MAOA-L on CSI

From http://ghr.nlm.nih.gov/gene/MAOA

By Heidi Hiatt

This week’s CSI episode was riveting even with Justin Bieber guest starring as a less than convincing troubled teen/domestic terrorist. There are not many episodes that are worth rewinding the show immediately to watch segments again, but this one was.

Besides the explosive subplot in which Bieber’s hair actually wound up a bit messy, Targets of Obsession pitted Dr. Ray Langston (Laurence Fishburne) against serial killer Nate Haskell (Bill Irwin) in court. Haskell had previously tried to stab Langston to death through the bars of his cell with a piece of his glasses.

Haskell decides to act as his own attorney and calls an expert witness, Dr. Corey, to the stand. Corey claims that Haskell has a gene that makes him 400 percent more likely to be aggressive, giving him a medical excuse for trying to murder Langston.

This exchange follows, with Haskell playing to the crowd that includes his adoring groupies:

Haskell: So Dr. Corey, it is your expert opinion that I cannot be held responsible for my actions, for any of them.

Corey: That is correct.

Haskell: So it’s true what they say, that I am a monster. But– a monster made of biology beyond my control. So– convicting me of attempted murder would be like convicting a blind man of being unable to see. Who’s the real victim here? Who’s the real victim?!

Langston is summoned to the witness stand and questioned by one of the prosecutors. He calls Corey’s assertions neuromythology, not neuroscience, pointing out the many conflicting studies on the subject. He goes on to explain that biology alone does not cause crime:

Langston: Alcoholics are genetically predisposed to alcoholism which is a known disease. But we don’t give drunks a pass if they decide to get behind the wheel of a vehicle and kill people. The law is interested in whether or not a person understands the different between right and wrong. And the defendant knows the difference between right and wrong. He takes pleasure in committing sadistic crimes that he knows are against the law. The fact that he has tried to cover up those crimes is evidence of his consciousness of guilt.

Prosecutor: No further questions, your honor.

Haskell: I have nothing but questions. Dr. Langton, are you a psychiatrist?

Langston: No.

Haskell: A neurologist?

Langston: No.

Haskell: A geneticist?

Langston: No, my field is research pathology.

Haskell: Then you have no expertise in this area at all. Correct?

Langston: No.

Haskell: No. You mean yes. You just testified to a complete lack of credentials. So, on what would you base any expertise?

Langston: Personal experience. Like you I was abused by an alcoholic father as a child. Like you I have the MAOA gene. DNA isn’t destiny. We’re all responsible for our own actions. I share the same gene with you, Nate, but I’ve never murdered anyone. I take satisfaction in bringing justice to victims, not killing them and torturing them.

I almost stood up and cheered. Oh yeah! Go Dr. Ray! As science increases our understanding of the biological factors that play into antisocial behavior, we can’t dismiss the importance of other factors, especially free will.

The gene in question here is a variant of the MAOA gene, sometimes called the warrior gene. Specifically, the variant known as MAOA-L is most often implicated in aggressive and antisocial behavior, although MAOA-H has entered into the discussion. The L indicates low activity of MAOA, and the H high activity.

Some researchers say that people with the active gene are more likely to respond with aggression when provoked, become mired in credit card debt, and join gangs. Childhood abuse or stress are supposedly the biggest triggers of this genetic trait. About a third of the people in Western populations have it.

The National Center for Biotechnology Information says that the MAOA gene “…encodes monoamine oxidase A, an enzyme that degrades amine neurotransmitters, such as dopamine, norepinephrine, and serotonin. The protein localizes to the mitochondrial outer membrane. The gene is adjacent to a related gene on the opposite strand of chromosome X.”

In their March 2008 article MAOA and the neurogenetic architecture of human aggression (Trends in Neurosciences, Vol. 31, Issue 3), Joshua Buckholtz and Andreas Meyer-Lindenberg make a similar point to what the fictional Dr. Langston did: “Although aggressive behaviors and temperament are highly heritable, clinical and trait associations for the most promising candidate gene for aggression, MAOA, have been largely inconsistent.” They go on to propose a methodology intended to resolve some of the inconsistencies, but their point is valid; this is a developing concept.

