Wednesday, April 16, 2014

Personality - tendencies versus exhibited traits

Figuring out what makes someone tick is a fascinating past-time, especially figuring out yourself.  Some of the learning/personality tests/sorters I've investigated are: the corporate standby MBTI/Keirsey (INTJ), the academic favorite Five Factor (moderately-high Openness, moderately Conscientious, low Extraversion, low Agreeableness, high Neuroticism), the educator beloved Multiple Intelligences (Logical/Mathematical & Intrapersonal, followed closely by Verbal/Linguistic), the adult learning go-to Kolb Learning Style Inventory (Convergent), the not so known Ansir (Eccentrik thinker, Eccentrik worker, Visionary emoter), the clinical MMPI (results too complex for those not trained in interpreting it), and the mystic Enneagram (5 - Investigator).

My biggest problem with these tests is that some people see them as meaning your personality is carved in stone, despite the fact that research in human development shows that healthy personalities change over time and adapt to circumstances, even though the basic tendencies will still be evident at some level. An example given by David L. Guttman, in Reclaimed powers: Toward a new psychology of men and women in later life, is that men tend to become more nurturing as they age, while women become more assertive. Many researchers attribute this to cultural and health factors, which necessitate changes in their behaviors.

In simple terms, what I'm trying to say is that just because someone has a tendency towards being disagreeable, doesn't necessarily mean that they are always going to disagree or are unable to understand the importance of being agreeable.  It may mean that they have to consider the details more fully before they agree with something.  Or they may bite their tongues and agree for the sake of a more important goal.

As I stated in my last post, I found out that there have been some genes associated with certain personality traits, especially the Five Factor model. From Wikipedia's entry about this (retrieved 4/16/2014), the research shows that personality is only partially determined by genetics:
Twin studies suggest that heritability and environmental factors equally influence all five factors to the same degree. Among four recent twin studies, the mean percentage for heritability was calculated for each personality and it was concluded that heritability influenced the five factors broadly. The self-report measures were as follows: openness to experience was estimated to have a 57% genetic influence, extraversion 54%, conscientiousness 49%, neuroticism 48%, and agreeableness 42%.
(For you spelling purists, the academic/clinical/technical term is actually spelled "extraversion", not "extroversion". I know, it rubs against the grain.  But the original term was "extravert" and that is what is used in the Five Factors research.  "Extrovert" is an alternate version commonly used by the general populace. )

This first gene SNP is the one that made me search for personality results.  I was rather floored by the idea that my genes could influence my avoidance of errors and persistence, even though I've known for years that the genetic roots of personality were being researched. The bolding in the cited material has been added by me to highlight which aspects of the gene I am talking about.

Normal (A2/A2): Better avoidance of errors. Normal OCD risk, normal Tardive Diskinesia risk, lower ADHD risk. Less Alcohol dependence. Higher risk of Postoperative Nausea. Lower obesity. Bupropion is ... This DRD2 TaqIA A2/A2 version causes a normal amount of Dopamine Receptors. Learns from mistakes more easily. Men may have a higher risk of Obsessive Compulsive Disorder but lower risk of ADHD. Women have higher Persistence. Higher risk of Tardive Diskinesia when taking dopamine receptor antagonists. Lower risk of alcoholism and smoking addiction. Faster recovery from traumatic brain injury. 1.6x risk of early postoperative nausea within 6 hours of surgery. Bupropion (Wellbutrin, Budeprion, Prexaton, Elontril, Aplenzin, Zyban, Voxra) works to quit smoking. Lower obesity due to increased pleasure response to food.
I've started with this SNP, not only because it was the first personality gene I came across on my report, but as a matter of transparency in regards to my beliefs in the control we have over our own behavior.  It has occurred to me that part of the reason I so firmly believe that I can modify my own behavior is because I am genetically primed for the persistence it takes to do it.  That's not to say that I don't have other genetic and environmental factors that get in the way.  It's hard to persist in something when you're depressed and/or in pain - and there's a lot to be said for choosing your battles.  So, my apologies if I sound too gun-ho to those who must struggle harder with this things, along with my utmost respect for those who have managed behavioral changes despite the lack of this SNP to help them.

