Neuropolitics: “Openness” and Cortical Thickness

Brain anatomy–gyruses

I ran across an interesting study today, on openness, creativity, and cortical thickness.

The psychological trait of “openness”–that is, willingness to try new things or experiences–correlates with other traits like creativity and political liberalism. (This might be changing as cultural shifts are changing what people mean by “liberalism,” but it was true a decade ago and is still statistically true today.)

Researchers took a set of 185 intelligent people studying or employed in STEM, gave them personality tests intended to measure “openness,” and then scanned their brains to measure cortical thickness in various areas.

According to Citizendium, “Cortical thickness” is:

a brain morphometric measure used to describe the combined thickness of the layers of the cerebral cortex in mammalian brains, either in local terms or as a global average for the entire brain. Given that cortical thickness roughly correlates with the number of neurons within an ontogenetic column, it is often taken as indicative of the cognitive abilities of an individual, albeit the latter are known to have multiple determinants.

According to the article in PsyPost, reporting on the study:

“The key finding from our study was that there was a negative correlation between Openness and cortical thickness in regions of the brain that underlie memory and cognitive control. This is an interesting finding because typically reduced cortical thickness is associated with decreased cognitive function, including lower psychometric measures of intelligence,” Vartanian told PsyPost.”

Citizendium explains some of the issues associated with too thin or thick cortexs:

Typical values in adult humans are between 1.5 and 3 mm, and during aging, a decrease (also known as cortical thinning) on the order of about 10 μm per year can be observed [3]. Deviations from these patterns can be used as diagnostic indicators for brain disorders: While Alzheimer’s disease, even very early on, is characterized by pronounced cortical thinning[4], Williams syndrome patients exhibit an increase in cortical thickness of about 5-10% in some regions [5], and lissencephalic patients show drastic thickening, up to several centimetres in occipital regions[6].

Obviously people with Alzheimer’s have difficulty remembering things, but people with Williams Syndrome also tend to be low-IQ and have difficulty with memory.

Of course, the cortex is a big region, and it may matter specifically where yours is thin or thick. In this study, the thinness was found in the left middle frontal gyrus, left middle temporal gyrus, left superior temporal gyrus, left inferior parietal lobule, right inferior parietal lobule, and right middle temporal gyrus.

These are areas that, according to the study’s authors, have previously been shown to be activated during neuroimaging studies of creativity, and so the specific places you would expect to see some kind of anatomical difference in particularly creative people.

Hypothetically, maybe reduced cortical thickness, in some people, makes them worse at remembering specific kinds of experiences–and thus more likely to try new ones. For example, if I remember very strongly that I like Tomato Sauce A, and that I hate Tomato Sauce B, I’m likely to just keep buying A. But if every time I go to the store I only have a vague memory that there was a tomato sauce I really liked, I might just pick sauces at random–eventually trying all of them.

The authors have a different interpretation:

“We believe that the reason why Openness is associated with reduced cortical thickness is that this condition reduces the person’s ability to filter the contents of thought, thereby facilitating greater immersion in the sensory, cognitive, and emotional information that might otherwise have been filtered out of consciousness.”

So, less meta-brain, more direct experience? Less worrying, more experiencing?

The authors note a few problems with the study (for starters, it is hardly a representative sample of either “creative” people nor exceptional geniuses, being limited to people in STEM,) but it is still an interesting piece of data and I hope to see more like it.


If you want to read more about brains, I recommend Kurzweil’s How to Create a Mind, which I am reading now. It goes into some detail on relevant brain structures, and how they work to create memories, recognize patterns, and let us create thought. (Incidentally, the link goes to Amazon Smile, which raises money for charity; I selected St. Jude’s.)


3 thoughts on “Neuropolitics: “Openness” and Cortical Thickness

  1. I bought that book, I think from your last post.

    That is interesting. Of course I am no neuroscientist and I don’t know the full extent of the studies and such. But I do get a sense of the limitations placed upon the interpretation just from your report.

    Perhaps The thickness of that Larry could indicate more of a brain’s ability to establish and maintain limitation. Not necessarily that it is more intelligence or lens to more intelligence or lands to greater ability for intellectual capacity or anything like that… Because said intellectual capacity and such really would just be sub categories of the brains capacity to inform limitation and abide by it.

    I do like how you associate creativity with the capacity to have more direct experience, as opposed to contemplative knowledge perhaps. But I would have to ask what is this direct experience ? Direct experience of what?

    I see a hint in just the category of creativity. Because again, what is creativity?

    Perhaps creativity and its counterpart, I don’t know, intellect or knowledge, maybe, it’s just one way of talking about limit that the brain places upon a person’s capacity to have experience of a world. Which is to say what we associate his creativity could actually mean a brains capacity to have a larger world or world involved with more variation of aspects, Where as the counterpart to that would be the brains ability to shut down and limit and confine and systematize and have a smaller coordination or smaller Library of aspects.



    • Thank you. I hope you enjoy the book. Kurzweil thinks that these cortical areas are basically pattern recognizers. So maybe some people get locked into recognizing a particular set of patterns, while other people don’t. And if you aren’t locked in, maybe you can have more new ideas. You aren’t being held back by what you already know.

      Direct experience: some people do seem to just experience the world more strongly than others. Like, in one experiment, researchers put drops of lemon juice on people’s tongues and measured how much they salivated in reaction; the introverts salivated more. “Introverts experience physical stimuli more strongly than extroverts and thus react more and thus withdraw from experience more because it is more overwhelming,” seems like a reasonable theory. Some people seem very moved and affected by books they read or music they listen to, while others aren’t.

      Have a great day.

      Liked by 1 person

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