A new study shows that we tend to overstate our negative feelings and symptoms in surveys.
According to researchers at New York University, this bias wears off over time, but the results point to the possibility that measurements of health and well-being, which are vital in making medical assessments and in guiding health-related research, may be misinterpreted.
“Understanding the magnitude of this bias is essential in accurately interpreting survey results that include subjective reports of feelings and symptoms,” said Dr. Patrick Shrout, a professor in New York University’s Department of Psychology and a co-author of the paper, which appears in the journal Proceedings of the National Academy of Sciences.
While researchers have long understood that survey instruments are imperfect measurements of mood and emotions, they do provide insights into people’s preferences, fears, and priorities — information that policy makers, industry leaders, and health-care professionals rely on in their decision-making.
Less clear, however, is the accuracy of capturing our sentiments over time using repeated measurements, which is a common method to gauge changes in symptoms, attitudes, and well-being, the researchers said.
They point to puzzling findings in the psychological literature that reports of anxiety, depression and physical symptoms decline over time, regardless of the circumstances of the people being studied.
To study this decline, the NYU researchers conducted four separate experiments in which the subjects were asked, multiple times, about their anxiety, physical symptoms and energy level.
In three of the four studies, the subjects were facing stressful events and the expectation was that anxiety and physical complaints, such as headaches and sleep disturbance, would be more common as the event drew near.
One of these studies focused on recent law school graduates preparing for the bar examination, while two others centered on college students who were preparing for difficult pre-med science examinations.
The fourth study was a bi-monthly survey of college students over the course of an academic year.
All four studies were designed so that groups of subjects gave their first reports at different times relative to the stressful event or academic year, the researchers explained.
In all the studies, subjects reported more anxiety and symptoms the first time they completed the survey compared to their own later reports, according to the researchers.
This initial elevation was limited to the first survey day, and it was inconsistent with the course of anxiety and symptoms normally associated with a difficult event, the researchers noted.
Although previous researchers assumed the pattern of decline was due to response bias of later reports, the NYU researchers concluded that the pattern of decline over time was likely due to an overstatement of distress and symptoms the first time, rather than an understatement in later times.
This is the only explanation that accounted for the fact that anxiety was more elevated four weeks before the exam than three weeks before, they note.
Moreover, the law school graduates who were asked to report current anxiety and symptoms for the first time one week after the bar exam had elevation similar to others who had not yet taken the exam, the study found.
Source: New York University