Not that I think the study is worth a crap to begin with because I haven't seen the study. I've only seen a report on it. But I think it's nevertheless important to include this statement:
In an email to The Huffington Post, Eidelman clarified that this conclusion does not imply that conservatives are intellectually lazy. “Our research shows that low-effort thought promotes political conservatism, not that political conservatives use low-effort thinking,” he said.
From The Huffington Post:
Of course, I think psychology is a soft science to begin with. People start off wanting to show something and find a way to show it. It's not like saying, "Adding vitamin B to soil will cause corn to grow faster." In a sitaution like that you can do experiments to see if that's really true. And you can measure growth rate in very objetive terms.
A study like the one this thread is about means the investigator chooses certain questions and responses and characterizes them as "conservative" or not. And the investigator can pick questions that are most likely to give them the results they want.