Scientists are investigating the influence of genetics on violent behavior by studying the "warrior gene." This gene mutation has been linked to aggression and affected criminal trials. Studies have found people with the gene variant are more combative and some populations with a history of warfare have a higher rate of the gene. However, the role of nature versus nurture is debated, as experts disagree on whether the gene excuses responsibility or if individuals still have control over their actions regardless of genetic predisposition.

1. Nature or Nurture Linked To Crime
Lloyd T Petersen
Governors State University

2. Scientists are investigating the “warrior gene.” They feel that
this is the cause to violent behavior. Are we born to be
violent?

3. WARNING
I have 2 video clips in this presentation that
are interesting and I recommend you view
them. I must warn you that the first one is
nearly 20 minutes but the second one is
only a few minutes. I will list a few key
points of each video if you choose not to
view them…

4. http://www.youtube.com/watch?v=
NlFB-l2vMSk&feature=related
A single gene is associated with violent behavior.
Now a debate over genetic screening.
A gene mutation for violent behavior.
It has affected criminal trials.
Are humans shaped by the environment or is it biological?
Nature has a bigger influence.
How will this new knowledge be used in the future?
Will we cross the line like the Nazi’s?
Nature and nurture make us who we are.

5. Whether in sports,
business or any
other activity,
scientists found
that people with
the Warrior Gene
variant were more
combative than
those without this
variant.

6. Several studies have found a
connection between the low-
activity of MAOA and aggression in
observational and survey-based
studies (Science).

7. “Only about a third of people in
Western populations have the low-
activity form of MAOA. By comparison,
low-activity MAOA has been reported
to be much more frequent
(approaching two-thirds of people) in
some populations that had a history of
warfare” (Science).

8. The results found
“Low-activity MAOA subjects displayed
slightly higher levels of aggression
overall than high-activity MAOA
subjects”.
“There was strong evidence for a gene-
by-environment interaction, such that
MAOA is less associated with the
occurrence of aggression in the low-
provocation condition”.
(Science Daily)

9. Is it a valid defense?

10. http://www.youtube.com/watch?v=qZ
XObpzs0jQ&feature=watch-vrec
Dr. Nita Farahaury
Associate Professor of Law and Philosophy
Vanderbilt School of Law
“If a scientific explanation exists then you can not assign blame, responsibility or stigma”
Dr. Kristene Doyle
Director of Clinical Services and Child and Family Services
Albert Ellis Institute
“regardless of genetic predisposition there needs to be accountability to their actions”
“don’t have control over our genes but we do have control over our thoughts and behaviors”

11. The experts can’t decide between
themselves. Do we blame nature? Do
we blame the environment? Do we
blame both?
Some say blame the gene and not
punish the person and others say that
even with the gene they still have a
choice…..

12. References
• "Warrior Gene" Predicts Aggressive Behavior After Provocation. (2009, January 23). Retrieved
November 19, 2012, from Science Daily:
http://www.sciencedaily.com/releases/2009/01/090121093343.htm
• Criminal Behaviour: Is Genetic Predisposition to Violence A Valid Defense? (2011, October 12).
Retrieved November 13, 2012, from YouTube:
http://www.youtube.com/watch?v=qZXObpzs0jQ&feature=watch-vrec
• Genetics of Black Violence - MAOA-gene. (2011, October 22). Retrieved November 15, 2012, from
YouTube: http://www.youtube.com/watch?v=NlFB-l2vMSk&feature=related