Saturday, February 02, 2013

IQ and homicide

The inverse correlation between mean white IQ (as estimated by NAEP scores) and the white homicide offender rate at the state level in the US is a statistically significant .67 (p = 0).

A few technical notes: Florida is excluded for lack of adequate FBI uniform crime reporting data. "White" includes Hispanics who racially identify as white. To compute the total white NAEP scores for each state, I took NAEP results for 8th graders from 2005 and then weighted the non-Hispanic white and Hispanic scores according to how much of the total white test-taking population each comprised. For the states in which the Hispanic population is too small to be reliably reported, I used the average Hispanic score from the states where the Hispanic populations are large enough for mean scores to be reported.

Intelligence doesn't just improve quality of life measures in a cerebral way, it also does the physical body good.

7 comments:

Lurking Apple said...

p = 0?

How does that work?

Audacious Epigone said...

I always round two decimal places out. I guess I could write (p = .00) for consistency.

Rob King said...

p cannot be 0. It could =.05, for example, it could be <.0001, for example but it cannot equal 0. This error usually comes about from cutting and pasting from SPSS (or similar).

Audacious Epigone said...

Rob,

Right, I just round it. In the future I'll use (p = <.01) when the result is less than .005.

Anonymous said...

"Intelligence doesn't just improve quality of life measures in a cerebral way, it also does the physical body good."

Correlation or causation?

If the genetic load idea is correct then peoples who selected for high IQ wouldn't necessarily be more healthy but populations who selected for low genetic load might be both more healthy and more intelligent.

Audacious Epigone said...

Anon,

Relevant point, though I was just referring to not being shot or stabbed.

Anonymous said...

"I was just referring to not being shot or stabbed"

Yeah it was a separate thought that struck me as i read your post.