You will be familiar with the Daily Mail’s ongoing project to divide all the inanimate objects in the world into the ones that either cause or prevent cancer. It’s hardly worth documenting the individual cases any more: you can appreciate the phenomenon in bulk, through websites like the Daily Mail Oncological Ontology Project and Kill Or Cure, with its alphabetised list: from almonds, apples and artificial light; through horseradish, hot drinks and housework; to wasabi, water, watercress, and more.
But occasionally one story pops up to illustrate a wider issue, and ‘Strict diet two days a week “cuts risk of breast cancer by 40 per cent” ’ is a good example. It goes on: ‘A strict diet for two days a week consisting solely of vegetables, fruit, milk and a mug of Bovril could prevent breast cancer, scientists say.’
Now, if you read the academic paper which this news article is describing, from the International Journal of Obesity: it’s not a study of breast cancer, and it does not find that the risk of cancer is reduced by 40 per cent. The press release wasn’t exactly a masterpiece of clarity either, but in any case, the study doesn’t even measure breast cancer as an outcome, at all.
If I was to leave it there, the journalist would correctly complain: because after all the grand and misleading claims, firstly, briefly, in the body of the piece, it does mention that the outcome is not cancer, but some hormones related to cancer (with no explanation of how tenuous that relationship is). Then, finally, at the very bottom of the piece, comes the reality. Although it’s not spoken in the authoritative third person of the paper itself, it’s there, in a quote, at paragraph number 19:
But Dr Julie Sharp, senior science information manager at Cancer Research UK, said: ‘This study is not about breast cancer, it’s a study showing how different diet patterns affect weight loss and it’s misleading to draw any conclusions about breast cancer from this research.’
The late caveat, torpedoing the central premise of a news piece, is a common strategy in many newspapers. But what use is this information, at the end of a long article, in paragraph number 19?
The way people read newspapers has been studied widely, using eye-tracking technology. It’s through this that we discover, for example, that when presented with a full-length photograph of a man, men are more likely to look at the penis area than women.
Most of this research is more interested in adverts than news, because research in all fields is driven by money (top left of the page is best, apparently): but there is plenty of other useful stuff, much of it by the Poynter Institute.
They did an early study in 1990, with predictable findings: photos attract attention; eyes travel from the dominant photo to the biggest headline, then teasers, and finally text; text is read the least, headlines the most; and so on.
But their most recent project was far bigger: they took a representative sample of 582 people from four cities in the US, and invited them to read a newspaper and a website as they normally would, wearing the eye-tracking equipment, over five days in 2006, for fifteen minutes each. This yielded a dataset of more than 102,000 eye stops.
Here’s what they found: once a story gets longer than eleven paragraphs, on average, your readers will read only half. A tiny minority will make it to paragraph number 19, where, on this occasion, a fraction of the readers of the Daily Mail would have discovered that the central premise of the news story – that a new trial had found a 40 per cent reduction in cancer through intermittent dieting – was false.
Caveats in paragraph 19 are standard practice for stories with outlandish health claims. Like nipple tassels in 1950s burlesque, they’re a way to keep it legal, but titillating; and in many cases, when the late rebuttal comes from an authority figure – calling for calm in patrician tones – it can feel as if it’s only even there to accentuate the excitement. But if your interest is informing a reader, they are plainly misleading.