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Humans generally are poor judges of how widespread their own and others’ opinions are.

Climate change: what do you think others think?

Humans generally find it difficult to judge how widespread their own and others’ opinions are, and when it comes to climate change, grossly overestimate the numbers of people who reject its existence. (8:15)

  • 16 November 2012

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Glen Paul: G'day, and welcome to CSIROpod, I'm Glen Paul. In psychology it's well understood that humans are generally poor judges of how widespread their own and other people's opinions are. We find it difficult to judge how many others are thinking along the same lines as ourselves, which leads to the false consensus effect.

A new Paper in nature climate change shows that opinions about climate change are subject to these same false consensus effects, and that people grossly overestimate the numbers of others who reject the existence of climate change in the broader community, and that the higher the false consensus bias, the less likely they are to change their opinions.

Joining me to discuss these findings is lead author Zoe Leviston from CSIRO's Climate Adaptation Flagship. Zoe, what made you decide to investigate the psychology of climate change?

Zoe Leviston: The psychology of climate change is a growing topic. I suppose this area of research has really burgeoned in the last five to ten years, and I think it's because there has been a marked increase in vocal questioning of climate change science, a marked increase in the politicisation of climate change itself, and I suppose Social Psychologists in particular have started to see climate change as an issue in which there are obvious underlying psychological processes that are influencing how people form their opinions about climate change, how they see the science and so forth.

So I suppose that was the initial impetus for us to start investigating how Australians respond to climate change, and what some of those underlying psychological processes might be that are shaping people's attitudes, and opinions, and reactions towards it.

Glen Paul: And how did you measure that; how did you conduct your research, and what did it tell you about people's beliefs on climate change?

Zoe Leviston: Well we started with just a very broad survey I guess. It wasn't trying necessarily to pinpoint this false consensus effect we found, but we were interested in establishing I guess a baseline measure of people's opinions and attitudes. I wouldn't say it was a throw away question, but we thought well wouldn't it be interesting to see how people think about what other people think? We know that there are biases in how people estimate the consensus of popular opinion, let's see if that's happening in regards to climate change opinion as well.

And so we asked them a very simple question about the causes of climate change, whether they thought it was happening at all, and if they did whether they thought it was human induced, or whether they thought it was solely natural. And then we asked them directly after that question, “What would you estimate the percentage of opinion to be in the broader Australian community?” And so they basically had four options to choose from – it's not happening at all; I don't know if it's happening; I think its happening but it's due to natural variability; or I think its happening and humans are largely causing it.

We then asked them to estimate the percentage of Australians we thought would fall into each of those four categories, so they typed in a number after each of those statements, and those four numbers had to add up to 100%. And when we investigated that we found that people grossly overestimated the amount of agreement that people would have with their own opinion on the causes of climate change.

Glen Paul: What causes that, do you think, this false consensus effect, and how is it influenced?

Zoe Leviston: Well I think it's a dynamic process and I think it's caused by two things concurrently – (1) I think it's caused by psychological bias or tendency that's inherent in every individual to overestimate the amount of support or popularity for their own opinion, and I think that the deep rooted causes of that are to do with a need for social support. We like to think that what we think is supported by the people that we know, the people in our community and so forth, and that gives us a bit of confidence that what we're thinking is actually the right thing to think as well. So that's kind of the bottom up process, if you like.

But I think there's another thing happening as well, which is more of a top down process, because there are also all of these cultural and societal influences which we base our consensus estimates on, and unfortunately some of these cues can be quite misleading, particularly if you have a potentially biased media, if you only access a small subsection of that media for instance then you can be grossly mistaken actually about levels of actual community sentiment.

So I think this process is dual, that you have these inherent natural tendencies that make you bolster support for your own viewpoint, but you also have these misleading cues in the environment as well that can actually reinforce those psychological tendencies.

Glen Paul: And is that, do you think, similar to the mass communication theory, the Spiral of Silence, where those who disagree with an opinion keep it to themselves out of fear of being ostracised by the group, or by society, or in some cases might even agree, even though they hold a different belief, just to fit in?

Zoe Leviston: Well that's true as well I think. We see from these figures that the overestimation of people who think that climate change is not happening at all, it's a big overestimation, but it's not, I don't think, at a tipping point yet, and hopefully it never will become like that, but I suppose the real risk is that if these consensus biases escalate and perpetuate you will start to see this spiral of silence, and that's something that we would call absolute pluralistic ignorance, where everybody secretly doesn't share this view that climate change isn't happening at all, but they actually think that the vast majority of the community think that way, and therefore they're much less likely to come out and say, “No, we need to do something about this,” for fear of being ostracised.

Glen Paul: So the false consensus effect, is it more prevalent then in an argument where one side doesn't have the scientific facts to back it up?

Zoe Leviston: I would hesitate to make that extrapolation from our data. I think the false consensus effect we found happens for all viewpoints, but we know from other areas of social research that false consensus effects are more prevalent and likely to be greater when people's viewpoints are somehow unsavoury or unpalatable, so when you do the same kind of research studies on things like racial prejudice, on sexism, and so on, people who have I guess less politically correct opinions about that are much more likely to really, really bolster their consensus estimates than people who have more politically correct opinions.

And so I suppose you could make the speculation that people who deny climate change somehow maybe unconsciously realise that this is not a particularly good opinion to have in current society, and so that there is that unconscious need to bolster the amount of social support that they think they have.

Glen Paul: Hmm. But the study also found that people with this high false consensus bias are less likely to change their opinion, so why is that?

Zoe Leviston: I think it could be due to false consensus effects producing more entrenched viewpoints. If you think that you have a large amount of support for your own view, you're less likely to change it over time, whereas you might have this opinion about climate change that you're quite ambivalent about, you're not sure how many of your friends, and family, and people out there in the community, actually think like you, you're actually open to different arguments, you get to listen to a lot of viewpoints, and so I think we see a greater tendency for these people to shift their opinions over time.

Glen Paul: Yeah, I guess it always is important to look into the facts, and spend less time being a sheep. Thank you very much for discussing your work with us today, Zoe.

Zoe Leviston: No problem. Thanks very much.

Glen Paul: Zoe Leviston. And for more information about the research or to follow us on other social media, just visit