The consistent pattern of men committing mass violence is rooted in biological evolution. Men are wired for aggression and physical confrontation, a trait historically selected for by women seeking protectors. This is a biological reality, not a surprising social anomaly.

Sociological research shows the era a person is born into—the "birth lottery of history"—is a more significant predictor of criminality than individual factors like psychology or poverty. Just a few years' difference can double the arrest rate for people from otherwise identical backgrounds.

To cope with the reality of raising a serial killer, Keyes's mother, a religious zealot, rationalized his actions as a divine message. She believed he was "put on this earth to warn humanity about the dangers of turning your back on God," a narcissistic survival instinct to absolve herself of responsibility.

In cases of extreme violence, we seldom investigate underlying biological factors unless there's an obvious "smoking gun" like a brain tumor. The discovery of a rare MAOA gene mutation causing extreme aggression in a Dutch family raises the question of how often people are labeled as "evil" without any search for an organic cause.

Israel Keyes, who had no birth certificate, social security number, or educational records, was not only accepted into the US Army but trained for special operations. This reveals a potential blind spot in military recruitment protocols and highlights how Keyes's inherent capabilities were valued and honed by a government institution.

Counterintuitively, the heritability of traits like cognition and personality increases from childhood into adulthood. This occurs because individuals increasingly select and shape their own environments based on their genetic predispositions, a process that amplifies the influence of their genes over time.

The onset of antisocial behavior before age 10 is one of the biggest predictors of a lifelong pattern of offending. Cold, callous aggression towards others or animals at this young age, often with a heavy genetic component, has a poor prognosis and currently has vanishingly few effective treatments.

The idea of a stable "criminal character" is a trap. Societal conditions can completely override individual traits like self-control. A person with high self-control in a high-crime era was just as likely to be arrested as a person with low self-control in a later, lower-crime era.

Unlike typical serial killers who have a preferred victim and operate in a specific area, Israel Keyes was dangerously unpredictable. He would fly to a random city, drive hundreds of miles to a pre-buried "kill kit," and abduct anyone, making his crimes nearly impossible to link or profile.