Dyslexia and hyperlexia: hunter-gatherer brain phenomena

In an online Michael Heart points out that hyperlexia and dyslexia might actually be two sides of the same coin. I am particularly interested in these phenomena as one of my children was hyperlexic as a toddler and was able to read fluently around age 2. Motivated by his interest and passion for reading I set out to teach my other children reading. I was successful with my second son, who learned to read around age 3. However, I utterly failed with my daughter, who even after reading literally hundreds of books with me did not show any reading ability by age 5.

  • putting letters and figures the wrong way round (such as writing “6” instead of “9”, or “b” instead of “d”)
  • Writing those letters the wrong way round
  • confusing the order of letters in words
  • Trying to guess a lot of words from context
  • Distractedness (moving eyes around on the page)
  • reading slowly or making errors when reading aloud

In my model of evolutionary personality types, I have associated dyslexia with high risk for hunter-gatherer (intuitive in Myers-Briggs/MBTI) types. From my experience as a teacher, I know that kids with dyslexia also often have ADHD, which Thom Hartmann first identified as a “hunter” trait. In fact, up to 40% of children with ADHD also have dyslexia and there seems to be even a considerable genetic overlap.

What made me establish this connection between hunter-gatherer minds and dyslexia. Let’s have a look at some of the strengths of dsyslexic people (unfortunately we tend to focus too much on the weaknesses of neurodiverse kids)

  • Seeing the bigger picture (intuitive in MBTI)
  • Good pattern recognition and memorization (intuitive in MBTI)
  • Good spatial skills (T in MBTI)
  • Picture thinkers (T in MBTI)
  • Highly creative (N/P in MBTI)
  • Business entrepreneurs (EXXP in MBTI)
  • Sharper peripheral vision (N? In MBTI)

Assuming you believe somewhat in the validity of MBTI, the pattern that emerges is that ENTP (hunter) types are most at risk for dyslexia and ADHD. These people also make up some of the most successful and visionary business entrepreneurs, like Sir Richard Branson .

It isn’t anything but obvious why these traits should be hunter-gatherer traits, with the exception of the last one: better peripheral vision. It’s easy to see how this was evolutionarily advantageous for hunter-gatherer types in their foraging activities, whereas early farmers likely evolved a more focussed vision, beneficial for long rote farming tasks. Peripheral vision might also provide a cause for the problems hunter-gatherer type children may have: it they take in more information from the periphery and are more distractible (ADHD) you might easily get the phenomena familiar from dyslexic children: swapping letters, mixing up letter sequences and a higher distractibility in general (e.g. from pictures on a page).

If hunter-gatherer children are different from farmer children, it should be expected that other kids share similar developmental trajectories as gifted kids. Right from the moment when my son started to read around age one I was both delighted and worried. I had read about a symptom called “hyperlexia”, that is quite common in children with ASD, just as common as in children who are gifted. The difference, hyperlexia in children with ASD is often accompanied by learning problems (surprisingly also verbal) whereas hyperlexic kids without ASD are generally bright.

Darold Treffert distinguishes between three types of hyperlexia:

  • Neurotypical hyperlexia, i.e. gifted or precocious children
  • Hyperlexia in ASD children
  • A mixed type that shows signs of autism and then continues to develop in an NT way.

Interestingly it looks like type 3 is on the way to developing autism and then takes the trajectory of type one. I think all three cases are most likely to be found in hunter-gatherer type children that take different trajectories. Even though a lot of ASD people favour a strong genetic causality for ASD, I personally favour the hypothesis that all of these trajectories are more dependent on (perhaps just subtle) differences in the environment.

At the time I tried to get answers to the question if my son was more likely autistic or gifted or both by even writing to the world-renowned autism researcher Simon Baron-Cohen. However, nobody could really give me an answer. I just had to wait. Fortunately, my son didn’t show most of the typical struggles of autistic children. He even developed an acute sense for puns, his favourite type of humour.

Why did my son learn to read so early while my daughter struggled with it? It may well be due to another hunter-gatherer phenomenon: hyperfocus. From year 1 my son was interested in letters, learned their names within a week and generally focussed on symbols wherever he saw them (letters, numbers, crossed, etc.). This kind of hyperfocus is well known in both gifted children and children with ASD. In brief, my son learned to read because his brain found letters interesting, whereas my daughter didn’t because her brain found the things around the letters (e.g. pictures) more interesting. My daughter is also very extroverted, therefore more focussed what is going on in her environment, my son is very introverted and more often more interested in what is going on inside his mind.

Putting it all together: neurodiverse people with hunter-gatherer genes (N in MBTI) are at a higher risk for certain neurodevelopmental problems like dyslexia, ADHD and autism while at the same also be among gifted children who learn to read as early as two years old. This would explain why there are so many twice-exceptional (2e) children, gifted children with a “disability” like ADHD, ASD or dyslexia. The personality dimension also shows in the fact that children with ADHD (impulsive or mixed) are more often extraverted (ADD — introverted) and children with ASD introverted. Also, all people who were early readers I know personally are introverts. It is unclear if children with dyslexia are more often extroverted, however. Studies have shown no big personality differences between dyslexic and non-dyslexic children.

Originally published at http://the-big-ger-picture.blogspot.com on December 14, 2020.