Personality: Nature vs. Nurture

[Mark Serene]

I'm really interested to know more about the nature vs. nurture debate when it comes to personality and behavior. What do genes have to do with personality? Is there any evidence for a "chemical imbalance" theory when it comes to mental disorders like depression and pathological anxiety? Are the genetic and chemical imbalance theories just marketing schemes for psychiatric drugs

and cop-outs for abusive parents?

 

Can we change our personality? How?

[Wuzzums]

Book recommendation: http://en.wikipedia.org/wiki/Nature_via_Nurture:_Genes,_Experience,_%26_What_Makes_Us_Human

[Pepin]

Depends on what you mean by personality. To a large extent we can override genetic predisposition to certain behaviors through repetition, but some may need to put in far more time and effort. Certain traits are extremely difficult to attain for many, while they are effortless for others.

 

Like with most anything, there is a combination of environment and genetics that will maximize or minimize particular potentialities. The nature/nurture concept to a degree breaks down in terms of ability, though vestiges can be reassembled in extreme cases. Athletes and top tier intellects have massive genetic components to their ability, and though environment had an effect, it is the genetic inheritance which is more at work.

 

In terms of issues which do not pertain to ability, research seems to indicate that traits such as introversion and extroversion are not very correlated with environment. In my opinion, particular ways of thinking tend to be more inherent, and these different ways of thinking influence personality.

 

Not much of an answer, but the factors are rather complex, especially in gaining accurate measurements. I think it is a mix, with environment either maximizing or minimizing certain traits, and other traits being generated either through the internal or external environment. I don't think it is one or the other.

[Mark Serene]

Thank you for the book recommendation and reply. It does seem to be very complex. I like the metaphor of genes being a light switch that the environment turns on and off. That is very interesting what you said, Pepin, about different ways of thinking being inherited. I appreciate the brain fuel!

[Kaki]

(...) Is there any evidence for a "chemical imbalance" theory when it comes to mental disorders like depression and pathological anxiety? ...)

 

I did some little researching lately for a friend who was considering taking antidepressants. I found this link especially helpful:

Serotonin and Depression: A Disconnect between the Advertisements and the Scientific Literature

 

concerning "chemial imbalance":

 

While neuroscience is a rapidly advancing field, to propose that researchers can objectively identify a “chemical imbalance” at the molecular level is not compatible with the extant science. In fact, there is no scientifically established ideal “chemical balance” of serotonin, let alone an identifiable pathological imbalance. To equate the impressive recent achievements of neuroscience with support for the serotonin hypothesis is a mistake.

 

With direct proof of serotonin deficiency in any mental disorder lacking, the claimed efficacy of SSRIs is often cited as indirect support for the serotonin hypothesis. Yet, this ex juvantibus line of reasoning (i.e., reasoning “backwards” to make assumptions about disease causation based on the response of the disease to a treatment) is logically problematic—the fact that aspirin cures headaches does not prove that headaches are due to low levels of aspirin in the brain.

 

If you go through the article you will find lots of links to studies which you can check as well!

Hope that helped!

[Sal9000]

I strongly recommend watching Sapolsky's lecture on youtube. He makes a pretty good point that genes, RNA, enzymes and the enviroment interact. There is not a single gene that makes you smart or tall, but transcription factors that influence the way the DNA gets copied (think of DNA as a blueprint and of transcription factors as craftsmen). Another important lesson that is less known outside of biology is that hereditary traits don't give you absolute values but relative ones. This means that gene b makes you 10% taller than gene a, and gene c makes you 10% taller than gene b. How tall you really become (say 193 cm) is entirely dependent on the enviroment. Another factoid that I was not aware of is the small sample size of monozygotal twins that grew up at different parents (around 30 twins).

Enjoy.

[Pepin]

Obviously chemicals like seratonin and dopamine are involved in mental health issues, but more as effects than causes. I think chemical imbalance claims are misguided in that they are likely not the ultimate cause.

 

It is like preventing a ship from crashing by changing water currents, as opposed to getting the captain to turn the wheel. Certainly the currents can cause a crash, especially unpredictable and violent ones, but current control would only be useful to help get someone to a calmer body of water. More so, guiding people away from violents waters to begin with would be a far better strategy.

 

With that said, drugs in conjunction with therapy for extreme cases might be needed to prevent a crash, but current management is very costly and ineffeciently beyond that. There are studies which show SSRIs and therapy are the most effective, with just SSRIs being not very effective at all, so I am unable to disreguard their use altogether, but I think the focus needs to be on prevention.

 

If someone gets in an accident and four of their close friends die, drugs with therapy might be the best path to deal with that. But in general, I do not thinks drugs are useful.

[Mark Serene]

Wow thanks for the replies. Its insane how huge the antidepressant industry is and how most of the research points to it being based on false premises. I think I remember Stef talking about how certain laws were lobbied for by psychiatrists and passed that somehow made it so that insurance companies were forced to cover these drugs. Does anyone have a link or know about the podcast I am talking about?

Also, I found this documentary to be pretty interesting. I'm not a huge fan of the narrator from Ripley's Believe it or Not, though haha. 

[Matt D]

Hi Mark,

 

I called into the show recently to ask about personality types. (First caller on December 19.)

If you haven't watched Stef's video on Nature v Nurture, that's a good place to start.

 

 

I also recommend this resource on behavior genetics and affect.

http://www.personality-project.org/revelle/publications/AR.html

 

 

 

 

[Mark Serene]

Thanks for the link to that presentation! It did a lot to clear things up in my minds around this issue. Epigenetics, folks. The personality is provoked.