The changing face of psychology

Transcription

1 The changing face of psychology After 50 years of stagnation in research practices, psychology is leading reforms that will benefit all life sciences Psychology is championing important changes to culture and practice, including a greater emphasis on transparency, reliability, and adherence to the scientific method. Photograph: Sebastian Kaulitzki/Alamy In 1959, an American researcher named Ted Sterling reported something disturbing. Of 294 articles published across four major psychology journals, 286 had reported positive results that is, a staggering 97% of published papers were underpinned by statistically significant effects. Where, he wondered, were all the negative results the less exciting or less conclusive findings? Sterling labelled this publication bias a form of malpractice. After all, getting published in science should never depend on getting the right results.

2 You might think that Sterling s discovery would have led the psychologists of 1959 to sit up and take notice. Groups would be assembled to combat the problem, ensuring that the scientific record reflected a balanced sum of the evidence. Journal policies would be changed, incentives realigned. Sadly, that never happened. Thirty-six years later, in 1995, Sterling took another look at the literature and found exactly the same problem negative results were still being censored. Fifteen years after that, Daniele Fanelli from the University of Edinburgh confirmed it yet again. Publication bias had turned out to be the ultimate bad car smell, a prime example of how irrational research practices can linger on and on. Now, finally, the tide is turning. A growing number of psychologists particularly the younger generation are fed up with results that don t replicate, journals that value story-telling over truth, and an academic culture in which researchers treat data as their personal property. Psychologists are realising that major scientific advances will require us to stamp out malpractice, face our own weaknesses, and overcome the ego-driven ideals that maintain the status quo. Here are five key developments to watch in Replication The problem: The best evidence for a genuine discovery is showing that independent scientists can replicate it using the same method. If it replicates repeatedly then we can use it to build better theories. If it doesn't then it belongs in the trash bin of history. This simple logic underpins all science without replication we d still believe in phlogiston and faster-than-light neutrinos. In psychology, attempts to closely reproduce previous methods are rarely attempted. Psychologists tend to see such work as boring, lacking in intellectual prowess, and a waste of limited resources. Some of the most prominent psychology journals even have explicit policies against publishing replications, instead offering readers a diet of fast food: results that are novel, eye catching, and even counter-intuitive. Exciting results are fine provided they replicate. The problem is that nobody bothers to try, which litters the field with results of unknown (likely low) value. How it s changing: The new generation of psychologists understands that independent replication is crucial for real advancement and to earn wider credibility in science. A beautiful example of this drive is the Many Labs project led by Brian Nosek from the University of Virginia. Nosek and a team of 50 colleagues located in 36 labs worldwide sought to replicate 13 key findings in psychology, across a sample of 6,344 participants. Ten of the effects replicated successfully. Journals are also beginning to respect the importance of replication. The prominent outlet Perspectives on Psychological Science recently launched an initiative that specifically publishes direct replications of previous studies. Meanwhile, journals such as BMC Psychology and PLOS ONE officially disown the requirement for researchers to report novel, positive findings.

