Psychology Blog » Aggression http://www.oxfordschoolblogs.co.uk/psychcompanion/blog Psychology: The Online Companion Mon, 06 Feb 2012 10:37:56 +0000 en hourly 1 http://wordpress.org/?v=3.2.1 Risky behaviour http://www.oxfordschoolblogs.co.uk/psychcompanion/blog/risky-behaviour-1399/ http://www.oxfordschoolblogs.co.uk/psychcompanion/blog/risky-behaviour-1399/#comments Sun, 12 Jun 2011 10:34:06 +0000 Cara Flanagan http://www.oxfordschoolblogs.co.uk/psychcompanion/blog/?p=1399 One of the explanations for addiction is that some individuals have a biological predisposition because they inherit a particular form of dopamine receptor gene (if you want an explanation of dopamine receptor genes see second paragraph). An interesting link has been made between these genes and evolution. The argument goes that the dispersal of our distant ancestors from Africa was related to riskiness. Individuals with a predisposition to be impulsive and risky rather than careful and reflective would be more likely to explore and find new, desirable environments and would also cope better with new, challenging situations. Recent research has indeed found a link between specific dopamine genes and migration patterns i.e. migrants were more likely to have the version of the dopamine receptor gene that codes for risky behaviour. This shows that the gene has had an adaptive function, and may continue to do so.

Understanding dopamine receptor genes: There are different types of dopamine receptor such as D1R, D2R etc. (D for dopamine, R for receptor and the number denotes the type). The receptor is called D1R and the gene for that receptor is called DRD1, or D2R and DRD2 (which seems confusing to me, but there it is). For any gene there are different forms or allelles. So, for example, we all have a gene for D2R but the form of that gene differs. One person may have the G allele (which is associated with aggression) or the 1A allele (associated with addiction). In the study cited above (Matthews and Butler, 2011) the DRD4 gene was studied and the 7R and 2R versions were associated with risky behaviour whereas the 4R version was linked to being even tempered.

]]> http://www.oxfordschoolblogs.co.uk/psychcompanion/blog/risky-behaviour-1399/feed/ 0 Genes, free will, responsibility, murder? http://www.oxfordschoolblogs.co.uk/psychcompanion/blog/genes-free-will-responsibility-murder-223/ http://www.oxfordschoolblogs.co.uk/psychcompanion/blog/genes-free-will-responsibility-murder-223/#comments Tue, 17 Nov 2009 09:59:20 +0000 Evie Bentley http://www.oxfordschoolblogs.co.uk/psychcompanion/blog/?p=223 If you  smash your fist into someone’s body are you being aggressive and anti-social, or are you just doing what your genes programme you to do? The idea of genes affecting behaviour isn’t new and isn’t disputed, but the use of certain genes as a mitigating factor in criminal behaviour is a contentious issue. Genes have been used as part of the defence in cases of murder, and moral and ethical arguments around this use have focused on the low validity of the research evidence plus the generally accepted concepts of free will and personal responsibility. The argument has been taken a stage further now as a convicted murderer in Italy has had his sentence reduced partly because of his history of psychiatric illness and also partly because his genome includes five genes known to be associated with violent behaviour. One of these genes is a variant of MAOA, which codes for an enzyme which breaks down amines in the brain, and this low-activity variant correlates in research findings with violence and aggression, giving it its nickname the “warrior” gene. However, as we all know, correlations are not necessarily causal; and then there is the responsibility debate. So, what would you decide if you were on the jury, the defendant was clearly guilty of murder, but also had a gene profile predisposing him or her to violence and aggression?

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