I know that the brain isn't some ethereal heavenly thing that just occurs.
It's made out of flesh and blood, sort of a biological computer.
If you combine your parents inherent traits, you get a result.
Yeah, that's what I was thinking.
I know that the brain isn't some ethereal heavenly thing that just occurs.
It's made out of flesh and blood, sort of a biological computer.
If you combine your parents inherent traits, you get a result.
I'm an INTJ from a family people who are almost all NT's of some kind. Another user told me that he's basically in the same boat. Is this typical? Is personality determined by DNA? You know, 'cause if it is, I'm going to rub it in the face of everyone that believes in Tabula Rasa (kidding! Seriously though, what's the deal?).
Typology is a pseudoscience, and there is absolutely no way to ascribe a science such as genetics to it.
You can't just look outwardly look at a trait as complex as personality and determine its level of inheritance. You would need to figure out actual genes that correlate with actual components of one's personality (these components could be labeled according to Jungian functions, I suppose), but we certainly have not gotten that far with genetics or neuroscience.
On another note, our phenotypes are a result of our environment (in this case, upbringing) and our genes. If your parents are both NTs and you are also an NT, it could be due to genes or it could be due to being raised in an NT environment. Ya know, the whole nature vs. nurture game.
It's quite silly to think, however, that both your parents being NTs and you are also being an NT is any indication that it's passed down through genes. This completely ignores environmental factors that go into creating our phenotypes.
I certainly don't know the science behind it, but do babies not display different temperaments and/or personalities? Some are more prone to crying and being easily scared, while others smile and laugh more often. We all begin trying to formulate the world around us at an early age, and it seems like even then, we might have the ability to be more emotional reactive or more logical reactive, no?
I'm just trying to think through all this.
wikipedia said:The relative importance of nature versus environment in determining the level of extraversion is controversial and the focus of many studies. Twin studies find a genetic component of 39% to 58%. In terms of the environmental component, the shared family environment appears to be far less important than individual environmental factors that are not shared between siblings.[13]
Eysenck proposed that extraversion was caused by variability in cortical arousal. He hypothesized that introverts are characterized by higher levels of activity than extraverts and so are chronically more cortically aroused than extraverts. The fact that extraverts require more external stimulation than introverts has been interpreted as evidence for this hypothesis. Other evidence of the "stimulation" hypothesis is that introverts salivate more than extraverts in response to a drop of lemon juice.[14]
Extraversion has been linked to higher sensitivity of the mesolimbic dopamine system to potentially rewarding stimuli.[15] This in part explains the high levels of positive affect found in extraverts, since they will more intensely feel the excitement of a potential reward. One consequence of this is that extraverts can more easily learn the contingencies for positive reinforcement, since the reward itself is experienced as greater.
One study found that introverts have more blood flow in the frontal lobes of their brain and the anterior or frontal thalamus, which are areas dealing with internal processing, such as planning and problem solving. Extraverts have more blood flow in the anterior cingulate gyrus, temporal lobes, and posterior thalamus, which are involved in sensory and emotional experience.[16] This study and other research indicates that introversion-extraversion is related to individual differences in brain function.
From the wikipedia entry on Extraversion and Introversion:
So I think it's fairly clear that introversion and extraversion have some genetic component. I think it's not as clear that the other preferences do.
Also keep in mind that even characteristics that have a strong genetic component are not simple on/off switches. There are often environmental influences (some of which need to be present during critical developmental periods) that affect gene expression as well.
It gets even murkier when thinking about the functions, which are not specific behaviors but rather more on the order of meta-perspectives.
"Since, in the light of these facts, the attitude-type regarded as a general phenomenon having an apparent random distribution, can be no affair of conscious judgment or intention, its existence must be due to some unconscious instinctive cause. The contrast of types, therefore, as a, universal psychological. phenomenon, must in some way or other have its biological precursor.
Although nothing would induce me to underestimate the well-nigh incalculable importance of parental influence, this experience compels me to conclude that the decisive factor must be looked for in the disposition of the child. The fact that, in spite of the greatest possible similarity of external conditions, one child will assume this type while another that, must, of course, in the last resort he ascribed to individual disposition.
Under abnormal conditions, i.e. when there is an extreme and, therefore, abnormal attitude in the mother, the children can also be coerced into a relatively similar attitude; but this entails a violation of their individual disposition, which quite possibly would have assumed another type if no abnormal and disturbing external influence had intervened. As a rule, whenever such a falsification of type takes place as a result of external [p. 416] influence, the individual becomes neurotic later, and a cur can successfully be sought only in a development of that attitude which corresponds with the individual's natural way.
-Jung
I assume MBTI follows on from that.
I've seen a few of those programs since I'm an identical twin, myself. There are some theories that twins raised together become more different in order not to compete (and to establish their own independent identities). Still, those identical twins raised apart studies do often turn up eerie similarities and parallels.
Since my twin brother is straight and conservative and I'm gay and (relatively) liberal, I will say that genetics aren't everything. Also, my twin is definitely a Thinker while I fall more on the Feeling side.
This may show somewhat of a genetic approach, but I would contend that we'd also need to know which classes each did better in. Seems small, but different subjects require different processes.
This is to Indy's comment.
identical or fraternal twins? i'm under the impression that being gay is a biological thing, and not a choice. so i'm thinking you two are most likely fraternal twins.
I am an identical twin. If one identical twin is gay, there is about a 50% chance (varies a bit depending on the study) that the other twin is gay. That's highly statistically significant, but not 100% deterministic.
Some theorize that hormone levels in the womb are also involved—for example, one's chances of being gay (if you are male) go up the more older brothers you have that share the same birth mother, even if you aren't raised with them.
I agree that sexual orientation can't be changed (at least in the vast majority of cases), but that doesn't mean it's always 100% genetic.
I know very little on genetics, but I imagine with twins it's very dependant on embryo division and if the twins were divided similiarly. I think with the video 'Seperated Twins' this may be apparent in their metabolisms, of course we aren't given any information about their previously lives only that they acted similiarly within in the different families, but if they acted similiarly but appear different something is different between them. I don't know this is what came to mind when watching.
that's really interesting. so what you're getting at, is that most likely it is the hormone levels in the womb that created the difference between you two?
i'm no science buff, so i can't say i know for certain how all of this works or comes into play.
Jung would have learnt from Freud that the same childhood traumas could lead to different symptoms in different people. but yous till can't seperate the symptom from the trauma. Its neithe rpurely nqature nor nurture, nor a balance. Rather an interaction.
Fair enough if you want to believe Jung dude, there's no mroe "proof" of my view than yours. But Jung's view just seems like a simplification when more viable theories had already been proposed.
I agree that it is an interaction, to me finding your "natural" type is an attempt to peel back those environmental influences. You can probably never do it completely but from a self development perspective whether it is genetic or happened in early childhood I believe it's entirely possible to be raised as say an ENTJ yet still have a "natural" preference for ISFP. Just as you can be raised as a righthander even though you are "naturally" left handed. You can write with both hands but one will feel more natural/comfortable/fulfilling.