The larger sized amygdala of cab drivers would fit right in with what I said about pattern recognition. An experienced cab driver would certainly not logically solve how to negotiate every shift in traffic as it happens.

My post is not taken directly from any single abstract, but is my conclusions based on the findings of a number of studies. I first became interested after reading an article about differences in the brains of liberals and conservatives. I tracked down the study and read it. While I don't agree with their conclusions, and find the way they structured the study to be wanting; there is some good data to be found. https://www.sciencedaily.com/releases/2013/02/130213173131.htm

Then I sought out a more scientific abstract which didn't appear to be done with preconceived political bias. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3092984/

And here is a study on the size differences of right and left amygdala, and other brain structures. While nothing in the study mentions political ideology, I noted that the articles regarding size differences of liberals vs conservatives described the same differences as this one for age. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3633516/

While this study was not focused on political ideology, it is very useful as it indicates a definite correlation between psychological differences in people and the differences in their amygdala. https://www.ncbi.nlm.nih.gov/pubmed/28689329

This article is not an abstract but an article written by a top pioneering neuroscientist regarding his work and the common misinterpretations. https://www.psychologytoday.com/us/blog/i-got-mind-tell-you/201508/the-amygdala-is-not-the-brains-fear-center

Within a Wikipedia article on the amygdala, I've copied out two snippets I find interesting. "Social interaction
Amygdala volume correlates positively with both the size (the number of contacts a person has) and the complexity (the number of different groups to which a person belongs) of social networks.[64][65] Individuals with larger amygdalae had larger and more complex social networks. The amygdala is responsible for facial recognition and allows others to respond appropriately to different emotional expressions.[66] They were also better able to make accurate social judgments about other persons' faces.[67] The amygdala's role in the analysis of social situations stems specifically from its ability to identify and process changes in facial features. It does not, however, process the direction of the gaze of the person being perceived.[68][69]

The amygdala is also thought to be a determinant of the level of a person's emotional intelligence. It is particularly hypothesized that larger amygdalae allow for greater emotional intelligence, enabling greater societal integration and cooperation with others.[70]"

And
"Political orientation
Amygdala size has been correlated with cognitive styles with regard to political thinking. A study found that "greater liberalism was associated with increased gray matter volume in the anterior cingulate cortex, whereas greater conservatism was associated with increased volume of the right amygdala." These findings suggest that the volume of the amygdala and anterior cingulate gyrus may be associated with an individual's ability to tolerate uncertainty and conflict.[86]"

So a larger amygdala allows for greater social interactions and is associated with conservatism. Of course that is extremely simplistic, but not inaccurate. https://en.wikipedia.org/wiki/Amygdala

I can't remember where else I've read studies regarding the amygdala. I know there was another regarding size and age broken down into a number of age groups, yet not as in depth as the one I included. But I'm afraid I've misplaced the site.

Depends on what age the person is. The amygdala grows larger with age. And the left and right do not seem to grow at the same rate. There is a definite difference in growth between a man's and woman's with one developing the right more and the other the left (I'd have to look up which is which). A person's experiences might also effect the rate of growth if you look at the studies showing children who have experienced trauma have larger amygdalas. Maybe the more rapid growth under trauma is like a muscle developing more when used more. A couch potato having less muscle than a weight lifter is perfectly understandable. Maybe the same is the case with the amygdala that exercising it causes it to grow faster. This would correlate with the more rapid and effective response to potential threats by those who face those potential threats more frequently, which amygdala activity to threats documented under MRIs has been associated with. By potential threat I don't just mean attacks but dealing with situations where poor or slow choices can put you in danger or give poor performance outcomes such as with the taxi drivers or many sports. I would bet that if amygdalas of race car drivers were scanned under MRIs, they would be larger than the average for their age.

So there is no standard size across the board. Again if comparing it to muscles, what would the standard size of biceps of humans? Wouldn't you say that would depend on what age, sex, and activity of the person?

I got through a portion of it . so much bull dung I thought I was going to drown in crap . if President Trump is a r****t because he wants immigrants to come into this country legally . then the writer of this article may be a r****t . he has NEVER made a statement to keep muslims out of America . he does not deny any Hispanic from coming to America . just do it the proper way . -----regs. that were cut were usually doubled or tripled regs. concerning the same point . ----tax cuts , yes he did cut taxes on the corp. side . he also cut out some of the deductibles . I know I lost several deductibles . there was also a tax cut for working people . and a increase of some deductibles for children . ---- if per chance the far , far ,right v**ed for Trump , then I would venture to say that sense the far , far left v**ed for obumer, then he is a r****t . --- open boarders ? why is it that the dems. and the left want open boarders? to build a new v**er base ? they say it is immoral , to not ecept others . yet when President Trump , suggested sending them to sactuary cities and states . oh no you cant do that . ------ reality TV. syndrome I don't watch that crap . I v**ed for Donald J. Trump , BECAUSE he seemed to be the only candidate who gave a ____ about our country . the people who live ,work , protect , serve and love this country . not some run of the mill political figure head to help bring about the end our country . --------head dr. have done some fantastic work . but I also blame them as part of the down fall of the American society . our prisons are full of young men and women . who have been brought up in households where there was no or very little discipline . thinking that they can do as they darn well please and to _ _ _ _ with what any one thinks or says . no consequences for their actions . now their sitting in prison because of that . I could go on and on arguing with that persons line of BULL DUNG . but it would be a enormous waste of time .

..
Yes, and more---genetics, temperament, culture, and personal history, which all may be affected by neural processes. It would take a huge data base (and an awfu lot of fMRI time) to account for these things even if you could consider them static. But then, if the size of the amygdala is dependent on political leaning, how to build into the model an accounting of the change in one's political leanings--which are not always the static of left when young and right when old? I was raised in an Orange County-like county in the Midwest, grew up reading Leonard Reed and the FEE materials, and believed in the theories of Hayak and von Mises. Many decades later I find that they do not answer the problems of where the US is in the cycle of the evolution of republics (Polybius, Aristotle, Adams, or even Strauss/Howe). So a possible lifetime-changing paraneter like personal history has to be considered. That is a worthy lifetime problem for you to pursue, JoyV!
So, maybe today the correlation of amygdal size with political leaning is no better than psychbabble; tomorrow, who knows.

Maybe we should be thankful that there is no such data that a tyrannical despot could use to evaluate one's politics or loyalty based on the size of one's amygdala. After all, despots can arise on both the left and the right.

Yes. This is far from the simple conclusion the first study reached that if you are a liberal you have a normal sized amygdala (how do they know what is normal), and if a conservative you have an a******lly large amygdala. None of the studies can come close to covering all the possible variables. But the one dealing with political leanings would not have accepted by my high school science teacher for being so flawed. (By flawed I don't even mean conclusions but by not doing anything to try to isolate variables.

No this is too big for me and I am just a layman science (biology/genetics) buff.