Daniel R. Weinberger

About the author: Daniel R. Weinberger is the chief of the Clinical Brain Disorders Branch, Division of Intramural Research Programs, at the National Institute of Mental Health.

School shootings occur because the prefrontal cortex in a teenage brain is not fully developed. The prefrontal cortex is the part of the brain that enables people to act rationally and resist violent impulses. However, the cortex is not fully functional until at least two decades after birth. Consequently, the adolescents responsible for school shootings are unable to control their impulses and are unaware of the long-range consequences of their actions.

[March 2001's] shootings at Santana High School in California led quickly to now-familiar attempts to explain the seemingly unexplainable in terms of culture and circumstance...