Who do you believe, a Beard or a Suit? In his regular column, Michael Blastland asks if it's facts or identity that decides who's right.

Picture four authority figures, described below. They're clever, they've written weighty books, and they disagree.

Who do you believe?

The casual guy with beard and open-necked shirt The lean, smooth, designer-glasses and all-in-black type The business-like, short-haired, serious suit-and-tie Or maybe a different kind of man-in-jacket, older and rounder, more avuncular

Stupid question. Isn't the first consideration what they say and the strength of their evidence, rather than how they look?

Maybe not. Because we treat people's appearance as a clue to their values. We expect Suit, for example, to be a patriot who thinks people should stand on their own feet. And so he is. Beard dislikes corporate America and believes in more equality. And really, are you surprised by his views? The designer type is a cool individualist. And Uncle Jacket defends tradition.

The types are crude, comical, they generalise horribly and I've adapted them. But they conform roughly to those used by researchers at Yale University and seem to strike a chord. The research is called the cultural cognition project.

Suits like their information from like-minded Suits - Beards like it from like-minded Beards

Note that the four types of the cultural cognition project are all blokes.

Ok, Beard and Suit weren't the full cultural categories used. You can find out how they really did it by looking at the paper on cultural cognition.

What cultural cognition means is that people form perceptions about the facts mostly in line with their existing values and cultural types - of which appearance is one part.

Do the sources of the information share my values? Can I identify with them? Do they reinforce my self-image? OK then, I'll listen. Suits like their information from like-minded Suits - Beards like it from like-minded Beards. At least, that's the argument. What are women supposed to do?

"Basically the reason that people react in a close-minded way to information is that the implications of it threaten their values," Professor Dan Kahan, who is involved in the cultural cognition project, has said.

"If the implication, the outcome, can affirm your values, you think about it in a much more open-minded way."

The cultural cognition project is an attempt to answer what the researchers call one of the most puzzling questions in science communication - why people persistently disagree - sometimes to the point of political conflict - even when the facts ought to be capable of scientific resolution.

The answer, they suggest, is that identity is more important to us than fact.

So if Beard says something we don't like, we'll say that's just typical of Beard who frankly doesn't deserve to be called an expert and anyway really ought to get a shave. In this way, we'll convince ourselves that the scientific consensus is always on our side.

All this is a problem for those scientists who hope that the facts will triumph and that if they give us more information we will converge on a "sensible" view. The cultural cognition project has found that views actually move further apart as people are given more information.

Image caption Maybe shave off the beard if you want to argue nuclear power is the way forward

Why? Because more information gives us a better chance to assess whether the science supports our self-image and values. If it doesn't, we reject it.

It's not just a question of evaluating information according to the cultural types that deliver it. We actually split along the lines of those cultural types with whom we identify - we become Beards or Suits.

Even if we are receiving information in printed form, we still act according to our cultural type.

For example, what do you think about nanotechnology? Not much, perhaps, if you're unfamiliar with it.

As part of the project, a chart was drawn up measuring the percentage of people who thought the benefits outweighed the risks, before and after being given more information.

More information about nanotechnology did not bring people together, it moved them sharply apart - according to their cultural type.

Suits thought it more beneficial and far less risky the more they heard about it, Beards thought it less beneficial and more risky, even though - and this is key - they were given the same information.

I've been trying to make up my mind what I think about all this - beyond finding it fascinating - without reference to the fact that Kahan wears a brown-ish suit and does a lively presentation.

Is cultural cognition really such a big factor, given everything else that goes to shape our judgements? Does it, as some allege, insinuate a more negative stereotype of the suited individualist than of the others?

If there's truth in cultural cognition, then one response might be despair about the point of argument. But there is another - if you hope to persuade a disbelieving Suit that climate change is real, for example, then the most effective strategy - putting aside the merit of the argument - would be to shave off the beard, wear a sharp suit of your own, and say nuclear power is the answer.