Bad Genes?


January 2013
Ivan Obolensky


One of the questions about genetics is to what extent genes determine human behavior. If the answer is that genes are a major determinant of long-term human accomplishment, then should we look at our beliefs regarding free will and culpability in light of this? Should we also examine eradicating those genes that lead to extreme antisocial behavior?

Consider the following: what if one’s genetic make-up predisposes one to criminal conduct? What if simply having a certain collection of genes increases the likelihood one will commit a violent crime and end up in prison by a factor of 8 to 10 times the likelihood of those that don’t have that particular gene set?

Suppose this is true? If so, what should society do with this information?

Do we screen for this set of genes? Does government have the responsibility of isolating those with that genetic makeup? If all crime could be reduced by as much as 90%, would it be in society’s best interests to pursue some kind of preemptive handling?

The following statistics are from the U.S. Department of Justice:

  1. Of the 15,664 convicted of homicide, 14,196 had this particular set of genes.
  2. Of the 2,208,000 jailed for armed robbery 2,051,000 had this same gene set.
  3. Of the 452,000 who committed sexual assault, 442,000 or 97.8% also had this gene grouping.1

Before we examine the specifics of this particular collection of genes, one might conclude from the above that there are bad genes.

But can any gene be bad when one considers that its existence must have contributed in some way to the long-term survival of a species, or at the worst, not contributed to its extinction? Those that were counter, or non-survival, would have been eliminated over the course of many successive generations. Those that remained have proven their merit by the fact that the species is still around.

Yet one hears in the press of research groups searching for cancer and tumor-creating genes to effect a cure which would imply bad genes must exist, but this is likely to be too simplistic. Genes are after all context-driven.

For instance, environments can change, and a gene that was once extremely useful in the past can be looked at from the modern view as suspect.2

As an example, much of the body’s communication is carried out by small cell-signaling molecules. One such class of molecules is called Cytokines. They can be functionally divided into two groups.

The first is pro-inflammatory (Th1) and promotes inflammation to fight intruders and parasites. The second is anti-inflammatory (Th2) and regulates the degree of inflammation to prevent tissue damage that would result if the inflammation went on unchecked.

Take, for example, the gene, or combination of genes, that generates the Th2 response.

One of the theories about the rising instances of child allergies is that they are a byproduct of our overly clean and super-sanitized society.

Many allergists believe that these allergies are a result of a Th2 imbalance.

In humankind’s distant past as a hunter-gatherer, a large inflammatory Th1 response was needed to periodically remove excessive amounts of worms from the gut. These were ingested as a result of a foraging diet. A large Th2 reaction was needed to regulate and control the cleansing inflammation.

In today’s world, if one is constantly surrounded by a super-sanitized environment, the need for such large amounts of inflammation is less. The unmodified anti-inflammatory reaction to smaller amounts of inflammation may be excessive. The result is an unintended allergic reaction from the imbalance.3

The Th2 gene is not intrinsically bad. It does what it is supposed to do, and we would not survive well without it. Our perception of what it does from just the context of allergies might make it appear bad.

The Th1/Th2 response also illustrates an important method of control the body uses to regulate itself. The body utilizes many processes that are not simply on but are both on and off simultaneously, like someone driving with one foot on the gas and the other on the brake.

One might look at the body as a complex set of switches. If it were a kitchen, it would mean that if one turned on the stove, it might not operate because there exists another switch that is also on, keeping the stove turned off. This brings out another feature of genetics: just because the gene exists does not necessarily mean that it will be expressed.

On a practical side, another view of genetics is to translate genes as abilities. One might therefore ask: if there are no bad genes, can a bad ability exist? One often hears someone say that a person they know is too controlling, too stubborn, too messy, too dramatic, or too dishonest. One might consider these attributes as bad behavioral patterns and attempt to eradicate them.

Taking a page from genetics, the ability to do something and the ability to not do something are both abilities and considering any one of them bad or good is too simple. Time spent concentrating on getting rid of one’s bad attributes might be time better spent on enhancing those things one does well, which might be many more than one thinks. After all, if functionally there are no bad genes, how could there be bad abilities. It is the context that matters.

What about the gene set mentioned above which produces 90% of the world’s crime? If you guessed that this set of genes creates those that are male, you would be correct.

If one is born male, one is much more likely to commit a crime than if one is born female. Why is this? In truth we do not know, but the question still remains: Would it be worth some sort of governmental preemptive handling to reduce the male population? Law and order advocates might agree while more liberal elements might respond with “absolutely not”.

Of course, without knowing that the previous data referred to the half of humankind that is male, one might have considered a preemptive handling as a possible solution. Once one had the full information, one might disagree completely with such a choice, but with a vague sense of unease because the situation is pressing and perhaps something should be done.

Lest one think this is all imaginary, and a preemptive solution unlikely, it has already been implemented to some degree with little or no fanfare. The U.S. has by far the largest prison population in the world. It contains only 5 percent of the world’s population but has 25% of the entire world’s prisoners. This amounts to 2.3 million criminals behind bars. Almost all of them are male.4

North Korea may not be able to match the percentage of population incarcerated that the United States has managed, but has gone a step further by imprisoning the criminal and the subsequent two generations, to ensure the criminal’s genetic line does not interact with society for life or dies out altogether.

Of course, this article is simply pointing out certain facts. One might feel torn between two extremes of feeling something should be done about criminality that is equally matched by ethical considerations as to human freedoms.

Feeling one is being pulled in two opposite directions may not necessarily be a bad place to be nor may it be unique. Eradicating something completely may be far more destructive than just keeping it and attempting to control it with an opposing mechanism. In nature, as well as in governments and politics, such dichotomies of both yes and no, push and pull, and on and off operating simultaneously are now appearing to be more the norm than the exception.

Consider that there are 20,000 proper genes that account for only 3% of the human genome, with the genetic balance of 97% comprising an additional 4,000,000 regulatory elements whose functions now appear to be suppressing and activating them. Those additional elements were once considered simply junk DNA (a term coined in 1972 by Susumu Ohno for that part of the human genome that had no discernible function at the time).

In 2012, ENCODE, the Encyclopedia of DNA Elements, which succeeded the Human Genome project, reported that 80% of these supposedly useless bits had a regulatory function with more being discovered.5

Control of gene expression is vastly larger and more complicated than that of the gene itself. There are many parts that may turn a particular gene on and many more parts that turn it off, all working simultaneously.

Perhaps nature, as well as humankind, when confronting certain issues must straddle both sides. Perhaps, too, our concept of over-regulation is meager compared to what is happening genetically within us every day.


  1. Eagleman, D. (2011). Incognito, The Secret Lives of the Brain. New York, NY: Pantheon Books
  2. Ridley, M. (1999). Genome, The Autobiography of a Species in 23 Chapters. New York, NY: HarperCollins
  3. Berger, A. (2000). Th1 and Th2 responses: what are they? BMJ, v.321 (7258); Aug 12, 2000, PMC 27457. Retrieved January 10, 2013 from
  4. Liptak, A. (2008). U.S. prison population dwarfs that of other nations. The New York Times. Retrieved January 10, 2013 from
  5. Yong, E. (2012) ENCODE: the rough guide to the human genome. Discover. Retrieved January 10, 2013 from

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©2013 Ivan Obolensky. All rights reserved. No part of this publication can be reproduced without the written permission from the author.

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