Results of scientific studies are stated in probabilistic terms. Science is not in the business of making claims of absolute certainty (refer to bead model of truth). When science describes, predicts or explains something, it is understood that the conclusion is tentative. This willingness to admit fallibility is probably one of science’s biggest strengths. In virtually every other area of knowledge acquisition, admitting fallibility is not a virtue, but a severe weakness.
Person-who statistics: situations in which well-established statistical trends are questioned because someone knows a “person who” went against the trend (Stanovich, 2007). For example, “Look at my grandpa, he is ninety years old, has been smoking since he was in thirteen, and is still healthy”, implying smoking is not bad for health. Learning to think probabilistically is an important trait that can increase one's ability to think more accurately. Person-who statistics is a ubiquitous phenomenon.
Research shows people have a difficult time thinking probabilistically. People like things stated in terms of absolute. However, many things cannot be explained in those terms, and in fact when referring to causation in everyday life we are often wrong. Determining what causes something is not as simple as we would like to think.
The conclusions drawn from scientific research are probabilistic- generalizations that are correct most of the time, but not every time. People often weight anecdotal evidence more heavily than probabilistic information. This is an error in thinking, and leads to bad decisions, and often, irrational thinking.
Stanovich, K. (2007). How To Think Straight About Psychology. Boston, MA: Pearson.