In the second and final chapter of this series, we review evidence that commenter Tez has high IQ. From his email:

……………………………………………………………………………………………………………………………………………………………………………

1. My mother and I are the only obese people in our extended family, and we both used to be quite thin. The general trend of genetic stock is fairly promising on my mother’s side of the family tree, where almost everyone is thin, or at least was thin prior to middle age. My father’s family history is mysterious but he was rail thin and very tall, suggesting high IQ. Also, I was in great shape for most of my life. I gained 50 lb in the past 6 years during a prolonged depressive spell, then gained another 20 lb during lockdown.
2. My childhood IQ was 139. I don’t know what the intelligence scale of the test was. I suspect it was Wechsler but 139 is high by any standard, particularly for an underclass kid. Incidentally, I was forced to take an IQ test by my kindergarten teacher. She assumed I was retarded after I failed a simple busy work assignment to draw a mode of transportation (airplane, bike, car, etc.) Possessing a creative spark, I drew an enormous catapult with a passenger seat for a parachute equipped traveler. Tangentially, I tend to agree with your theory that childhood IQ scores are more reliable, although I am obviously biased by my own high score.
3. I learned to speak at a very young age and was speaking in complete sentences before my second birthday. At the age of one, I apparently told my mother I intended to learn how to potty train myself as it would spare her the trouble of teaching me. I have no memory of this conversation but see no reason for my mother to lie about it.
4. I am 6’5″. That is tall for any ethnic group but extremely tall for someone who is part Japanese. My mother is tall for a half Scottish, half Japanese woman at 5’8″ and my father was a 6’2″ French Canadian. Interestingly, everyone on both sides of my family has scoliosis, including my mother who has double scoliosis, meaning her spine is shaped like the letter S. Even in her 70s, I suspect she’d be well over 6’0″ if she could straighten herself out. I would probably be 6’8″ or so if I could straighten out my back but I’m already too tall for comfort.
5. I have an enormous skull, with a head circumference of 25.5″ or 64.77cm. Whether or not this evinces a superior brain is up for debate.
6. I am extremely pale, even adjusting for ethnic background. People have always made comments about my paleness, which I find insulting and inappropriate. In any case, my great paleness suggests to me that my ancestors all lived in very selective environments.
7. My maternal (Japanese) grandfather was highly intelligent, long lived and the direct descendant of nobility. My mother’s father was an MIT educated electrical engineer who worked alongside Albert Einstein on various projects for the Department of Defense. My grandfather definitely knew Einstein as evidenced by his photo of them working together in a lab. What I am less sure of is my grandfather’s claim to have corrected several of Einstein’s equations. After leaving the DoD, my grandfather worked for NASA monitoring sounds from outer space. He eventually died at the age of 95. The cause of death was pneumonia, which he could have treated but instead he simply chose to die. He seemed to follow Einstein’s sentiment that it was inelegant to fight the inevitable. For all I know, Einstein picked up that sentiment from my grandfather. The Japanese are fairly stoic about facing death, particularly those descended from samurai stock. In any case, although he was 95 at the time of his death, he could have lived even longer and that suggests excellent genes.
8. My great grandmother was said to be one of the tallest women in Japan. She wasn’t tall by contemporary western standards but as a woman in the 19th century, standing 5’6″ made her a veritable giantess. She was also the daughter of samurai.
9. My maternal grandmother was supposedly highly intelligent. Personally, she always struck me as a first class idiot and religious fanatic. She also appeared to be an untreated schizophrenic but her measured IQ score was 150. She died at the age of 84 from heart failure. I suspect she could have lived another ten years had she spent less time praying and more time exercising. She was rail thin but that seemed to be more from living on a low calorie diet.
10. My mother’s childhood IQ score was 158. I don’t know what test she took, however, and in general, am not convinced my mother is all that bright. I suspect the lion’s share of intelligence related genes went to her younger sister, who got two masters degrees, climbed the corporate ladder and married a member of Bill Clinton’s cabinet.
11. Even though he was eventually expelled, my father was smart enough to attend Harvard. Simply getting accepted is fairly impressive in light of his white trash upbringing. It’s interesting to note that when he attended, the acceptance rate was closer to twenty percent than its current rate of three percent despite the student body remaining the same size. This is because Harvard spends millions of dollars annually tricking high school seniors with no chance of admission into applying simply so Harvard can sate its elitist need for exclusivity by denying more applicants. Thus Harvard, with its ultra low acceptance rate, can maintain its spot among the ranks of US News’ top colleges in America. Elitism for the sake of elitism; how typical of the ivy league caste system.
12. Despite putting no effort into it, my SAT score was a respectable 1220 out of a possible 1600. I can’t stress enough how little I actually cared about school growing up. I certainly had no intentions of attending college. My plan as a teenager was to become a comic book artist, possibly after attending cartooning course at a trade school like the Kubert School in New Jersey. My teachers and guidance counselor kept hounding me to take the SAT, so I took it to get them off my back. I treated it like an eye exam, walking in off the street with zero prep and going through the motions. It literally never occurred to me to study given that I had never studied for a test in my life. In spite of this haphazard approach and a piecemeal education, I did quite well. Also, family income correlates perfectly with SAT score and adjusted for my family income bracket–less than 20k a year–I scored off the charts.
13. People frequently comment that they are impressed if not astonished by my intelligence. Personally, I take this as something of a back handed compliment as I believe it evinces a prejudice against hulking giants. I look like a 6’5″ Ron Livingston with the physique of James Gandolfini–broad shouldered with a block shaped torso. People expect you to be dumb when you’re built like an NFL lineman. Conversely, people online who have no idea what I look like frequently compliment my intelligence. Of course, in so doing, they are merely comparing me to the average internet pleb, which isn’t saying much. Still, it is worth noting that my college classmates revered me as a literary demigod and constantly requested my guidance overseeing their term papers.
14. I suspect I have fairly high emotional intelligence, if that is truly a thing. Despite constantly moving around from school to school, I was always very popular and in some cases had what can only be described as a cult like following of adoring vassals. People tended to hang on my every word when I would hold court on various subjects of interest. I completely took this for granted when I was younger. Only recently have I appreciated this was remarkable adjusted for circumstances. My third grade teacher kept telling my mother, “Your son has such amazing charisma for his age. He could be president one day.” I don’t entirely agree but politics don’t interest me in any case.
15. I have a borderline eidetic memory, for whatever that is worth. I didn’t realize this was a gift until I was in my early 20s. Naively, I assumed everyone remembers things with near crystal clarity. How wrong I was.
16. I am a fairly talented artist, particularly by the standards of an autodidact. I am also a competent video editor, photoshop enthusiast, essayist and writer of short stories. Currently I am working on a novel set in Afghanistan.

