Neuroanatomy of the MBTI

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ChatGPT came up with this after much prompting. I know nothing about neuroanatomy, so take this essay as speculative at best.

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Mapping Myers–Briggs onto the Brain: A Neuroanatomical Take on Cognitive Functions and Personality Dynamics

The Myers–Briggs framework posits that our personality is built from two core pairs of cognitive functions - Sensing versus Intuition (S/N) and Thinking versus Feeling (T/F). These are the very processes through which we gather data and make decisions.

But Myers–Briggs isn’t merely a list of traits; it describes a dynamic hierarchy. Depending on one’s type, either a perceiving function (S or N) or a judging function (T or F) sits at the top, with the other assuming a supportive, auxiliary role. (Notably, if your dominant trait is perceiving, your auxiliary is judging - and vice versa.) This dynamic interplay, along with a less-developed tertiary function and a shadow (inferior) function that surfaces under stress, is what Myers–Briggs type dynamics is all about.

Yet, this phenomenological theory can be enriched by looking beneath the surface - to the neural networks that give rise to these cognitive styles. All four functions are mediated by the neocortex, but they differ in their neural “wiring”. 

For instance, Sensing types rely more on primary sensory cortices and lower-level association areas that capture concrete detail. In contrast, Intuitive types engage broader, integrative neocortical networks, enabling abstract pattern recognition and the drive for intellectual cohesion.

Likewise, the Thinking function correlates with robust activity in the dorsolateral prefrontal cortex - our analytical, systematizing hub - while the Feeling function draws more heavily on limbic-influenced regions (such as the ventromedial prefrontal cortex and anterior cingulate), where emotional and social signals merge with higher reasoning.

The next layer of the MB model involves the Extraversion/Introversion (E/I) and Perceiving/Judging (P/J) dichotomies, which determine which of these core functions emerges as dominant in everyday life. 

Extraverts “broadcast” their dominant function, driven by dopaminergic reward circuits in areas like the nucleus accumbens and medial orbitofrontal cortex that energize approach behavior. Introverts, with their higher baseline arousal and stronger inhibitory control from regions like the dorsolateral prefrontal cortex, tend to keep their dominant process internal - thus often expressing their auxiliary function in social settings.

Similarly, the P/J dimension shapes our external engagement. Judging types crave order and closure - a tendency that may reflect tighter, more resolute connectivity in executive circuits that quickly resolve uncertainty. Perceiving types, conversely, show a greater tolerance for ambiguity, their neural architecture perhaps more geared toward continuous information gathering and flexible, open-ended processing.

By situating Myers–Briggs’ phenomenological narrative in the concrete language of brain anatomy, we see a richer picture emerge. Our cognitive functions aren’t rootless abstractions but emergent properties of distinct neural networks.

The S/N and T/F axes provide the basic cognitive “tools,” while the E/I and P/J dimensions determine which tool comes to the fore, and how. In this way, personality is not simply a set of descriptive labels - it is a dynamic interplay between ancient limbic impulses and modern cortical control, a multilevel tapestry underlying human behaviour.