An intriguing paper that created headlines three months ago has been withdrawn, following criticisms of its methodology. The good news is that not only is science functioning as it should, but that people with depression at least may not be deprived of the beauties of color.
In August Rochester University's Christopher Thorstenson published a paper in Psychological Science titled Sadness Impairs Color Perception. Thorstenson and two co-authors reported that when a group of people were shown sad film clips, their capacity to distinguish blue from yellow in a subsequent test was reduced, but they did not experience the same trouble with green and red. Moreover, control groups shown either funny or neutral clips were unaffected.
IFLScience was hardly alone in finding this research worth reporting. Numerous other popular science and general news sites did too, encouraged by the traditional association of the color blue and sadness. While the research lacks obvious short term applications, attribution to dopamine's role in blue perception suggested new angles for neurochemistry research.
The authors acknowledge that they failed to perform a test for statistical significance between the responses on the blue-yellow and red-green axis. Without this, they said: “We should not have concluded that our pattern of findings ruled out a motivational explanation.” In other words, the results might be a function of participants who watched the sad clip not trying their best, because life just didn't seem that fun at the time.
Furthermore some of the participants gave the same answers to every blue-yellow test. Whether they were trying or not, these results should have been removed from the sample. Taking out the data from this group didn't change the trial's results, but did leave a suspiciously small sample size.
Nothing in the problems Thorstenson and his co-authors acknowledge indicates that their original claims were wrong, but more research is needed before they can be stated with any confidence.
“Given these two problems, we are retracting this article from the journal,” the authors state in the retraction. “We will conduct a revised Experiment 2 that more directly tests the motivational interpretation and improves the assessment of [blue-yellow] accuracy... We remain confident in the proposition that sadness impairs color perception, but would like to acquire clearer evidence before making this conclusion in a journal the caliber of Psychological Science.”
The retraction is an example of how science should work. In an ideal world problems such as this would be identified through pre-publication peer review, but that is not always going to happen. Rather than faithfully holding to their results, the authors have responsibly acknowledged the problems and are doing further research.
However, in the light of a review finding that most psychology studies can't be reproduced, the latest withdrawal may add to questions as to whether psychology journals are less rigorous in their peer reviews than other fields of science.