The replicability crisis in psychology

In recent years, since the early 2010s, the scientific community has drawn attention to the existence of a replicability crisis in science, especially in psychology and medicine: the results of many investigations are impossible to replicate or, simply, there are no attempts to do so.

However, the problems related to the confirmation of hypotheses are not the only ones that are included in the replication crisis, rather it has a broader character. In this sense, it is worth noting the relevance of falsification of results, particularly in the field of social psychology, and other highly significant methodological factors.

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The replicability crisis in science

One of the foundations of the scientific method is the replication of results.. Although many people have a marked tendency to take the conclusions of a single study as credible and definitive, it is It is true that a hypothesis only becomes truly solid when it is confirmed by several valid studies from different research teams. investigation.

In the same sense, negative results, that is, the refutation of hypotheses, are just as important as their verification. However, the proportion of studies that refute claims seems to have decreased in science in general; consequently there is a clear primacy of publications that corroborate experimental hypotheses.

Many of the publications that have been carried out around the replication crisis highlight the magnitude that it has taken on in psychology. However, it is necessary to explain that this crisis affects science as a whole and that also has a particular intensity in the case of medicine. This is due to a number of interrelated factors.

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The main causes of this phenomenon

A meta-analysis by Daniele Fanelli (2009) concludes that fraud in publications is more common in medical and pharmaceutical research than in the other fields. The author suggests that this may be due to the great magnitude of the financial incentives for publications or to a greater degree of awareness in these areas.

There are, however, various factors that influence the replicability crisis beyond the explicit falsification of data. One of the most significant is the selectivity of the publications: in general the positive results and flashy have a greater potential to appear in magazines and to bring recognition and money to researchers.

This is why the "drawer effect" frequently occurs, whereby studies that do not support the expected hypotheses are discarded while those that do are selected by the authors and published more commonly. In addition, the non-replication of positive studies decreases the risk that the hypotheses are refuted.

Other common practices that have similar goals are selecting a large number of variables and then focusing only on those that correlate, changing the size of samples (for example, enroll subjects until results are positive) or perform multiple statistical analyzes and report only those that support the hypothesis.

Why is it so serious in psychology?

The replication crisis in psychology is considered to date back to the early 2010s. During this time Numerous fraud cases arose involving relevant perpetrators; for example, the social psychologist Diederik Stapel falsified the results of several publications

A meta-analysis by Makel, Plucker, and Hegarty (2012) found that only about 1% of psychology studies published since the turn of the 20th century are replications of previous studies. This is a very low figure as it strongly suggests that many of the conclusions drawn from isolated studies cannot be taken as definitive.

The number of successful independent replications is also low., standing at around 65%; instead, more than 90% of those carried out by the original research team corroborate the hypotheses. On the other hand, jobs with negative results are also especially rare in psychology; the same can be said of psychiatry.

Solutions to the research crisis

The replicability crisis in psychology and in science in general not only compromises the results of a large number of studies, but can also lead to the legitimation of hypotheses that have not been confirmed with the necessary rigor. This could lead to the widespread use of incorrect hypotheses, altering the development of the sciences.

At present there are many economic interests (and others also related to prestige) that favor the replication crisis to continue. While the criteria followed regarding the publication of studies and the dissemination of their results in large media continue to have this monetarist character, the situation will hardly be able to change.

Most of the proposals that have been made to help solve this crisis are associated with the rigor in the methodology in all its phases, as well as with the participation of other members of the scientific community; In this way, it would be a question of strengthening the process of "peer-review" and of trying to encourage replication efforts.

concluding

It must be taken into account that in the field of psychology we work with many variables, on the one hand, and it is difficult to establish a context in which the starting point is similar to that of another study, for the other. This makes it very easy for elements not taken into account in the research to "contaminate" the results.

On the other hand, the limitations of the ways in which it is decided whether there are real phenomena or only statistical phenomena mean that sometimes false positives: the mere fact that the p-value is significant is not necessarily enough to indicate that it reflects a psychological phenomenon real.

Bibliographic references:

• Fanelli, D. (2009). How many scientists fabricate and falsify research? A systematic review and meta-analysis of survey data. PLOS ONE 4(5).

• Makel, M. C., Plucker, J. TO. & Hegarty, B. (2012). Replications in psychology research: how often do they really occur? Perspectives on Psychological Science, 7(6): 537-542.

• Nosek, B. A., Spies, J. R. & Motyl, M. (2012). Scientific Utopia: II. Restructuring incentives and practices to promote truth over publishability. Perspectives on Psychological Science, 7(6): 615-631.