Nature vs. Nurture: What Drives People to Kill?

nature vs. nurture

Son of Sam letter

The debate of a nature vs. nurture is a controversial, longstanding debate with supporters on both sides. Some experts believe if you grow up in a loving home, you’re destined to become a good person. But that isn’t always the case. Ted Bundy springs to mind. He had a loving home, as did Jeffrey Dahmer. So, what went wrong?

What if a child grows up with loving parents, but where they’re located turns them into a monster for the mere fact that they must fight to stay alive? Then it wouldn’t matter how loving the parents are. If gunfire is a constant background noise, the child may learn from the streets. Genetics also play a role. Take an addict or alcoholic. Many experts believe it’s an inherited condition. So is a child of an alcoholic destined to become one? I’m not convinced. It’s difficult to see the issue as that black and white.

Several things are genetically inherited, ranging from gender, eye color, risks for certain diseases, exceptional talents, height, weight, etc. The concept of nature thus refers to biologically inherited tendencies and abilities of which may get revealed later as they age. In contrast, nurture can be defined as the different environmental factors which subject a person from birth to death.

Environmental factors involve numerous dimensions, including both physical environments and social environments (such as the neighborhood, media, and peer pressure.) Also, environmental factors have different levels of impact on human development, as well as multiple layers, ranging from immediate (families, friends, and neighborhoods) to bigger societal contexts (school systems and local governments) and even politics or global warming. These layers also impact other factors. For example, teenagers are exposed to peer pressure but also to parental ideals, community standards, and/or ethnic views.

Nature vs. nurture certainly isn’t black and white, and it’s these gray areas that intrigue me most.

What about crime?

There have been children from wealthy parents who raised complete monsters. Jeffrey Dahmer, for example. I bet his father never imagined young Jeffrey would someday slaughter, dissect, and cannibalize so many young men. It’s horrifying to consider what his father went through when he discovered the heinous actions of his son. In Dahmer’s case, I’d classify him as a psychopath. No matter how loving the home environment some kids just go rogue.

What about environment?nature vs. nurture

Does a young boy living in a crime-ridden section of the city need to learn how to fight in order to survive? What if that same child witnessed his own family members’ murders? An event like that would certainly increase his flight-or-fight response. As sad as it is to consider, some children have no choice but to meet violence with violence, or they could wind up dead. At the same time, one might ask why not rise above it? Again, is the issue really that black or white? We can never know what it feels like in someone else’s skin, so how can we sit in judgement?

Please don’t think I’m condoning murder or any other form of violence. I’m not. All I’m saying is, sometimes circumstances define our path in life. For example, if someone broke into my home with the intention to cause harm to my family, I wouldn’t hesitate to take their life. And I’d be well within my rights to do so, according to the Make My Day law — legally referred to as the Stand Your Ground law. Not all states have enacted this law, by the way, so if you’re using it in your writing check your jurisdiction first.

If I killed an intruder, would I then be considered a murderer? Technically, yes, but we know the circumstances surrounding my choice to kill. Does that then make murder okay? Nature vs. Nurture is a fascinating debate, because there really is no correct answer. Both sides make compelling arguments. It’s from this point of view—I’d kill to defend my love ones—that I look at the actions of others. A theory could be made that inner city kids who kill do so as a way of life, because they don’t know any other way. Doesn’t make it legal or acceptable, but it does make it easier to understand somehow.

In a NY University publication Beyond the Pleasure Principle, Donald C. Freud came up with two theories: death instinct and life instinct. The death instinct follows destructive behavior toward the society around them. What Freud found that led him to this theory was that out of those he had studied who’d experienced unpleasing experiences kept repeating those experiences, even though they were still unpleasing.

Opposite that is the life instinct. Freud believes people try to maintain a better life and try to achieve bigger goals for themselves. Born with these aggressive and destructive stimuli many serial killers go on to commit horrific crimes, even though they know what they’re doing is wrong.

It’s widely known that abuse does contribute to shaping a serial killer. To research this post, I read a fascinating study conducted by Heather Mitchell and Michael G. Aamodt at Radford University, using a list of 50 serial killers who fell into the lust killer category.

The study broke abuse into four categories.

Physical abuse — causing or allowing non-accidental physical injury to occur

Sexual abuse — sexual activity that met the criminal definition

Psychological abuse — inflicting emotional conflict or psychologically damaging the subject

Neglect — failing or refusing to provide adequate food, clothing, shelter, healthcare, or emotional nurturing

The results suggest childhood abuse among serial killers is higher than the general population across all types of abuse. Of the 50 serial killers included in the study, key findings were:

36% suffered physical abuse

26% sexual abuse

50% psychological abuse

18% neglect

2% having no reported abuse at all

The authors included data from 50 serial killers, broken into organized, disorganized, and mixed offenders, and found no difference in the frequency of abuse across these sub-types. If you’re interested, you can read the full study HERE.

Let’s look at a few examples that demonstrate nature vs. nurture.

