Murders in black neighborhoods cause low black IQ

A commenter alerts Steve Sailer, evidently not in jest, that "breakthrough research" has been published that puts Sailer out of business by establishing "a direct causal relationship that can't be explained away by other factors" between murder rates and IQ. "Curiously", Hispanic IQs remain unaffected by black murders in their neighborhoods. I'm certain that the Sailer commenter's confidence is well-placed and the researcher can't possibly have causality reversed here, but if you care to examine his methods and have access to PNAS, here's a link to the the paper.

15 comments:

bertie wooster said...

Be on the lookout for my upcoming paper, which will deal the ugly sort of racism practiced by Sailer a death blow.

In it, I sensationally reveal that doing poorly in school lowers one's IQ, and this accounts for most, if not all, of the observed black-white IQ gap.

Nanonymous said...

In a nutshell, this is what the paper reports:

Children performance on two verbal skills tests is worse after a homicide in the immediate neighborhood. The performance is worse at four-seven days after the homicide than at 14-28 days after it. The effect is seen for Blacks but not Latinos.

I find the results utterly unremarkable. The only interesting finding is Black-Latino difference and, since most victims even in Latino neighborhoods are Blacks, it only tells us something about kids' level of exposure to the streets/murders.

If this is what passes for research in sociology today, then we may as well do away with sociological research altogether - nothing of any importance will be lost.

"Murder rates affect IQ tests scores" is a misleading description of it. "Murders in black neighborhoods cause low black IQ" is even more misleading description.

patusor said...

Don't know about this Sharkey guy, but the "prearranged editor" of the paper, Robert Sampson is an outspoken immigration booster.

Anonymous said...

"Children performance on two verbal skills tests is worse after a homicide in the immediate neighborhood. The performance is worse at four-seven days after the homicide than at 14-28 days after it."

Maybe after a murder only the stupider black children risk their necks to go and have their IQs tested.

Where the IQ tests performed in an area where you'd have to pass a rough part of town to get to it?

Anonymous said...

"Children performance on two verbal skills tests is worse after a homicide in the immediate neighborhood. The performance is worse at four-seven days after the homicide than at 14-28 days after it."

Maybe after a murder only the stupider black children risk their necks to go and have their IQs tested.

Where the IQ tests performed in an area where you'd have to pass a dangerous part of town to get to it?

(That seems likely.)

Anonymous said...

Think of it this way: If you have a relative high IQ and there was just a murder in your neighborhood, wouldn't you rather stay indoors than go out to have your IQ tested?

It's not like you would get paid for taking the IQ test, and there's nothing says you couldn't just get your IQ tested after the violence in your area died down.

In contrast lower IQ people tend to have less aversion to risk, if traffic accident data is any indication, and less awareness of what's going on around them.

Anonymous said...

I didn't read the paper, so I may be glaring over points that explain this away:

Pretty much any ghetto black neighborhood is going to have a high rate of violence and murder. So it isn't the murders causing the low IQ, but rather the geographic collection of low-IQ blacks that leads to more murders.

The case where blacks test with higher IQ in less violent neighborhoods could be easily explained by sampling from higher-class (i.e. to the right of the IQ bell curve) blacks in which murder and violence is less likely.

Anonymous said...

"Pretty much any ghetto black neighborhood is going to have a high rate of violence and murder. So it isn't the murders causing the low IQ, but rather the geographic collection of low-IQ blacks that leads to more murders."

They did break it down by race, so that black children were only compared to other black children.

Anonymous said...

They only compared black children to other black children.

At the same time the sorts of blacks who live in neighborhoods with higher murder rates are probably lower IQ than the sorts of blacks who live in lower crime neighborhoods.

Anonymous said...

From the paper:

"To maximize precision of the estimates, neighborhood fixed effects are used instead of neighborhood by survey wave fixed effects, which are used in the analysis based on the PHDCN. Identification in the neighborhood fixed effects approach is based on variation in exposure to local homicides among children living within the same neighborhood (block group, census tract, or neighborhood cluster), regardless of the survey wave in which the interview was conducted. Allowing for comparisons across survey waves improves the precision of estimates and is less problematic in the Three City Study because the first and second waves of the survey were conducted over a very short time span, ranging only from 1999 to 2001."

Anonymous said...

"Children performance on two verbal skills tests is worse after a homicide in the immediate neighborhood."


This is simply a manifestation of the "Don't be snitchin'" philosophy espoused by ghetto blacks. Maybe they knew something about he murder and figured talking to any authority - including someone administering a formal test - was a violation of said philosophy.

Actually that was meant as a joke, but the more I think about it...

Anonymous said...

Maybe this is more evidence of black's "greater empathy. for other blacks.

Although this example is curiously lacking said "empathy." If anything they show a remarkably low level of empathy and conscientiousness.

http://www.youtube.com/watch?v=WQcYWXO7yU4

Anonymous said...

I suspect that the anonymous commenter at Sailer's was being ironic. Anyway, this comment by Mark Wethman points out how Sharkey exaggerates his results:

The effect doesn't actually account for one half the black-white IQ gap. It accounts for, at most, 12%. The author is spinning the findings.

"When one takes into account the prevalence of homicide in the most violent neighborhoods in cities like Chicago, these results mean that some children spend about one week out of every month functioning at a low level as they navigate the home or school environment," he said in a statement.

In other words, in the most violent of neighborhoods, there's a one in four chance that a black child will be scoring a half standard deviation lower than he otherwise would due to post-traumatic stress. Let's assume that ALL black children live in the most violent neighborhoods for the sake of argument. Take 100 of these kids, who scored an 85 on an IQ test, on average. 25 of those kids were suffering post traumatic stress, and would have scored 92, on average, if not for that stress. So what you really have is a group of 75 kids with a proper average score of 85, plus 25 kids with a proper average score of 92. The average score for the two groups comes out to 86.75. So at most, this only depresses average black IQ by 1.75 points, or 12% of a standard deviation
.

In all likelihood, the black IQ deficiency compared to whites is more than 15 points in the worst neighborhoods, so perhaps the violent atmosphere contributes to that. I skimmed Sharkey's paper, but I don't think he tells what the average IQ is in the neighborhoods studied.

Anonymous said...

They wouldn't have causality reversed if the study found the IQ scores to drop after the murders, then subsequently rise back up.

p.n. said...

I agree with some of the sarcastic comments. The researcher is an idiot to point the causality in one direction. Not only is a group having lower iq going to kill more but is say number people are more likely to live around killers. That said I'm sure there's some small negative eglffect on iq after nearby killings.

The idea of the guys research is odd anyways. He didn't prove anything ground breaking and who cites if their iq drops a tiny amount. We should be a help if a lot more concerned with the chance of them getting killed.

That's something I don't know how to do.