Once you grant that personality has an important effect on ideology, it's only natural to wonder why. Gerber et al propose what they describe as "two tentative and equally plausible possibilities here, one focused on other regarding judgments and the other focusing on self-interested behavior."
Possibility #1: Some personalities are less self-interested than others. Their example:
One of the key components of Agreeableness is compassion, as opposed to competitiveness. Individuals who are particularly Agreeable may be more inclined to support policies that benefit others, while less agreeable individuals are unwilling to support interventions that do not improve their material self interest.
Possibility #2: Some personalities have different interests than others. Their example:
[W]e might expect people who are low on Emotional Stability to be particularly worried about the possibility that they will lose their health insurance and thus may be more inclined to support a government-sponsored program.
Here's my question: What's wrong with...
Possibility #3: Some personalities see the world more clearly than others.
People high in Agreeableness are emotional and refuse to face the reality of trade-offs. So when someone suggests that the minimum wage might actually hurt the poor by causing unemployment, they just get hysterical. People low in Agreeableness, in contrast, are logical and eager to identify trade-offs. So when you ask them about the disemployment effect of the minimum wage, they calmly consider the argument, and realize that it makes sense.
Now you might think that I'm unfairly maligning the Agreeable as a pack of mushheads. But whose maligning whom? On Jungian personality tests like Myers-Briggs , they don't call it "Agreeableness." They call it "Thinking vs. Feeling." As a person at the 99th percentile of the Thinking distribution, I see the "Agreeableness" label as a conspiracy of the Feeling to condemn me for my truth-seeking disposition. Seriously.
One of the main dimensions on the
Myers-Briggs personality test is Thinking versus Feeling.The breakdown for men is about 60% Thinking,
40% Feeling; the breakdown for women is about 30% Thinking, 70% Feeling. (Briggs
Myers and Myers 1993)Similarly, in the
Five Factor Model of personality, women are about half a standard deviation
more Agreeable than men. (Costa et al 2001; Costa and McCrae 1992: 75)This indicates, in part, that women are more
"moved by others' needs and emphasize the human side of social policies,"
whereas men are more likely to "consider themselves realists who make hard
decisions based on cold logic." (Piedmont 1998: 90) So when
economists argue - as they often do - that good intentions have bad unintended consequences,
and vice versa, we should expect it to alienate the Agreeable/Feeling, and
pique the curiosity of the Disagreeable/Thinking.
Admittedly, I can't prove that my Possibility #3 is right. But doesn't it deserve as much consideration as Gerber et al's "two tentative and equally plausible possibilities"? Whoever said that all personalities have equally accurate beliefs?