3 2. Open access The problem: Strictly speaking, most psychology research isn t really published it is printed within journals that expressly deny access to the public (unless you are willing to pay for a personal subscription or spend 30+ on a single article). Some might say this is no different to traditional book publishing, so what's the problem? But remember that the public being denied access to science is the very same public that already funds most psychology research, including the subscription fees for universities. So why, you might ask, is taxpayer-funded research invisible to the taxpayers that funded it? The answer is complicated enough to fill a 140-page government report, but the short version is that the government places the business interests of corporate publishers ahead of the public interest in accessing science. How it s changing: The open access movement is growing in size and influence. Since April 2013, all research funded by UK research councils, including psychology, must now be fully open access freely viewable to the public. Charities such as the Wellcome Trust have similar policies. These moves help alleviate the symptoms of closed access but don t address the root cause, which is market dominance by traditional subscription publishers. Rather than requiring journals to make articles publicly available, the research councils and charities are merely subsidising those publishers, in some cases paying them extra for open access on top of their existing subscription fees. What other business in society is paid twice for a product that it didn t produce in the first place? It remains a mystery who, other than the publishers themselves, would call this bizarre set of circumstances a solution. 3. Open science The problem: Data sharing is crucial for science but rare in psychology. Even though ethical guidelines require authors to share data when requested, such requests are usually ignored or denied, even when coming from other psychologists. Failing to publicly share data makes it harder to do meta-analysis and easier for unscrupulous researchers to get away with fraud. The most serious fraud cases, such as Diederik Stapel, would have been caught years earlier if journals required the raw data to be published alongside research articles. How it s changing: Data sharing isn t yet mandatory, but it is gradually becoming unacceptable for psychologists not to share. Evidence shows that studies which share data tend to be more accurate and less likely to make statistical errors. Public repositories such as Figshare and the Open Science Framework now make the act of sharing easy, and new journals including the Journal of Open Psychology Data have been launched specifically to provide authors with a way of publicising data sharing. Some existing journals are also introducing rewards to encourage data sharing. Since 2014, authors who share data at the journal Psychological Science will earn an Open Data badge, printed at the top of the article. Coordinated data sharing carries all kinds of other benefits too for instance, it allows future researchers to run meta-analysis on huge volumes of existing data, answering questions that simply can t be tackled with smaller datasets.

4 4. Bigger data The problem: We ve known for decades that psychology research is statistically underpowered. What this means is that even when genuine phenomena exist, most experiments don t have sufficiently large samples to detect them. The curse of low power cuts both ways: not only is an underpowered experiment likely to miss finding water in the desert, it s also more likely to lead us to a mirage. How it s changing: Psychologists are beginning to develop innovative ways to acquire larger samples. An exciting approach is Internet testing, which enables easy data collection from thousands of participants. One recent study managed to replicate 10 major effects in psychology using Amazon s Mechanical Turk. Psychologists are also starting to work alongside organisations that already collect large amounts of useful data (and no, I don t mean GCHQ). A great example is collaborative research with online gaming companies. Tom Stafford from the University of Sheffield recently published an extraordinary study of learning patterns in over 850,000 people by working with a game developer. 5. Limiting researcher degrees of freedom The problem: In psychology, discoveries tend to be statistical. This means that to test a particular hypothesis, say, about motor actions, we might measure the difference in reaction times or response accuracy between two experimental conditions. Because the measurements contain noise (or unexplained variability ), we rely on statistical tests to provide us with a level of certainty in the outcome. This is different to other sciences where discoveries are more black and white, like finding a new rock layer or observing a supernova. Whenever experiments rely on inferences from statistics, researchers can exploit degrees of freedom in the analyses to produce desirable outcomes. This might involve trying different ways of removing statistical outliers or the effect of different statistical models, and then only reporting the approach that worked best in producing attractive results. Just as buying all the tickets in a raffle guarantees a win, exploiting researcher degrees of freedom can guarantee a false discovery. The reason we fall into this trap is because of incentives and human nature. As Sterling showed in 1959, psychology journals select which studies to publish not based on the methods but on the results: getting published in the most prominent, career-making journals requires researchers to obtain novel, positive, statistically significant effects. And because statistical significance is an arbitrary threshold (p<.05), researchers have every incentive to tweak their analyses until the results cross the line. These behaviours are common in psychology a recent survey led by Leslie John from Harvard University estimated that at least 60% of psychologists selectively report analyses that work. In many cases such behaviour may even be unconscious. How it s changing: The best cure for researcher degrees of freedom is to pre-register the predictions and planned analyses of experiments before looking at the data. This approach is standard practice in medicine because it helps prevent the desires of the researcher from influencing the outcome. Among the basic life sciences, psychology is now leading the way in advancing pre-registration. The journals Cortex, Attention Perception & Psychophysics, AIMS

5 Neuroscience and Experimental Psychology offer pre-registered articles in which peer review happens before experiments are conducted. Not only does pre-registration put the reins on researcher degrees of freedom, it also prevents journals from selecting which papers to publish based on the results. Journals aren t the only organisations embracing pre-registration. The Open Science Framework invites psychologists to publish their protocols, and the 2013 Declaration of Helsinki now requires public pre-registration of all human research before recruitment of the first subject Guardian News and Media Limited or its affiliated companies. All rights reserved.