From EconLog by Bryan Caplan.

When lies sound better than truth, people tend to lie.  That's Social Desirability Bias for you.  Take the truth, "Half the population is below the 50th percentile of intelligence."  It's unequivocally true - and sounds awful.  Nice people don't call others stupid - even privately.

The 2000 American National Election Study elegantly confirms this claim.  One of the interviewers' tasks was to rate respondents' "apparent intelligence."  Possible answers (reverse coded by me for clarity):

0= Very Low
1= Fairly Low
2= Average
3= Fairly High
4= Very High

Objectively measured intelligence famously fits a bell curve.  Subjectively assessed intelligence does not.  At all.  Check out the ANES distribution.



The ANES is supposed to be a representative national sample.  Yet according to interviewers, only 6.1% of respondents are "below average"!  The median respondent is "fairly high."  Over 20% are "very high."  Social Desirability Bias - interviewers' reluctance to impugn anyone's intelligence - practically has to be the explanation.

You could just call this as an amusing curiosity and move on.  But wait.  Stare at the ANES results for a minute.  Savor the data.  Question: Are you starting to see the true face of widespread hostility to intelligence research?  I sure think I do.

Suppose intelligence research were impeccable.  How would psychologically normal humans react?  Probably just as they do in the ANES: With denial.  How can stupidity be a major cause of personal failure and social ills?  Only if the world is full of stupid people.  What kind of a person believes the world is full of stupid people?  "A realist"?  No!  A jerk.  A big meanie.

My point is not that intelligence research is impeccable.  My point, rather, is that hostility to intelligence research is all out of proportion to its flaws - and Social Desirability Bias is the best explanation.  Intelligence research tells the world what it doesn't want to hear.  It says what people aren't supposed to say.  On reflection, the amazing thing isn't that intelligence research has failed to vanquish its angry critics.  The amazing thing is that the angry critics have failed to vanquish intelligence research.  Everything we've learned about human intelligence is a triumph of mankind's rationality over mankind's Social Desirability Bias.