Our understanding of the human brain is increasing in leaps and bounds. We already know that it is possible to have a brain scan that appears the same as a sociopath’s, but not be a sociopath. You might have heard of James Fallon, the neuroscientist who discovered that his brain appears that way. He had a PET scan done when he learned of a high incidence of antisocial behavior on his dad’s side.

Fallon’s story is part of a 2010 Talk of the Nation show on NPR. The audio and transcript are at http://www.npr.org/templates/story/story.php?storyId=128339306. NPR host Neil Conan and correspondent Barbara Bradley Hagerty discussed how researchers like Fallon believe that both nature and nurture factor into sociopathic behavior:

Conan: So you can have a genetic disposition, but that is not fate.

Hagerty: That’s right, exactly.

While nature and nurture may well factor into behavior that harms others, I do not believe that biological and environmental factors are the only explanation of it. You can have a terrible, hellish childhood and still grow up to be a loving, considerate, productive member of society.

Even though biology and environment may increase the temptation to lash out in some people, a majority of human beings have the ability to consciously choose whether to indulge their inner demons. As MLK Jr. said, “Every man must decide whether he will walk in the light of creative altruism or in the darkness of destructive selfishness.”

If biology is the sole or the most influential factor in a person’s moral choices, then wouldn’t someone with no control over their actions be constantly making violent choices? Wouldn’t they frequently harm themselves? Or wouldn’t they be lashing out at random rather than targeting specific victims, or a specific type of victims? They would be like a runaway car with no brakes, striking everything in its path, not just selected objects.

Instead, people without conscience tend to use and consume specific others because of what they get out of it. They may engage in a cost-benefit analysis when selecting their victims. They may choose victims with a similarity to others who they perceive have wronged them. Many crimes are solved because of patterns and predictability, because criminals develop certain tastes.

While CSI‘s discussion of the MAOA gene was basic and designed for television, Langston’s point was right on the money. Haskell is not a victim; despite similar childhoods and genetics, Langston fights for victims while Haskell rapes and kills. Biology is not an excuse for criminal behavior.

Does our legal system believe that though? Already, in the United States and other countries, we have seen sentencing soften when neuroscientific evidence is used. It may seem merciful to go easy on the minority of the population that have certain biological characteristics. By doing so, we may be rewarding bad choices, freeing dangerous people to offend again.

If someone truly does not have control over their actions due to a biological factor, then society should be protected from them. They should not roam freely. Thus the biological theory backfires on itself. If a crime-causing condition is permanent, the only surefire way to protect everyone else is to keep such “zombies” locked up.

As a side note, the actor who plays Nate Haskell is shockingly believable in that role. He oozes sadism, narcissism, and lack of conscience. Originally a highly regarded circus clown, Bill Irwin has also been Elmo’s buddy Mr. Noodle and was in the Don’t Worry, Be Happy video with Robin Williams and Bobby McFerrin. His range is remarkable, and he and Fishburne are an excellent match.

I hesitate to bring up the stereotype about clowns and serial killers, but as I was writing this, a certain Jack Handey quote popped into my head: “To me, clowns aren’t funny. In fact, they’re kinda scary. I’ve wondered where this started, and I think it goes back to the time I went to the circus and a clown killed my dad.”

Well Jack, maybe that clown had MAOA-L, an eerily quiet orbital frontal cortex, a crappy life, no soul, and no concept of good and evil, so he should be free to return to the big top. Never mind that many of the other clowns grew up in less than ideal circumstances, are violent crime survivors, have faced various injustices, and even have the same genetics, but volunteer at a crisis clinic in their off time.

I look forward to learning more about the biology of criminals and watching how our legal system and society responds to those findings. It is a fascinating field and I’m all for increasing our knowledge of human biology as it relates to crime. I just don’t agree with using it as an excuse for crime. We are more than skin-covered robots with a predetermined destiny.



The “why” of his disease is less important than “what” you are going to do about your situation. -Sandra Brown