The Inevitable Evolution of Bad Science
Ed Yong, The Atlantic, Sept. 21, 2016
Bacteria, animals, languages, cancers: all of these things can evolve, which we know from the work of legions of scientists. You could argue that science itself also evolves. Researchers vary in their methods and attitudes, in ways that affect their success, and they pass those traits to the students they train. Over time, the very culture of science is sculpted by natural selection--and according to Paul Smaldino and Richard McElreath, it is headed in an unenviable direction.
The problem, as others have noted, is that what is good for individual scientists is not necessarily what is good for science as a whole. A scientist’s career currently depends on publishing as many papers as possible in the most prestigious possible journals. More than any other metric, that’s what gets them prestige, grants, and jobs.
Now, imagine you’re a researcher who wants to game this system. Here’s what you do. Run many small and statistically weak studies. Tweak your methods on the fly to ensure positive results. If you get negative results, sweep them under the rug. Never try to check old results; only pursue new and exciting ones. These are not just flights of fancy. We know that such practices abound. They’re great for getting publications, but they also pollute the scientific record with results that aren’t actually true. As Richard Horton, editor of The Lancet once wrote, “No one is incentivized to be right. Instead, scientists are incentivized to be productive.”
This is not a new idea. In the 1970s, social scientist Donald Campbell wrote that any metric of quality can become corrupted if people start prioritizing the metric itself over the traits it supposedly reflects. “We realized that his argument works even if individuals aren’t trying to maximize their metrics,” says Smaldino.
He and McElreath demonstrated this by creating a mathematical model in which simulated labs compete with each other and evolve--think SimAcademia. The labs choose things to study, run experiments to test their hypotheses, and try to publish their results. They vary in how much effort they expend in testing their ideas, which affects how many results they get, and how reliable those results are. There’s a trade-off: more effort means truer but fewer publications.
In the model, as in real academia, positive results are easier to publish than negative one, and labs that publish more get more prestige, funding, and students. They also pass their practices on. With every generation, one of the oldest labs dies off, while one of the most productive one reproduces, creating an offspring that mimics the research style of the parent. That’s the equivalent of a student from a successful team starting a lab of their own.
Over time, and across many simulations, the virtual labs inexorably slid towards less effort, poorer methods, and almost entirely unreliable results. And here’s the important thing: Unlike the hypothetical researcher I conjured up earlier, none of these simulated scientists are actively trying to cheat. They used no strategy, and they behaved with integrity. And yet, the community naturally slid towards poorer methods. What the model shows is that a world that rewards scientists for publications above all else--a world not unlike this one--naturally selects for weak science.
“The model may even be optimistic,” says Brian Nosek from the Center of Open Science, because it doesn’t account for our unfortunate tendency to justify and defend the status quo. He notes, for example, that studies in the social and biological sciences are, on average, woefully underpowered--they are too small to find reliable results.
Low statistical power is an obvious symptom of weak research. It is easily calculated, and people have been talking about it since the 1960s. And yet, in over 50 years, it hasn’t improved at all. Indeed, “there is still active resistance to efforts to improve statistical power by scientists themselves,” says Nosek. “With desire to get it published dominating desire to get it right, researchers will defend low statistical power despite it having zero redeeming qualities for science.”
Scientists are now grappling with the consequences of that stagnation. In many fields, including neuroscience, genetics, psychology, ecology, and biomedicine, there’s talk of a reproducibility crisis, where weak and poorly designed studies have flooded the world with doubtful findings.
“As long as the incentives are there, then rewards will be there for those who can cheat the system, whether they do so intentionally or not,” says Smaldino. To improve science, the incentives must change.
Ultimately, “changing incentives across the complex science ecosystem is a coordination problem,” says Nosek. “Institutions, funders, editors, societies, and researchers themselves all need to change their expectations a little or else no change will be effective.”
“I don’t want to be overly pessimistic,” says Smaldino. “There are a lot of really high-quality scientists who strive to do high-quality work. There are tons of individuals realize that quality matters. I just hope that sentiment prevails.”
