In a previous post, I argued that the public doesn’t particularly need a sophisticated scientific understanding of climate change (or evolution, or stem cells) in order to make the right basic policy decisions. A rudimentary understanding, deliverable and understandable by a layman, is perfectly sufficient. We’re warming the climate? It’s gonna hurt us? Let’s stop. Bada-bing, bada-boom.

Given this, and given the fact that such rudimentary explanations of the science are ubiquitous, the obvious question is: why does the public persist in believe in goofy things, and supporting goofy policy?

The assumption of many scientists is: the public needs more facts! More science! More education!

This is the assumption Mooney and Nisbet were trying to dislodge. More facts &#8800 more understanding. People begin with a worldview, a set of assumptions and values and predilections, and tend to work backward from there, gathering facts that are convenient. Inconvenient facts just slide right off.

So if scientists want to persuade, instead of just lecture, they must take those worldviews and values into account.

Now, a scientist might say, "well, that’s a job for someone with a talent for, or training in, rhetoric — not for a scientist." And that’s a valid point. Indeed, much of the training scientists go through tends to maladapt them to the task of effective public communication.

The reason I think scientists should stay involved in the public realm is that they have a great deal of authority in our culture. When a scientist says something, it’s taken seriously, even if it’s not a scientific fact or result. That give scientists a great deal of social power. And as all Spider-man fans know, with great power must come great responsibility.

So how could scientists improve public communication? The first step is acknowledging the obvious: the reason they ventured into the public sphere in the first place has to do with their values, and their desired ends. It is not, and never has been, purely to impart knowledge.

Consider RealClimate. Did the scientists involved in the site really start it purely to raise the level of public knowledge about climate change? I think not. They wanted to raise the public level of knowledge about climate change because they thought by doing so they would make it more likely that society would address the problem.

In other words: they want society to act to fight climate change. They want action. That’s their ultimate goal. Why pretend otherwise? It’s not like that’s some nefarious ulterior motive. It doesn’t corrupt the science they do. In the practice of science, they can’t let their values or desired policies affect their work. But there’s nothing that says they can’t openly act on their values in the public realm.

They see a huge problem that’s going to cause widespread suffering; they want us to do something about it. That makes them decent human beings, not impure scientists.

As for the rules of effective persuasion, well, they’re the same for scientists as anyone else. The point to scientists is just: if you go out in public, study those rules. Accept that you are attempting to persuade, not just to impart dry facts, and take responsibility for it. If you don’t want to be in the persuasion business, don’t speak out publicly. Just don’t have any illusions.