Since serial killers aren't naturally bad, what went wrong?

Crime & Security / Date: 05-19-2025

When it comes to serial killers, that line gets thrown around more than you’d think. But here’s the shocker—most of these people weren’t monsters as kids. They went to school. Ate dinner with their families. Laughed at jokes. So, what twisted the wiring? What flipped the switch?

This article peels back the layers of criminal psychology—not with stale textbook jargon, but with raw insights, real stories, and disturbing truths. We’ll debunk the myth that serial killers are all the same, dig into one terrifying case that changed everything, and wrap up with what you really need to know (and do) to spot the signs before it’s too late.

Myth-Busting the Serial Killer Stereotype

Let’s clear the air right away—serial killers are not always geniuses, loners, or covered in tattoos. Hollywood painted that picture, not science.

In fact, research from the FBI Behavioral Science Unit shows that the majority of serial killers aren’t isolated weirdos. They hold jobs. Many have families. Some, like Dennis Rader, aka the BTK killer, even ran church groups.

And forget the IQ myth. While a few—like Ted Kaczynski (The Unabomber)—were brilliant, most hover around the national average. So smarts alone don't predict the monster.

Here’s where it gets chilling: A 2022 deep-dive by Dr. Helen Morrison (forensic psychiatrist, author of My Life Among the Serial Killers) found that over 70% of serial killers had head trauma during childhood. Think about that. A blow to the head, a fall, an accident—and suddenly, the brain’s ability to regulate empathy or impulse control starts warping.

But brain damage isn’t the whole story…

Edmund Kemper: A Case That Upended the Script

You want to see the human mask crack wide open? Let’s talk Edmund Kemper—a 6'9", soft-spoken man who seemed more like a college professor than a killer.

Kemper’s early life was a cocktail of trauma: abused by his mother, locked in a basement, and rejected repeatedly. But he was also strangely self-aware. After murdering 10 people—including his own mom—he turned himself in.

In multiple interviews, Kemper casually described his crimes like he was reciting a recipe. No rage. No tears. Just... facts.

And here’s the twist: Kemper once took an IQ test and scored 145. He worked for a while helping law enforcement analyze other serial killers.

What the hell does that say about the human brain?

It says intelligence doesn’t protect against psychopathy. It masks it. Like makeup over a bruise.

Behind the Eyes: What Neuroscience Shows Us

In brain scans of serial killers, something keeps showing up: reduced activity in the prefrontal cortex. That’s the brain’s decision-maker. The filter. The seat of morality.

At the same time, the amygdala, which controls emotion and fear, is often overactive or underdeveloped. That creates a toxic combo: the person doesn’t feel guilt and doesn’t fear consequences.

Let's put it in extremely basic terms:

Brain Area	What It Should Do	What Happens in a Serial Killer’s Brain
Prefrontal Cortex	Think logically. Stop you from doing bad stuff.	Sluggish. Can’t make “good vs bad” choices.
Amygdala	Feel fear, empathy, emotional response.	Flat. Or totally overloaded. No empathy.

See the problem?

But again—not all killers show these patterns. And plenty of folks with similar brain activity never hurt anyone. So, brains aren't the only factor. Let’s talk nurture.

Childhood Horror Stories—Not Just in Movies

Serial killers almost always carry childhood scars. Not scraped knees. Emotional and physical trauma.

A 2019 study in the Journal of Criminal Psychology found that 85% of profiled serial killers reported early abuse—be it neglect, beatings, or sexual violence.

And that changes something inside. Like emotional scar tissue.

One example? One of the few female serial killers is Aileen Wuornos. She was abandoned, abused, and forced into sex work as a teenager. Her killings later weren’t just about money or thrill—they were (according to her) about survival and revenge.

But if trauma is gasoline, then genetics and mental illness are the match.

What the Experts Get Wrong (Yep, Even the FBI)

There’s been this long-standing belief—especially pushed in 90s TV—that serial killers follow patterns. That if you study enough crime scenes, you’ll start to see a “signature.”

Reality check: Many serial killers change their methods. Some stab. Others shoot. Some don’t even have a pattern beyond their urge.

The BTK killer went quiet for years. The Zodiac killer taunted police with letters but left almost no usable evidence. Ted Bundy used charm and charisma more than brute force.

The uncomfortable truth? Profiling isn’t a perfect science. It can help, but it’s often misused. Several killers, including Richard Ramirez (The Night Stalker), were misidentified by law enforcement early on because they didn’t “fit the mold.”