Thorsten Pachur

Who they are

He is a psychologist who works on judgement and decision making. The Technical University of Munich Institute for Advanced Study lists a Wednesday Coffee Talk by him, titled "The perception of dramatic risks: Biased media but unbiased minds". The listing carries the title but not an abstract, so this page does not describe the talk's content. The vault holds no other biography, and no further post or career history is claimed.

His co-author Ralph Hertwig has his own entry on this site, as the decision researcher whom Kahneman names as a critic of parts of the heuristics-and-biases programme and whose work this vault links to the gap between decisions from description and decisions from experience.

Key papers

Pachur, T., Hertwig, R., & Steinmann, F. (2012). How do people judge risks: Availability heuristic, affect heuristic, or both? Journal of Experimental Psychology: Applied, 18(3), 314-330.

The study compared the availability heuristic and the affect heuristic as explanations of how laypeople judge risks. In two student-sample studies the authors measured risk perception in three ways: frequency judgements, the value of a statistical life, and perceived risk. They used cancer and a set of heterogeneous causes of death. Availability from recall, which draws on people's direct experience of risks within their social networks, best matched participants' responses. Affective information mattered more for the value of a statistical life and for perceived risk than for frequency judgements. Media exposure to risks played a minor role. The results also suggested that both heuristics may operate together, either sequentially or as a combined composite. The authors discuss implications for improving risk calibration and education campaigns.

Key ideas

The study separates two things that popular accounts run together. One is the claim that people overestimate dramatic risks because the news makes examples available. The other is the claim that availability, wherever it comes from, shapes risk judgement. The 2012 results support the second more than the first. What came to mind was largely what people had encountered through their own networks, and measured media exposure added little.

The feelings result is a second correction. Feelings about a hazard counted for more in judgements of how risky it is and what a life is worth than in judgements of how often it kills. A person's answer depends on the question, which is why a single bias label rarely fits.

For anyone planning communication, the study moves the target. If risk judgements track the experiences of friends, family and colleagues, a broadcast reaches the person at reduced strength unless it resembles something already close to them. That is an inference from the findings and not a result the study reports.

The finding rests on two student samples and on the measures the authors chose. It does not tell us how adults behave when they buy something, and it does not rule out a larger role for media in other populations or other kinds of risk.

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