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Understanding Why Some People Reject Science

Investigating the underlying emotional roots of science denial.

The development of the scientific method over the last five centuries has led to unprecedented technological growth, vastly improving the quality of life for humans today. Yet, there are many people who adamantly reject some aspects of science, despite enjoying the fruits of scientific progress in their daily lives.

Political conservatives reject the scientific evidence on human-caused climate change, even though the fossil-fuel economy that has made their lives so comfortable is built on centuries of scientific research. Fundamentalist Christians dismiss the abundant evidence for human evolution as incompatible with their faith, even while mainstream Christians have adopted a compromise “divinely driven evolution” that is in accordance with both their religious and their scientific values.

Belief in ideas that have clearly been disproven by science is still widespread around the world, but they’re particularly rampant in the United States. For instance, recent surveys found that 41% of Americans believed in ESP and around a third each in haunted houses, ghosts, and telepathy. In part, this may be due to a lack of scientific literacy, but even well-educated people can willfully reject science when it comes to issues such as vaccines, genetically modified foods, or climate change.

In a recent review article published in the journal Current Directions in Psychological Science, University of Queensland (Australia) psychologist Matthew Hornsey argues that the motivated rejection of science comes not so much from a lack of scientific literacy but rather from deep-rooted emotions and psychological needs. Thus, the direct approach of providing more information or rational arguments won’t sway a science denier, and the only hope for influencing their attitudes is by appealing to the emotions that underlie them.

Hornsey explains the psychology of science rejection by using a tree metaphor. The antiscientific attitudes that the person expresses are like the branches of the tree, as these are what we can readily observe. Education then is like pruning. You can cut off the anti-vax or flat-earth branch with the right arguments, but it will just grow back. That’s because the above-ground branches are nourished and supported by the underground roots, which are deep emotional and psychological needs that the person may not even be fully aware of.

In his tree model for the motivated rejection of science, Hornsey elucidates six “attitude roots”:

Ideologies. People subscribe to certain belief systems that strongly define who they are as a person, and they are motivated to reject any aspect of science that doesn’t align with their ideology. Two examples are pertinent here, namely the rejection of human evolution by fundamentalist Christians, and the rejection of climate change by those holding conservative political views.

The acceptance or rejection of climate science is related to political affiliation and education, but in an interesting way. As liberals become more educated, their confidence in the science of climate change increases. However, it’s the opposite for conservatives, who become more committed to a rejection of climate change as their level of education increases. Thus, climate skepticism isn’t just about a lack of scientific literacy but rather about a conflict with ideology.

Vested interests. Generally speaking, people strongly support scientific progress—after all, smartphones, computers, medicines, and many other technological advances have vastly improved our lives compared to previous generations. But we often balk when a scientific finding implies a cost or inconvenience on our part.

Vested interests also play an important role in climate-science skepticism. Obviously, those involved in the fossil-fuel industry are highly motivated to reject climate change. Likewise, political conservatives—with their desire to maintain the status quo—are resistant to the lifestyle changes required to address global warming.

Conspiracist worldview. The vast majority of people clearly see conspiracy theories as highly implausible. However, a subset of the population holds deep beliefs that the world is ruled by conspiracies, and as a result they’re open to conspiracy theories of all sorts. Thus, a person who believes the moon landing was faked will likely also subscribe to conspiracy theories about 9/11, the murder of JFK, “chemtrails”, and microchips in vaccines.

Due to their conspiracist worldview, all of these conspiracy theories and plenty of others besides simply “make sense” to them, because this is how the world works from their point of view. Of course, they didn’t arrive at their conspiracist worldview through rational means. Rather, conspiracy theories assuage their anxieties and deep sense of helplessness.

Fears and phobias. Going back to Hornsey’s tree metaphor, it’s likely that anxiety is the taproot that anchors the whole tree of attitudes in place. For instance, research suggests that antivax attitudes draw on a deep well of anxiety and disgust regarding hospitals and medical procedures.

In one study, respondents were asked to report how squeamish they felt at the sight of blood, needles, and other medically related items. The higher their level of discomfort with these medical triggers, the greater their likelihood of espousing anti-vaccination attitudes. Thus, antivaxxers may argue that they oppose vaccines because they fear Big Pharma is peddling dangerous substances for profit, but it's more likely that this is a rationalization for an underlying irrational fear of contamination.

Personal identities. People who subscribe to conspiracy theories often perceive themselves as social misfits. As outcasts from “normal society,” they have the opportunity through the motivated rejection of science to create a new persona for themselves, namely as the one who is “in the know,” the one who understands how the world really works. In this way, they can bolster their self-esteem and sense of self-worth.

Social identities. While personal identity defines who you are as an individual, social identity defines who you are in terms of what groups you belong to. Thus, another motivation to reject science is to signal group membership. If you are a fundamentalist Christian in the United States, you need to be unequivocal in your rejection of evolution, as you will be shunned from your group if you don’t. For this same reason, faithful members of the Republican Party need to publicly denounce climate change as a hoax.

The advent of social media has seen the rise of online communities that promote all sorts of science denying positions, from the Flat Earth Society to QAnon. Thus, while expressing belief in conspiracy theories can bolster one’s personal identity, it can also provide a social identity, as a member of an elite group with inside knowledge that others cannot or will not understand.

Given the emotional basis for motivated science rejection, it’s clear that an attempt to educate true believers about the errors in their ways are doomed to fail. Instead, Hornsey argues, we need to be sensitive to psychological motivations for rejecting science and instead frame our communication in ways that work around the emotional roots for their beliefs.


Hornsey, M. J. (2020). Why facts are not enough: Understanding and managing the motivated rejection of science. Current Directions in Psychological Science. DOI: 10.1177/0963721420969364

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