Probably the best example I can give of my persistence is something that happened back when I was a QA lab technician.  Because of my computer background and skills, I did a lot of the programming in my department.  One day a manager from another department told me that I programmed weirdly.  I turned from my monitor and asked him what he meant by that.  He said, "If you can't program straight through a problem, you don't let it stop you. You either program your way over it, around it, or tunnel underneath it."  I looked at him as if he had grown two more heads, because as far as I was concerned that's the way you're supposed to solve problems. And if all else fails, there's always C4. (I suspect both Adam Savage and Jamie Hyneman of Mythbusters have a similar gene.)

You have a SNP in the oxytocin receptor which may make you less empathetic than most people. When under stress you may have more difficulty recognizing the emotional state of others which impacts loneliness, parenting, and socializing skills.
Some studies have suggested that the A;G genotype is associated with an intermediate level of empathy (compared to the G;G and A;A genotypes), although most report that A;G and A;A individuals have similar levels of empathy and stress handling capabilities.
I highlighted the "may" because a few friends protested against the idea that I am anything but empathetic.  Even I was a little bit surprised by this, but then I realized that empathy is a skill I actively work for and it wears me out after a while, even though on the surface, I appear to be all sorts of touchy-feeling.

Going back to the main rs53576 article in SNPedia, we find this reference:
[PMID 19015103] This study examined the association between the OXTR gene and parenting. A total of 176 mothers of toddlers were included in the study. After controlling for marital discord, depression, and education status, rs53576 was found to significantly correlate with parenting, with the G;G genotype being associated with a significantly more sensitive parenting style than A;A or A;G genotypes. However, they concluded that the major factor influencing parenting was the maternal education level.
At the moment I work in a position where my ability to be empathetic is tracked and enforced, increasing my skill in that area.  I work at it because I recognize its importance in my daily life.  However, it is something I have to make an effort for when I am under stress or distracted.  But then Daniel Goleman states in his TED talk that the most important factor in determining whether or not someone will act like a good Samaritan (which requires empathy) is if whether or not they feel rushed. At work I manage this "rushed" aspect by making sure I ground myself between customers, using my acquired knowledge from my behavioral studies.

less-efficient serotonin processing; increased susceptibility to novelty seeking
I can see this.  I like keeping my mind busy.  However, I don’t usually seek novelty in social engagements as tested in the Big Five personality test.  Which is rather amusing when you realize how diverse and eclectic my friends are.  While this gene SNP is not directly linked to openness in Five Factor (or Big Five) Personality test (which I score between normal and high on) I would think that someone who was susceptible to novelty seeking, would also be open to new experiences.  When I got my report rs644148(T;T) was also listed as a possible indicator of openness, but the research on it is not conclusive at the moment due to lack of sampling.

That "normal" looks pretty uninformative until you compare it to rs1611115(T:T):
Personality disorder patients carrying the DBH TT genotype exhibited higher neuroticism and novelty seeking scores as compared to individuals with the (C;C) or (C;T) genotype. Analyses on the level of the neuroticism and novelty seeking subscales revealed that the DBH (T;T) genotype was primarily associated with personality features related to impulsiveness and aggressive hostility. Also adult ADHD patients carrying the homozygous (T;T) genotypes displayed by significantly increased neuroticism scores; when both personality disorder and adult ADHD patient were analyzed together, (T;T) carriers also displayed by significantly lower conscientiousness levels. [PMID 18982239]
I'm guessing this is why I score as average on conscientiousness on the Five Factor test. rs35753505(C;T) doesn't have a real entry to itself yet, but [PMID 18455369] says that "C allele carriers associated with higher (NEO-FFI) scores of neuroticism and lower scores of conscientiousness in a sample of 523 healthy individuals." Yet another case of me only having one allele for lower conscientiousness. It's a good thing that I have rs1800497(C;C) working for me - and I understand the need for conscientiousness.

