Notes on the resistant reader
Smoking kills. A few people had suspected as much before the second world war, but it was not until 1950 that the scientific evidence began to accumulate that smokers were at dramatically higher risk of lung cancer than non-smokers. Other health risks of smoking would be identified over the years that followed.
Pity the poor smoker. Addicted to a popular product that had seemed harmless, he was now being told that his habit was killing him. (It often was a he, although cigarette companies had also marketed cigarettes to women with the feminist slogan, “torches of freedom”.)
What to do? An editorial in the British Medical Journal captured one solution. “It is said that the reader of an American magazine was so disturbed by an article on the subject of smoking and cancer that he decided to give up reading.”
It’s hard to think of a pithier example of what psychologists call the biased assimilation of information. Biased assimilation refers to the various ways in which we avoid unwelcome facts and seek out information that bolsters our own views. The most obvious example — obvious because it is a fairly novel development and because the mechanics of selecting information are so transparent — is the way we follow like-minded people on social media. But people have long sought out news sources that bolster their particular views of the world, as anyone who has ever had a newspaper round and surveyed the contrasting front pages can attest.
There are plenty of more insidious ways in which we absorb some information sources and miss others. Some of them are hidden and algorithmic. Even if you take care to follow commentators or news sources across the political spectrum, social media companies will show you more of what seems to hold your attention. If you are on the centre-right and share a lot of centre-right articles with your friends, soon enough you will stop seeing much stuff from leftwing columnists, no matter how many of them you think you are following.
Less obvious still are our own mental algorithms, which have been subtly skewing our view of the world for far longer than the internet has existed. Two people with contrasting preconceptions about the world can look at the same information but perceive it very differently. Imagine that you happen to encounter a newspaper article discussing what we know about the effects of the death penalty, including a study by researchers Palmer and Crandall. You are told that these scholars found pairs of neighbouring states with different capital punishment laws, and compared the murder rates in each pair. In eight of the 10 pairs, murder rates were higher in the state with capital punishment. This research suggests that the death penalty does not act as a deterrent.
What to think of Palmer and Crandall’s research? Does it seem plausible? If you’re opposed to the death penalty, then it probably does. But if you’re in favour of capital punishment, then you might quickly notice the potential for sloppy errors. Was this research peer reviewed and professionally conducted? Did Palmer and Crandall consider alternative explanations for the pattern they spotted? Should we really buy the idea of paired comparisons between adjacent states? In short, do Palmer and Crandall really know what they’re doing, or are they hacks?
Do not fear that you might offend Palmer and Crandall. They are fictional. They were dreamt up in the late 1970s by three psychologists, Charles Lord, Lee Ross and Mark Lepper. Lord and his colleagues recruited experimental subjects with strong views about the death penalty and showed them summaries of two imaginary studies.
One of these made-up studies demonstrated that the death penalty deterred serious crime. The other, by the fictitious researchers Palmer and Crandall, showed the opposite. As one might expect, the experimental subjects were inclined to dismiss studies that contradicted their firmly held beliefs. This is biased assimilation in action, not at the level of picking which researcher to follow or which newspaper to read, but at the level of picking which information to accept or to reject.
Lord and his collaborators also discovered something more surprising. In some cases, their opinionated experimental participants were shown brief research summaries. In other cases, they were given more detail about research methods, supplemented with graphs and commentary by other fictional academics. The more detail people saw, the easier they found it to reject the unwelcome evidence. Each new detail was an opportunity to dismiss the whole thing.
We are well used to worrying about people consuming a skewed information diet, shorn of context, detail and balance. We imagine that a balanced, detailed news diet would be better. The study by Lord and his colleagues suggests it would not be as helpful as we might hope — not in the face of a committed believer.
That believer is likely to systematically reject contradictory evidence, meaning that as the balanced evidence pours in, the evidence they actually read, accept and remember piles up only on one side. Loading up both sides of the cognitive weighing scale with equal weights is not going to produce balance if the weights keep accumulating on one side and bouncing out of the other.
We shouldn’t overgeneralise from one study, particularly as Lord, Ross and Lepper deliberately recruited experimental participants who were passionately committed to a point of view. For most people, on most issues, a balanced diet of information is likely to be a healthy one.
Yet that underscores the original point: what we believe about the world depends on which ideas we are open-minded enough to entertain. Providing all the detail and balance in the world is useless when you are faced with a reader or viewer who greets all of it with a selective memory and a lopsided scepticism. A curious and open-minded media ecosystem is undoubtedly important, but so too are curious and open-minded citizens.
Written for and first published in the Financial Times on 20 June 2025.
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