Why should the average person acknowledge that scientists might know better than they do?
It is possible to make an argument from the common sense idea that scientists know what they're talking about because they've spent much more time looking at the areas of the natural sciences that we're interested in. Normally, if somebody's spent a lot of time in an area, you'd tend to take their opinion as more valuable.
We believe that you can work out whether someone has the right scientific expertise and experience to make some sensible contribution to scientific debates. It doesn't mean they're right. What you have to do is not sort out the people who are right and wrong; what you have to sort is the people who can make sensible contributions from those who can't. Because once you stop doing that, things go horribly wrong.
That seems like it cuts both ways. Are evolutionary biologists like Richard Dawkins fanning the flames in the way that they engage creationists?
Once scientists move outside their scientific experience, they become like a layperson. I'm not a religious person, but if I want to talk religion with someone, it won't be a scientist; it will be with someone who understands theology (who might be either an atheist or a believer). I believe people like Dawkins give atheism a bad name because their arguments are so crude and unsubtle. They step outside their narrow competences when they produce these arguments.
In our book we too criticize creationism's pretensions to be a science, but we don't treat it as a trivial problem. Our critiques of creationism are: (a) that it stops scientific progress in its tracks by answering questions in a way that closes off further research; and (b) that there is no real attempt to meld the approach with the existing methods of science. We know that the creationists say this is not true, but their hypotheses relate to books of obscure origin or to faith rather than to observation.
How do you distinguish the people who can and can't contribute to a specialized field?
The key to the whole thing is whether people have had access to the tacit knowledge of an esoteric area—tacit knowledge is know-how that you can't express in words. The standard example is knowing how to ride a bike. My view as a sociologist is that expertise is located in more or less specialized social groups. If you want to know what counts as secure knowledge in a field like gravitational wave detection, you have to become part of the social group. Being immersed in the discourse of the specialists is the only way to keep up with what is at the cutting edge.
Is this where interactional expertise comes into play?
Interactional expertise is one of the things that broadens the scope of who can contribute. It's a little bit wider than the old "people in the white coats" of the 1950s, but what it's not is everybody. (Within science, lots of people have interactional expertise, because science wouldn't run without it.)
You did experiments to test your theory of expertise. What did you find?
The original version we did was with color-blind people. What we were attempting to demonstrate is something we call the strong interactional hypothesis: If you have deeply immersed yourself in the talk of an esoteric group—but not immersed yourself in any way in the practices of that group—you will be indistinguishable from somebody who has immersed themself [sic] in both the talk and the practice, in a test which just involves talk.