New research finds even a brief exposure to a film that portrays climate change as a hoax impacts people's attitudes and intentions.

The 2007 documentary the Great Global Warming Swindle. (Photo: Tired time/Wikimedia Commons)

Last week, we noted that the term "conspiracy theory" seems to have lost many of its negative connotations. This disconcerting conclusion aligns with a 2014 study that found half of all Americans believe in at least one such theory, and many people who reject them are unwilling to do so categorically.

On one level, the implications of this are obvious and troubling: Such thinking makes serious discussion of societal problems extremely difficult. But according to another newly published study, the problem with being open to conspiracy theories goes deeper than that, and its ramifications are more immediate.

Princeton University psychologist Sander van der Linden reports that even brief exposure to a conspiracy theory regarding climate change was enough to shift people's attitudes away from the scientific consensus. He also found some evidence that such misinformation may impact our behavior in other, negative ways.

Conspiracy theories are both tantalizing and dangerous, in that they not only spread misinformation, but dampen willingness to take action.

"Researchers and policymakers should not underestimate the socio-cognitive potency of conspiracies," he writes in the journal Personality and Individual Differences. "Growing public belief in, and potential exposure to, conspiracy theories can have negative and undesirable social consequences."

His study featured 316 American adults recruited online. Some were randomly chosen to spend two minutes solving a neutral word puzzle; others were selected to view a two-minute clip of either the Great Global Warming Swindle, a popular conspiracy-oriented documentary, or Raise Your Voice About Climate Change, a United Nations-produced film.

Afterwards, participants were asked a series of questions. They estimated what percentage of climate scientists have concluded that human-caused climate change is real; indicated their willingness to sign a "stop global warming" petition; and reported their likelihood of donating to, or doing volunteer work for, any sort of charity over the following six months.

Van der Linden found that, even on a topic that has engendered much public discussion, brief exposure to the concept of a conspiracy shifted people's thinking. Specifically, he reports, those who saw the clip from the conspiracy video "judged the scientific consensus on human-caused climate change significantly lower" than those who did not.

They were also more complacent. Forty-three percent of people who had seen the U.N. video agreed to sign the petition, compared to less than 23 percent of those exposed to the conspiracy theory (and 34 percent of those who saw neither).

What's more, van der Linden found those who saw the conspiracy theory clip were marginally less likely to donate or volunteer for charity work—a finding that suggests exposure to a conspiracy puts at least some people in a less-giving state of mind.

While that's intriguing, the key finding is the reduced belief in the scientific consensus regarding climate change. Understanding that there is no longer any real debate among climate scientists on this subject is "an important 'gateway' cognition that guides other key beliefs about the issue," van der Linden notes, "such as the belief that climate change is happening, human-caused, and a worrisome problem that requires public action."

So conspiracy theories are both tantalizing and dangerous in that they not only spread misinformation, but dampen willingness to take action. Anyone who thinks they're too silly to refute had better think again.

Findings is a daily column by Pacific Standard staff writer Tom Jacobs, who scours the psychological-research journals to discover new insights into human behavior, ranging from the origins of our political beliefs to the cultivation of creativity.