Sample Size 43?
Except … the actual data showed that self-described conservatives are more likely to act. That is not in accordance with the theory that liberals are more accepting.
Analyzing the data, Sulloway said liberals were 4.9 times as likely as conservatives to show activity in the brain circuits that deal with conflicts, and 2.2 times as likely to score in the top half of the distribution for accuracy.
Sulloway said the results could explain why President Bush demonstrated a single-minded commitment to the Iraq war and why some people perceived Sen. John F. Kerry, the liberal Massachusetts Democrat who opposed Bush in the 2004 presidential race, as a flip-flopper for changing his mind about the conflict.
Based on the results, he said, liberals could be expected to more readily accept new social, scientific or religious ideas.
Sulloway's claim has been criticized on the grounds that, in the real world, liberals are often resistant to change. (My theory, for whatever it's worth, is that liberals are indeed more willing to change their minds on an individual basis to the opinion of the local crowd, but only if that local crowd consists of people who believe in such “flexibility.” That doesn't mean the crowd changes its mind readily.)
On the other hand, this study is based on a sample of 43 subjects. That's not enough for any firm conclusion.
The Stroop Test
There is, by the way, an established psychological test for reflective flexible thinking known as Stroop test. If that hasn't been used to show liberals are more flexible than conservatives then, considering the leftist bias of many psychologists, then the claim probably isn't so.
On the other hand … a Google search appeared to show that more flexible minds (according to the Stroop test) are also at higher levels of the Kohlberg scale of moral development. Lawrence Kohlberg's research, often cited by liberals, appeared to show that as people develop their moral standards they become more and more like Kohlberg. (There is no truth to the the rumor that he dislocated his shoulder while patting himself on the back.) The Google-search results might mean that a real psychological test showed that genuinely-flexible minds might really be more liberal.
On the gripping hand … the most interesting-sounding of the Google-search results were links to non-open-access journals. So if you wonder why I sounded slightly-deranged on the topic of open vs. closed access …