Last night as I got increasingly drunk with my flatmates, we descended into a huge debate about nature vs nurture.
I was interested to hear the opinions of my friends who study other sciences (psychology and chemistry) and how their life experiences shape them as this is something I haven’t really considered before. Considering the fact that I’m a scientist, it is strange that I lean more towards the nurture argument as opposed to the genetic nature argument.
When considering personality, it makes more sense to me that nurture influences individuals more than their genetic makeup. For instance, serial killers often have troubled childhoods and exhibit the same strange characteristics (ie killing animals). Whilst I was researching this, I was very shocked to discover that there is in fact a ‘serial killer‘ gene: MAOA. After a study with ‘violent’ and ‘extremely violent‘ prisoners in Finland, it was determined that the low-activity MAOA genotype was associated with violent offending. The criminals involved in this study had committed non pre-meditated crimes, and therefore the MAOA gene could be associated with violence on impulse. Another associated gene- CDH13- codes for neuronal membrane adhesion. Disturbed neural connectivity and CDH13 have been implied to be asssociated with ADHD. A core symptom of ADHD is impulsivity, which relates back to the violence in impulse.
Behavioural genetics is based off the results of many family, twin and adoptive studies. Personality is not determined by any single gene, however they are determined by the actions of multiples genes working in unison. Robert Plonin, a psychologist from Kings College London, has determined that genetic heritability accounts for 50% of the psychological differences between us. That insinuates that 50% should be credited to environment but Solomon argues that most of this 50% can not be attributed to the type of environmental changes that can be planned or readily affected. He says most of the environmental influences that can be moderated are really an expression of genetics.
After researching this for this post, my opinion has changed greatly. I have recognised how much DNA influences our personality and is central to how we respond to things.
What is your opinion? Leave a comment and let me know !!