Is Democracy Possible? Appendix

To make sense of this post, you must first read Part 1 and Part 2.

Kahan and his colleagues did not discuss differences between the responses of liberals and conservatives to his four contingency problems, in spite of the fact that political ideology interacted with his other variables in a way that was statistically significant.

The asymmetry thesis, most strongly identified with journalist Chris Mooney, states that politically motivated reasoning is greater among conservatives than among liberals. Social psychologist John Jost and his colleagues present evidence that conservatism is more strongly correlated with measures of dogmatism and resistance to change than liberalism.

There is evidence of ideological asymmetry in the Kahan experiment. Here it is:

Table 5

These curves represent the distributions of the responses in each condition. The high point of each distribution is the mean. To help us keep these findings straight, Kahan has drawn the liberals in blue and the conservatives in red. The top two figures are of little interest. They merely show that liberals and conservatives are equally likely to answer the questions about the skin cream incorrectly.

However, the bottom two graphs show ideological polarization. Specifically, the conservatives are more likely than the liberals to answer the question correctly when the correct answer corresponds with their expectations, and they are more likely than the liberals to answer incorrectly when the correct answer conflict with their ideology. This is true of both the low numeracy participants (on the left) and the high numeracy participants (on the right). Stated simply, the two red distributions are farther apart than the two blue ones.

Of course, since this study involves only a single issue, another way of interpreting these data is that conservatives care more about gun control than liberals do.

Table 6

You can also see this ideological asymmetry in the bottom figure of Table 3, repeated above, where, at most levels of numeracy, the two red lines are farther apart than the two blue lines. In a blog post, Kahan acknowledges this evidence of asymmetry, but contends that it less interesting than the fact that both liberals and conservatives show confirmatory bias at high levels of numeracy. He points out that the greatest evidence of asymmetry occurs at low to moderate levels of numeracy (inside the solid circle). At the very highest levels of numeracy (inside the broken circle), the two conservative groups appear to be converging, while the two liberal groups are diverging.

He's right about that. Committed liberals must acknowledge the disappointing performance of the highly numerate liberals. The only reasonable explanation is that bright, highly educated liberals are biased too. But that doesn't change the fact that, in this experiment, conservatives show more evidence of ideological bias than liberals do.

You may also be interested in reading:

Is Democracy Possible?  Part 1

Is Democracy Possible?  Part 2

Climate of Mistrust

The Open and Closed Mind

Motivated Reasoning