Saturday, October 16, 2010

The limitations of IQ

Many who read this blog consider cognitive ability to be extremely valuable. It is. But let's not go overboard. In my view, brain horsepower sometimes gets us in trouble. 

Youthfulness illustrates this. IQ peaks among young people and gradually declines over the lifecourse. I've never been a mental powerlifter, but I was stronger 20 years ago. 

Only an ideologue would deny that young people are often foolish. They do and think foolish things. Prudence, wisdom, judgment--all these require more than the ability to reason abstractly. 

Reasonable people would agree that it's a bad idea for 14 year old kids to be having sex. Most people don't arrive at that position through rational argument, but it seems to me wise nevertheless. Problem is, the people who agree with me tend to be dumb and uneducated. 

The General Social Survey asked participants if it's wrong for young teenagers to have sex. I estimated a model of the relationship between the answer to that question and three predictors: age, IQ, and educational level (sample size = 11, 359).     

Here are the results:

OLS regression coefficients (standardized)
Age .20
IQ -.02
Education -.05

All the relationships are statistically significant (although the IQ and education effects are weak). Older, dumber, and less educated people are more likely to think it's wrong. Of course, the discomfort that many intelligent people have with the concept of wrongness is at play here.

I can imagine myself as a teen arguing, "No harm is done if two young people have sex. It's consensual. They're giving each other pleasure--how can that be bad?" I can also see me debating my parents and winning. Their arguments would go something like, "It's just wrong. God says so."  With maybe a "the girl might get pregnant"  thrown in. On rational grounds, I would probably win the debate, but the inarticulate grownups are right. Teen sex is a bad idea--they arrived at the reasonable view through tradition and by sensing it. This ability needs to be understood and valued alongside mental ability. Conservative thought, of course, has always recognized the wisdom found in instinct and tradition.     


  1. Saint Louis9:33 AM

    Well, higher education now basically teaches people to eschew wisdom. It wasn't always so. I'm sure in the 19th century the uneducated working classes were far more likely to be okay with 14-year old sex than the college educated.

  2. Anonymous10:47 AM

    "Well, higher education now basically teaches people to eschew wisdom."

    This is a very wise statement.

  3. Anonymous2:10 PM

    14 is a little young, I agree. However the real point is marriage. Back when a 20-25 year old guy could marry a girl aged 16-20, everyone just recognized it as the normal healthy situation that it was. Now the expectation of waiting till after after college to get married imposes a near impossible burden on anyone with a normal healthy sex drive. So, yeah, "higher education now basically teaches people to eschew wisdom." Ignore the wisdom of getting married a little sooner.

  4. The "well-educated" are far more likely to have uncritically adopted the body of socially-progressive notions that float around universities, grad schools, and the like. In these circles, sexual fluidity, experimentation, and precocity are generally considered good things.

    The "less-educated" are more likely to know from what they see around them that teenagers are often unable to think through the consequences of sexual activity, and that teenage girls, in particular, are often the sexual partners of older men who have no real commitment to them, particularly if a pregnancy occurs.


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