Despite being raised in the projects, shooting his brother at age 12, dropping out of high school, and being accused of stabbing, self-described “thug” Jay Z used his incredible IQ to build an empire.

I’ve blogged about rapper Jay Z’s childhood reading level before, but in light of what I’ve since learned about reading levels, it seems I might not have done his score justice.  In 2009, Jay Z had the following exchange with Oprah:

Oprah: How were you in school? I’ve heard that when you were in sixth grade, you tested at a 12th-grade level.

Jay-Z: I was bored and distracted.

Oprah: Did you like anything about school?

Jay-Z: I loved English.

Oprah: I know you love to read now. Were books part of your childhood?

Jay-Z: No. I don’t remember that.

Oprah: And I thought we had so much in common!

Jay-Z: I just daydreamed a lot.

Oprah: What about?

Jay-Z: Performing or playing baseball and basketball. I took my mind out of my environment, to the point where I wasn’t paying attention to what was happening around me. I still do that now.

Oprah: You didn’t listen in class, you didn’t read books—and you still tested as a 12th grader. You must have a naturally high IQ.

Jay-Z: Or I’m an idiot savant.

Of course you can’t believe everything you read, especially about public figures, but in the case of Jay Z’s childhood reading level, his sixth grade teacher, Renee Lowden said:

He never smiled, but when he did, he’d light up the room for me…He was reading at the 12th grade level, and he was very needy, because his father had just left. He was a sweet, quiet kid. He was always standing near me. He was just so sweet and loved words…He told me he used to read the dictionary.

So assuming his teacher is remembering correctly, and assuming 12th grade reading level is clearly defined, it’s interesting to ask what his IQ might be, given that reading comprehension is an excellent proxy for IQ.

According to the following formula:

IQ = 62.333+4.333(reading level)

An adult with a 12th grade reading level has an IQ of 114 (white norms).

But Jay Z obtained this score in the sixth grade, which presumably means he was probably 11 to 11.9 years old.  Let’s say 11.5.

If an 11.5-year-old performs like a white adult (age 16+) on an intelligence test, they were historically assigned a ratio IQ of 139, because their mental age is 139% as great as their chronological age (16/11.5 = 1.39).

But the young Jay Z reportedly did even better than an average white adult, scoring as high as a white adult with an IQ equivalent of 114, so we multiply his ratio IQ by 1.14 which raises it to about 160.

Ratio IQ of 160 equals deviation IQ of 147

But keep in mind, that for reasons that are not well understood, ratio IQs are normally distributed between IQ 70 to 130, but begin to depart from the Gaussian curve the further you go beyond those limits, which is one reason why you sometimes hear ridiculous claims about people with IQs above 200.

Partly to avoid such hyperbole, IQ tests shifted to the deviation scale, where IQs were forced to fit the Gaussian curve.

According to scholar Vernon Sare, one in 1,170 (white) children have an age ratio of 160+, so fitting Jay Z to a normal curve with a mean of 100 and a standard deviation of 15, his IQ would be 147.

Smartest black “thug” in America?

To put an IQ of 147 in perspective, I note that the delinquent black male underclass (which Jay Z was part of as a young man) seems to have a mean IQ 75.77 with a narrow SD of 8.24 (white norms).  Assuming about several million U.S. black men belong to this class, and assuming a normal distribution, we’d expect the highest IQ among them to score maybe five standard deviations from their mean; or roughly IQ 117.

Of course assuming a Gaussian curve is probably way too simplistic an assumption in this case, and the stats I cite might not be sufficiently representative.  Nonetheless, Jay Z’s IQ of 147 towers over the theoretically expected highest IQ of his demographic.

This may help explain why Jay Z was able to adapt.  Despite being raised in the inner city, surrounded by violence, without even a high school diploma, or access to affirmative action or Ivy League schools; despite not having light skin or being considered good looking, or even musically talented, he was able to turn the situation around to his advantage, by turning his horrible violent life into popular art, and turning that art into a half-billion dollar fortune.

The fact that Jay Z is arguably both the richest black “thug” in America, and also the “smartest”, once again shows the incredible correlation between IQ and income.

But unlike other high IQ people who got rich after attending Ivy League schools and entering educated occupations, Jay Z was a high school dropout who made his money in a low IQ subculture.  This shows that the correlation between IQ and success is not just a artifact of academic credentials and access to the dominant culture, and IQ is not just a measure of “book smarts”, but rather IQ might measure a real evolved brain capacity to adaptively problem solve across a wide range of environments, even those quite alien to the test constructers themselves.