Do you believe that “humans and other living things have evolved over time”?

The other day on the sister blog we discussed a recent Pew Research survey that seemed to show that Republicans are becoming more partisan about evolution (or, as Paul Krugman put it, “So what happened after 2009 that might be driving Republican views? . . . Republicans are being driven to identify in all ways with their tribe — and the tribal belief system is dominated by anti-science fundamentalists”).

We presented some discussion and evidence from Dan Kahan suggesting that the evidence for such a change was not so clear at all. Kahan drew his conclusions from a more detailed analysis of the much-discussed Pew data, along with a comparison to a recent Gallup poll.

Also following up on this is sociologist David Wealiem, who pulls some more data into the discussion:

Although the Pew report mentions only the 2009 survey, the question has been asked a number of times since 2005. Here are the results—the numbers represent the percent saying “evolved” minus the percent saying “existed in their present form.”

The 2009 survey is an outlier—everyone was more likely to express support for evolution than they were in the surrounding years. I [Weakliem] am not sure why the results from this survey should be so different from the others, but I noticed that it focused on science, while the others had a mix of topics. So perhaps people felt more inclined to go along with the scientific consensus after answering a lot of questions on science and technology. Another possibility is that people who didn’t have much knowledge of science or faith in science were less likely to agree to participate in a survey on science. In any case, any comparison involving the 2009 results should be taken with a grain of salt.

If you omit the 2009 survey, partisan differences have become a bit wider over the whole period, not because Republicans have become less likely to believe in evolution, but because Democrats and independents have become substantially more likely to believe in it.

But, as Kahan notes, only 36% of surveyed Democrats believed “that humans and other living things have evolved over time due to natural processes”—with another 22% believing in evolution that was guided by a “supreme being.” (My own take on the supreme-being-guidance thing is summarized by item 1 on this list.)

Punked by Pew?

Regarding Weakliem’s post, Kahan writes:

This is true. I pointed out that for all we know 2009 evoluton belief was “high,” in which case prior level of belief (in creatonism) is rebounding etc.

That’s why it’s useful to look, too,, at Gallup, which has been asking same q. for longer time. So has NSF in its science indicators.

No one doubts there is partisan divide, but the idea that it could change a lot in 4 yrs, while certainly *possible,* would be pretty amazing. There’d be more evidence.

But in any event, now that we have all the data, we can see plainly that the only thing that happened even in Pew data was a reallocation of small # of Repubs between “divine guided evolution” (somethin akin to “intelligent design”) & “creationism.” There was no meaningful shift in proportion of Repubs rejecting *real* evolution (natural selection kind).

In fairness, Pew baited the misunderstanding trap by failing to release the the partisan breakdown for *entire* question in its initial “report”/”press release.” Not only concealed that Repubs hadn’t shifted on natural-selection evolution, but that of course the vast majority of Dems don’t accept “natural selection” version either — making “monkeys,” as it were, of the commentators who cited this poll to heap ridicule on Repubs for being “the party that rejects Darwin.”

Basically, the commenators were “punked” by Pew. Very very very unlike Pew, which is the only “public opinion survey” operation that does real opinion studies rather than “issue du jour.” I really love Pew precisely because it isn’t in the ‘opinion polling’ business but in the ‘public opinion analysis’ business. It employs super smart researchers who understand what survey items do & don’t measure & who use that understanding to enlarge knowledge of lots of complicated things, particularly relating to public understanding of science.

P.S. I would label the lines in Weakliem’s graph directly rather than with a legend, also I’d use the conventional red/blue/purple colors rather than black/red/green, and I’d label the y-axis more descriptively. But, hey, I didn’t make the graph, and it’s waaaay better than a table. I make these sort of graphing comments not to discourage or intimidate the Weakliems of the world but rather as suggestions so that the future graphs they make can be even more useful.

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