My DNA test could only genotype one extraversion gene SNP - rs1800544(C;G)
[PMID 17894416] (Estonian Children Personality Behavior and Health Study subset, n = 419) GG genotype carriers had significantly higher scores on an assessment of depression, and significantly lower scores on morality and orderliness compared to CC carriers. girls with CC and CG genotypes scored higher than boys with the same genotypes on an assessment of extraversion. boys with GG genotypes, however, scored higher than girls with GG genotypes.
So, I am more extraverted than a male version of myself would be. I could see the benefit of that in a society where women were gatherers and males were hunters. Like I said, the genotype on the other SNP (rs1801252) didn't come through, so I have no idea if they match my low extraversion results. I'm guessing that I may have the (A;G) genotype though, since glycine carriers show "increased odds of low or very low extraversion levels in this particular study" - [PMID 15312808] Of course, my introversion may be from other factors.

normal - genotypes A/A were significantly associated with agreeableness scores. 
Okay, I’m not the A/A genotype. Nor am I the A/C genotype, which since my test results has also been link to higher agreeableness scores. So, it’s not surprising that I always test as Low Agreeableness on the Big Five Personality test.  I used to have an email tag that read: "I disagree with everyone, sooner or later - it's part of my charm."

The A allele of the CLOCK gene SNP rs6832769 was associated with lessened agreeableness (p = 0.00000871) in a group of 3972 Sardinians. The effect remained significant in the replicative American sample, but failed to achieve significance in the Norwegian sample and third sample (though the combined p value remained significant at 0.000865). 
And I am an American with two A alleles.  It's not that I'm not capable of being agreeable - just don't expect me to agree with you automatically.  If you're someone who believes that a friend/lover should agree with you without checking out the situation, no matter what, then I'm not going to be a close pal of yours. In fact, push it and it is possible I will become your Devil Incarnate.  Luckily for me, my best friend treasures this trait, and considers it one of my more valuable contributions to humanity.

There is another gene SNP (rs1984362) which may also affect agreeableness, but exactly how has yet to be determined.

The G allele of SNAP25 gene SNP rs362584 was associated with increased neurotic traits (combined p value = 0.0000522) in a group of 3972 Sardinians, and two smaller replicative samples from the USA and Netherlands (the replicative samples were not significant by themselves, with the Netherlands sample showing considerably less of a trend)

Rs35753505 (SNP8NRG221533) is located within the 5'-flanking region of the NRG1 (Neuregulin 1) gene. g2b2mh blog rs35753505(C;C) correlates with frontal brain having to working harder during a working memory task. personality traits - C allele carriers associated with higher (NEO-FFI) scores of neuroticism and lower scores of conscientiousness in a sample of 523 healthy individuals The results suggest that subjects with risk alleles show hyperactivations in areas associated with elaborate episodic memory encoding and retrieval strategies.

I already referenced the rs35753505(C;T) SNP in the discussion of conscientiousness.  Between these two genes, it's understandable that I usually score between normal and high on neuroticism. 

Now, some of you may have read the NY Times piece on the Worrier-Warrior gene.  And you may be wondering, what version does she have?  Well, let me share the two SNPs that showed up in my results:

rs4680 (Val158Met) is a well studied SNP in the COMT gene. 23andMe blog summarizes them as *rs4680(A) = Worrier. Met, more exploratory, lower COMT enzymatic activity, therefore higher dopamine levels; lower pain threshold, enhanced vulnerability to stress, yet also more efficient at processing information under most conditions *rs4680(G) = Warrior. Val, less exploratory, higher COMT enzymatic activity, therefore lower dopamine levels; higher pain threshold, better stress resiliency, albeit with a modest reduction in executive cognition performance under most conditions

Probably one Warrior Gene and one non-Warrior Gene. Women with this combination usually have the 3 repeat MAOA Warrior Gene on one X chromosome and the 4 or 5 repeat MAOA non-Warrior Gene on the other X chromosome. 
And the answer is - I'm half and half, or a worrier-warrior, which in retrospect fits me perfectly.  I actually have several other genetic risk factors for anxiety; however, not for social anxiety.  It will be interesting to see what further research can reveal. But no matter what, I will always remember that it's up to me to decide how to use my genetic tendencies.  While they may have a 50% voice in my behavior, they are not the final word on it.

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