סמינר בשיווק

Misunderstanding medical probabilities, mis-evaluating how I feel

Abstract:

This talk will explore the difficulties people encounter when dealing with the probabilities of medical events.  

The way probabilities are represented can hugely impact comprehension, because people rely heavily on existing representations.

Examples come from publications on prental screening and from genetic testing for the BRCA 1 and BRCA 2 gene mutations, associated with breast cancer.

Finally, I will discuss a recent Psychological Science on te representation of symptoms, showing that these effects also occur with regards to how people assess their own sy,ptoms. 

People are quick to perceive meaningful patterns in the co-occurrence of events. We report two studies exploring the effects

of streaks in symptom checklists on perceived personal disease risk. In the context of these studies, a streak is a sequence

of consecutive items on a list that share the characteristic of being either general or specific. We identify a psychological

mechanism underlying the effect of streaks in a list of symptoms and show that the effect of streaks on perceived risk varies

with the length of the symptom list. Our findings reveal a tendency to infer meaning from streaks in medical and health

decision making. Participants perceived a higher personal risk of having an illness when presented with a checklist in which

common symptoms were grouped together than when presented with a checklist in which these same symptoms were

separated by rare symptoms. This research demonstrates that something as arbitrary as the order in which symptoms are

presented in a checklist can affect perceived risk of disease.