Other relevant info:

Miscellaneous labels I identify with: Atheist, secularist, transhumanist, INTJ, politically liberal (voted Green Party in past two elections), unmarried, no kids, night owl, teetotaler, art and music lover.

Hobbies: I hate sports with the intensity of a thousand suns. I love strategy games like chess and Magic: The Gathering, both of which I have played at a ranked competitive level. I play poker semi-professionally and have done well for myself. My musical taste is eclectic; I like almost everything but hate country and most rap music. I love film and was dumb enough to major in it back when I still fantasized about a career as a director. Sam Harris is my favorite living non-fiction writer, though I also have a lot of respect for conservative intellectuals like Thomas Sowell who challenge liberal conventions. I was a fan of Chomsky in my early 20s but now cringe at his overly simplistic world view, which appears to be motivated in part by ethnic genetic interests. I don’t watch a lot of TV but I love Bill Maher and occasionally enjoy Rachel Maddow. Norm MacDonald was my favorite comedian and I’m heartbroken by his passing.

One other random fact: I am only attracted to women with brown skin, dark hair and brown eyes. I seem to be attracted to my total opposite given that I am pale skinned, green eyed and prematurely white haired (I dye it black). I don’t know if this attraction towards brown skinned women says anything about my IQ. I interpret it as nature attempting to give my unborn offspring a chance at enduring the unforgiving summers global warming has thrust upon us.

Well, hopefully you are still awake after reading all of that, generously assuming you read any of it.

If you have any follow up questions, let me know.

……………………………………………………………………………………………………………………………………………………

Tez has provided an enormous amount of information so I’m just going to simplify by focusing on the most salient.

BIODEMOGRAPHICS

As I mentioned in part 1, the average IQ of a chronically American is 81 (U.S. white norms). Average IQ of a 6’5″ quarter Japanese White American Millennial man is 111. Average IQ of a white American Millennial man with a 25.5″ head circumference is 116.

What is the average IQ of someone with all three characteristics? To answer that question, we do not simply average the three averages because the traits are imperfectly correlated. The actual expected IQ of such a person is 92 (U.S. white norms). The reason it’s so low is chronic unemployment is a much more powerful IQ predictor than physical traits like height and head size, especially since the latter are substantially correlated and thus add little information independent of one another.

With his slight Mongoloid tilt, colossal physique, and chronic unemployment I am picturing a dim-witted giant, like Chief in One Flew Over the Cuckoo’s Nest. I find it fascinating that Tez wrote “People expect you to be dumb when you’re built like an NFL lineman” but I’m wondering if his height adds, or subtracts from the impression of stupidity.

PSYCHOMETRICS

And yet Tez scored 1220 on the re-centered SAT which at the time he likely took it (early 2000s), equated to an IQ of 123 (U.S. norms); about 121 (U.S. white norms). And if anything this is an underestimate given Tez’s poor schooling (although quality of schooling tends to correlate with genetic quality).

So bio-demographics underestimated Tez’s IQ by roughly 2 standard deviations! I guess this is expected given the huge standard error on predictions based on IQ correlates as crude as employment, height and head size, but error might be especially large for someone like Tez, who has come from such an unusual background. It may also have been a mistake to use chronic unemployment as a predictor when he admits to working “under the table” especially if he makes a lot of money doing so.

Until more in-depth testing occurs, I will adopt 121 as the best measure of Tez’s IQ.