Scholars stress the importance of both biology and environment as they influence antisocial and criminal behaviors. Intriguing findings include:
-The brain enzyme monoamine oxidase A (MAOA) breaks down and inactivates neurotransmitters. Studies suggest that people with low MAOA are more aggressive and react more strongly to stress than those with high MAOA. Low levels of MAOA are more commonly found in males. Males who were abused as children and had lower levels of MAOA were nine times more likely as others to bully, fight, lie, steal and disobey during adolescence.
-People with healthy amygdalas (responsible for initiating rage, fear, aggression, etc.) respond to the distress of others with increased amygdala activation; conversely, those with low-responding amygdalas show little emotional response to others' distress, and therefore have problems empathizing.
-The prefrontal cortex is responsible for problem-solving, emotion, and complex thought. Studies show that adults with damage to this brain region tend to exhibit impulsive, aggressive behavior. Individuals with antisocial personality disorder displayed reduced prefrontal area AND lower activity in the region.
-Neurologists believe that the frontal lobe doesn't begin to mature until age 17 and isn't fully developed until age 25.
-Brain scans of young and adult brains showed similar amygdala activity upon perceiving a face that showed fear; however, the profrontal cortex only became activated in the adult brain and showed minimal response in the adolescent brain when perceiving fear.
-Many neurologists agree that adolescents, due to underdeveloped brain functions, have problems with predicting the consequences of risky actions and thus take more risks. Society deems many of these youths as "delinquent."
There have been direct correlations between the above concepts and criminal behavior; namely, people with the above items are more prone to committing criminal acts. However, it has also been shown that people who grow up without stability at home, who grew up in depressed neighborhoods, and who were exposed to criminal activity when young are also more likely to commit crime (for more details, see Think Criminology, Chapter 5, John Randolph Fuller).
Do you think that biological reasons underlie the problem with individuals committing crime, or is it more of their environment? Maybe both? What should the criminal justice system do about juveniles? Should they be held responsible for their actions, or is this unethical, considering that juveniles have underdeveloped brain regions? Does this mean they're not responsible for their crimes?
It seems from the examples presented both biology and the environment influence the correlation between youths and crime.
ReplyDeleteThe non-matured frontal lobe and the inability to determine the consequences of "risky actions" because of the undeveloped brain functions mentioned suggested the crimes committed may be blamed on the lack of development. But the justice system would have a hard time proving criminal acts were done due to undeveloped brain functions in the amygdala, the forntal lobe, or the prefrontal cortex without scans and in-depth studies.
The suggestion that antisocial personality disorders result from reduced prefrontal area development and lower activity was interesting. My question is what if the antisocial personality such as a quiet or meek personality, resulted from not the biological underdevelopment of the prefrontal cortex responsible for problem-solving and emotion, but from the environment? Similar to the suggestion that committing crime may result from both environment and biology it seems likely that any deviation in personality types must result from the same mixture of brain function development and childhood environment.
I also think your question about the roles of nature and nurture in juvenile criminal behavior is interesting. However, if all judges were required to consider these particular factors, it would be very difficult to draw the line between legitimate and illegitimate biological/environmental excuses for juvenile behavior. Without wanting to sound too harsh, I almost think this kind of consideration would encourage the lawyers of juvenile criminals to use upbringing or underdevelopment of brain regions as a “cop out” for bad actions.
ReplyDeleteWhen you mentioned the role of the brain enzyme monoamine oxidase A (MAOA), I started thinking about the serotonin deficiency that some people are born with. Because the neurotransmitter serotonin acts as a calming mediator of the effects of environmental stress, Caspi et al. (2003) looked at the relationship between serotonin deficiency and stress-induced depression in a longitudinal study. As opposed to non-depressed individuals, those who became depressed were more likely to carry a small deletion on the promoter region of the gene responsible for generating serotonin. In essence, a genetically-derived serotonin deficiency gives rise to an agitated or depressed personality-type that deters certain individuals from letting things go.
I also looked at an older study by Linnoila et al. (1983) involving 36 criminals. These authors found that the lowest levels of the serotonin metabolite 5-hydroxyindoleacetic acid (5HIAA) belonged to the most violent and impulsive offenders. Although I couldn’t seem to find current research articles that suggest that these people would have a greater likelihood of impulsive criminal behavior, I suppose it makes sense after considering your example of MAOA. Even though serotonin deficiency and MAOA help us understand impulsive personalities, do any of you think that they would have weight in a courtroom?
Caspi, A., Sugden, K., Moffitt, T.E., Taylor, A., Craig, I.W. et al. (2003). Depression: Moderation by a polymorphism in the 5-HT Gene. Science, 301(1), 386-389.
Linnoila, M. et al. (1983).Low cerebrospinal fluid 5-hydroxyindoleacetic acid concentration differentiates impulsive from non-impulsive violentbehavior. Life Science, 33(26), 2206-2614.
I thought that this post was very interesting and raised some great questions. I think that the contribution of biological/physiological factors and environmental factors both play a huge part in juveniles exhibiting criminal behavior. I believe that what you experience is quite influential to who you become and your beliefs about what are right and wrong. That being said, what you brought up about the MAOA and underdeveloped frontal lobe along with what Shannon brought up about serotonin could contribute significantly to these behaviors as well.
ReplyDeleteI don't think that these factors should be used in court but I for sure think that lawyers would love to use these to win cases. I completely agree with Shannon when she said that it would be a kind of cop out for these kids to get away with doing things that they should not. I think that even though these factors do contribute to your behavior, you should still be punished because it is probably a combination of a variety of factors, not just physiological that made them decide to commit the crime. I also agree with Lena in that it would be extremely time consuming and expensive to collect evidence to prove that the underdeveloped brain was the cause and also just because they have an underdeveloped brain does not mean that that is the sole reason for their actions.