet, or psychosocial factors suggested.