Neurodiversity Part 7:
As mentioned in Part 2, human behavior research into introversion and extroversion does not align with the public view of these terms. It isn't culled down to how shy or outgoing a person is. And the research dating back to brain scans in the 1960's and 70's shows similarities to the public definition of neurodiversity (coined in the 1990's by Judy Singer.)
Part 3 looked at blood flow in the brain.
Part 4 went over cortical arousal.
Part 5 discussed anticipatory reactions.
Part 6 looked at behavioral systems.
This section will go over a baseline model for neurodivergence. Part 8 will look at how that baseline model relates to diagnoses like ASD and ADHD.
Also, here is a link to the seven executive functions listed in a Psychology Today article for reference.
Baseline Model of Neurodivergence
It’s important to keep in mind that a person’s personality is based on their biological processes, their psychological adjustments, their environment, as well as normal fluctuations (such as hormones, health, sleep and eating routines, stress, and relationships to name a few.) So personality isn't necessarily seen as concrete or permanent.
But let’s talk about how the research mentioned in this series can help explain physiological systems that may explain the biological side of a person’s mindset. (I won’t be referencing the blood flow section here as I would likely misinterpret several highly integrated functions of the mind.)
I'd also like to include H Fisher's Builder and Explorer personality traits due to their basis on the serotonergic and dopaminergic systems. The traits she outlines also correlates with language differences (concrete vs. abstract) mentioned in Part 3 and behavioral system differences (inhibition vs. activation) mentioned in Part 6. I will be referencing her Negotiator and Director personalities in a separate article.
IMPORTANT NOTE: If a person has higher cortical arousal and serotonin deficits, it can lead to dopamine seeking behaviors such as impulsivity, hyperactivity, addictive habits, and trouble with emotional control. These traits are most often seen in ADHD, but other diagnoses may include them as well. (Higher cortical arousal can be seen in the ADHD marker test looking at involuntary eye movement.) Serotonin is important for modulating cortical arousal, mitigating ADHD symptoms, and regulating emotions and sleep. We will discuss this more in Part 8. But this is why ADHD can still fall under the research definition of introversion (higher cortical arousal, dopamine differences, etc.) even if they're more outgoing.
Finally, I'd like to propose some new terminology for the research behind these traits for the following reasons:
- The terms introversion and extroversion are already heavily correlated with sociability. So progressing under those terms would likely cause confusion.
- “Neurotypical” inherently implies that one mindset is more "normal" or "correct" than another.
- The characteristics I'm going to outline below will likely encompass a larger portion of the population than just those who may qualify for or are already diagnosed with ASD, ADHD or otherwise. I'll discuss this more in part 8.
- But most importantly, the term "neurodiversity" is important to the Actually Autistic community. I don't want to undermine the experiences that are especially relevant to autistic individuals: part of the traits associated with ASD have to do with other personality systems as well, possibly related to oxytocin and vasopressin, that create the diverse outlook the community has. And I can imagine from what I've heard and seen that it can be frustrating when people generalize or invalidate autistic people's experiences with phrases like, "What if everyone's a little autistic?" I don't want to do that by proposing broader personality traits (which is what the biological basis of introversion and extroversion already do) and trying to fit it under the term "neurodiversity." Also, if new research arises that changes anything I've outlined in this series, I don't want it to change the core meaning of "neurodiversity" either. We've seen how easily the public definition of introversion separated from the research definition. And autism research is finally addressing some of the inherent issues of past studies. So I don't want to create groundwork for other stigmas to arise or that takes away a naming convention that is particularly important for the Actually Autistic community. Neurodiversity though is an important subset of the following neurotype (Neurotype I.) Neurodiversity can still be used interchangeably with Neurotype I. But unless the Actually Autistic community chooses to incorporate the information in this series, I don't want to take anything away from them.
(Research Definition of Introversion / Neurodiverse / Fisher's Builder Personality)
- Does the person tend to have higher cortical arousal? (Mind is stimulated more naturally by acetylcholine, may process stimuli faster, thoughts may race, can get overstimulated or have trouble shaking hyper-focus in times of stress.)
- Does the person prefer concrete details over abstracts in conversations? (Preference for less ambiguity, straightforward approach, someone saying outright what they want or how they feel, gives more consideration to facts over interpretations.)
- Is the person sensitive to polychronic time? (Minutes and hours feel untrackable without timer, can get lost in a task, prefers to multitask.)
- Is the person more motivated by tangible rewards? (Need to know or see end results, may feel dread instead of excitement while anticipating something, have trouble accomplishing long-term goals without milestone rewards.)
- Does the person lean more toward serotonergic traits versus dopaminergic ones? (Per Fisher's Builder personality: cautious, persistent, loyal, fond of rules and facts, and orderly.)
- Is the person overly sensitive to negative outcomes? (May be less impulsive and may rely more on aversive motivation to avoid punishments, negative situations and feeling bored.)
- Does the person struggle more in the absence of serotonin versus the absence of dopamine? (May experience anxious episodes, have trouble controlling emotions, and struggle with stepping away from a hyper-focus.)
(Research Definition of Extroversion / Neurotypical / Fisher's Explorer Personality)
- Does the person have lower cortical arousal? (Seek out external engagement to stimulate mind by dopamine, can find hectic environments energizing, may feel lethargic otherwise.)
- Does the person prefer abstracts in discussion and feel adept at interpreting abstraction? (Doesn't mind ambiguity, dancing around a difficult topic, or implying things, gives more consideration to interpretations over facts.)
- Does the person prefer monochronic time? (Takes time commitments seriously, strictly adheres to plans, prefers to do one thing at a time.)
- Is the person sensitive to abstract rewards or anticipation? (May be able to read between lines or anticipate a reward without it being spelled out, can feel invigorated and compelled by anticipation, find things like social validation motivating.)
- Does the person lean more toward dopaminergic traits vs serotonergic ones? (Per Fisher's Explorer personality: propensity to seek novelty, willingness to take risks, spontaneity, heightened energy, curiosity, enthusiasm, flexibility.)
- Does the person actively seek out positive experiences? (May be more impulsive and exhibit approach or exploratory behavior, experience appetitive motivation to seeking reward.)
- Does the person struggle more in the absence of dopamine versus the absence of serotonin? (Struggle with a lethargic depression, lack of appetite or prior interests, seeks out risky behavior, act impulsively, or chase an addiction fix.)
The next section will look at how ASD and ADHD diagnoses have compounding factors on top of the baseline Neurotype I traits.