Spree Killer Joanna Dennehey

Joanna Dennehey came from a loving home. Yet, she killed without remorse. In fact, she enjoyed every second of her murderous rampage.

As she raised the knife and plunged the blade into her final victim, she showed almost no emotion. “Oh, look, you’re bleeding,” she told John Rogers, who nearly died from his injuries. “I’d better do some more.”

In all, Dennehey murdered three men and seriously wounded two others over a 14 day killing spree. After stabbing her third victim, she phoned a friend and sang the Britney Spears song, “Oops… I Did It Again.”

This mother-of-two clearly sought notoriety as a serial killer, evident by her dancing around the room after watching a news report about the murders that started on March 19, 2016.  Why she pleaded guilty remains unclear, but I’m sure once the press dies down, she’ll offer an explanation to regain the spotlight.

I think it’s fair to file her under psychopath = nature.

Serial Killer Ed Gein

nature vs. nurtureBy all accounts, Ed Gein was a shy loner with an almost unnatural attachment to his mother. He remained in his family home all his life, and was devastated by his mother’s death in 1945. Ed had one brother, who some say may have been Ed’s first victim. While Ed exclusively killed women, it’s believed he killed his brother because of his lack of emotional attachment to their mother.

Ed’s parents remained married until his father’s death in 1940, but they had a notoriously unhappy marriage. As a result, his mother projected her anger and resentment on to her two sons, routinely abusing them and refusing to allow them to make friends with neighborhood kids. Ed’s mother also had some warped religious views, often using Bible passages to justify her cruel treatment of her sons. In her eyes, both boys were evil and unworthy, a belief they grew to accept.

The abusive upbringing is likely what shaped Ed’s future deviant behaviors. After his mother’s death, he strung up women in his barn, gutted them like deer, and used their skin, hair, and bones to craft furniture. Like Dahmer, he also cannibalized his victims. In 1957, Ed was arrested after the death of tavern owner Mary Hogan. He spent the remainder of his life at the Mendota Mental Health Institute in Madison, Wisconsin.

Because of his upbringing, I’ll say environmental factors caused his murderous rampage = nurture.

Serial Killer Robert Yates

A decorated military helicopter pilot and a National Guardsman, Robert Yates came from a loving, supportive home. From the time he could walk, his parents instilled Christian teachings in young Robert. By all accounts, he was an obedient child, dedicated student, and a team player on the Oak Harbor High School football team. No one could have predicted he’d turn into a monster.

The first body was discovered Feb. 22, 1990 and the killing continued for a decade. He liked to cruise the red-light district in a white Corvette, where Yates murdered 8 of at least 13 victims. Authorities believe the number is closer to 18. At trial, he admitted to two more slayings in Walla Walla in 1975 and the murder of a woman whose body was found in 1988.

“Bobby is a loving, caring and sensitive son, a fun-loving and giving brother, an understanding, generous and dedicated father, who enjoys playing ball, fishing and camping with his kids,” the three-paragraph statement said. “We feel deeply for the families who have experienced loss,” the statement said. “We ask that all judgments be reserved until the timely due process of law has been completed.” 
Signed, the Robert L. Yates family members.”

During the 5 ½ week trial, prosecutors told jurors this was Yates “evil hobby.” He killed for the thrill of it, because he enjoyed necrophilia. The judge sentenced him to 408 years in prison.

It’s safe to say Yates is a psychopath: nature.

Serial Killer David Berkowitz aka “Son of Sam”

David Berkowitz terrorized New York City between 1976 and 1977. Though his reign of terror was short lived, his name lives on. Berkowitz claimed that his crimes were instigated at the behest of the neighbor’s dog, which had been possessed by demons who told him to kill. His crimes differed from those of Dahmer, Gein and Bundy in that they didn’t include any psychosexual elements. Instead, Berkowitz shot his victims with a .44 caliber pistol. Originally he confessed to all 6, including wounding 4 others, but recanted 3 of the murders, insisting the other 3 murders were committed by members of his satanic cult.

As an infant, David was placed for adoption with a loving family, however, his adoptive mother died of breast cancer when he was a teen. His father remarried, but David didn’t like his new stepmother. He also stated his stepsister practiced witchcraft, a hobby which David also took an active interest.

In 1977, he was convicted of 6 murders and wounding 4 others and sentenced to 365 years in prison.

At first glance, it appears David suffered from psychological issues (the demon dog speaking to him), but perhaps his activities in witchcraft also played a role = nature or nurture? Maybe both.

Perhaps the most interesting of all is Serial Killer Joseph D. Miller

For more than two decades, people have been trying to get inside the mind of Joseph D. “Joey” Miller. Is he a mentally challenged man incapable of fully understanding his horrible crimes? Or is he a cold, calculating serial killer driven by a compulsion to rape and murder?

While raping and murdering up to five women and brutally assaulting two others, Joey maintained a domestic home life, with a wife and three children. A cunning killer, Joey packed a murder kit complete with beer to fool his victims into thinking the trip to the landfill was so they could party and have sex. He was also careful to choose only high-risk victims. After the kill, he disposed of their bodies in the landfill and covered them with debris. He would later return to “spend time” with them.

Some of the bodies went undiscovered for decades. And in two instances, a different man was convicted of the murders.

Joey later confessed…

The video confession runs about 30 min., but it’s a fascinating case study for crime writers.

From watching this confession I don’t buy that he’s mentally challenged or didn’t know right from wrong. Yet, he’s a tough candidate to classify within the nature vs. nurture guidelines. Because he mainly killed prostitutes who demanded more money or double-crossed him in some way, and because he states being haunted by their spirits as well as suffering nightmares, I’m inclined to say his environment played a key role = nurture.

What do you think of the nature vs. nurture debate?

About Sue Coletta

Member of Mystery Writers of America, Sisters in Crime, and International Thriller Writers, Sue Coletta is the bestselling, award-winning author of psychological thrillers and mysteries. OOTG Flash Fiction Offensive magazine published her flash fiction and her short stories are published in numerous anthologies and collections. InSinC Quarterly featured her forensic articles about Radiocarbon Dating and Skeletal Differences. In 2017, Feedspot awarded her Murder Blog as one of the Top 50 Crime Blogs on the net. Sue's also the communications manager for Forensic Science and the Serial Killer Project. As a way to help fellow crime writers, Sue created a team of crime experts (detectives, coroners, police captains, etc.) and founded #ACrimeChat on Twitter. She's also a proud member of the Kill Zone, where she blogs every other Monday.


  1. I think some people are just born “evil.”

    • You’re right, Traci. If we gave birth to a psychopath, there’s not much we could do about it, because often times the deviant behavior doesn’t show till later in life. On Discovery ID they based a show on the subject, entitled “Evil Lives Here.” Tagline: What if the person closest to you…were a devil in disguise?

  2. Thanks for this post–good timing. I am researching honor killers, who kill their sisters or daughters, people they love, with no remorse. They kill in the name of religion. I need a psychological scene at the end of my novel. One where the killer explains to the bereaved husband why he had to kill his sister “for her own good,” even though he loved her. I need to show his satisfaction and sadness in the same scene. I also need the irate husband to understand in a way. I will STUDY this post and your resources for assistance. If you have any other sources about killing in the name of religion, I’d love to know.

  3. There has to be ‘a nature’ seed in all those killers, or else all people suffering from difficult childhoods and/or abuse would become psychopaths. I guess ‘a nurture’ is a trigger for ‘a nature’ causes, in many cases.
    Anyway, another great article, Sue 😀 Congrats

    • Thanks, Mica! Not necessarily, no. Although, I do like your way of thinking. It makes it easier to swallow. But sometimes, a normal kid is pushed to the edge by circumstances alone (nurture). I’m thinking of kids who grow up in gang-ridden territories, for example. If we plucked that same child and put him in a safe neighborhood, he may go on to do great things with his life. It’s frightening to consider.

  4. I thoroughly enjoyed this post. Once again, another fascinating read. Thank you for the insight Sue.
    Joycelin Leahy recently posted…Feather Challenge – WatercolourMy Profile

  5. Very gruesome stuff. Just thinking about these killers and what they did is gut wrenching. I guess I don’t have it in me to dissect further than that! *shudder*

  6. Really interesting stuff today. I need to come back and watch the video later.

  7. Love the Miller confession video.
    Individual minds are wired differently. Neural pathways are constantly changing because of electrochemical stimuli. Both internal and external stimuli affect the brain, and psychopathic killers don’t think the way you or I do. Period.
    pauldaleanderson recently posted…Why so many serial killers?My Profile

  8. Nice job on this Sue. I hadn’t heard of the life vs. death instinct either, but it sounds plausible. I think Bundy still ranks among the scariest because he was so “normal.”

  9. Great post, Sue. I hadn’t heard of the death vs life instinct analysis but it makes sense. In my experience, most criminals (killers included) are mostly products of their environment and have a lot of contributing factors that developed over time. Some, however, are born bad to the core and I’m not sure if even the best psychiatrists can explain them. They sure make for fascinating characters, though!
    Garry Rodgers recently posted…HOW TO SCAM NIGERIAN FUNDS FOR YOUR TIME MACHINEMy Profile

    • They certainly do, Garry! But I wouldn’t want to meet one in an alley…at midnight…alone. I can see the headline: Crime Writer Killed by Serial Killer — Found Dead with Video Recorder

  10. This is an absolutely fascinating post! And the question definitely isn’t an easy one. The more we learn about psychology, adult choices and so on, the more we see that we can’t really say nature or nurture is responsible for the adults we turn out to be. We are a mix of our genes, our experiences, and our environment. And sometimes, our brain chemistry gets involved, too.

    • Exactly, Margot. I don’t know if you read Psychology Today, but watching the experts debate nature vs. nurture is absolutely fascinating. It seems the more we learn, the less certain we are about why people kill. There have been studies with identical twins, where one turned evil, one remained good. Both had an identical upbringing, with the same parents, in the same environment. The study muddied the waters even more.

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