Tactful or Doubtful? Expectations of Politeness Explain the Severity Bias in the Interpretation of Probability Phrases

Laboratoire Travail et Cognition, Centre National de la Recherche Scientifique, Toulouse, France.
Psychological Science (Impact Factor: 4.43). 10/2006; 17(9):747-51. DOI: 10.1111/j.1467-9280.2006.01776.x
Source: PubMed


When a statement about the occurrence of a medical condition is qualified by an expression of probability, such as the word possible, listeners interpret the probability of the condition as being higher the more severe the condition. This severity bias can have serious consequences for the well-being of patients. We argue that the bias is due to a misconception of the pragmatic function served by the expression of probability. The more severe the condition, the greater the chance that the listener construes the expression as a politeness marker rather than as an uncertainty marker. When this misconception does not occur, neither should the severity bias. An analysis of interpretations of probability expressions using a membership-function approach validates this account. We discuss the consequences of this bias for the communication of risk within and outside the medical domain.

Download full-text


Available from: Gaelle Vallee-Tourangeau, Jun 14, 2014
  • Source
    • "Research on numeracy skills (Lipkus et al., 2001; Peters et al., 2006) showed in particular that roughly 20–30% people , even when highly educated, incorrectly understand probabilities presented in a ratio format such as 1 in X. Conversely, previous research would suggest that the severity of the condition Y might affect the subjective magnitude of a given probability to develop Y. Research conducted on the subjective interpretation of probability phrases like 'it is possible that you will be affected by Y' showed that the subjective probability increased with the severity of Y (Bonnefon and Villejoubert, 2006; Weber and Hilton, 1990). Although not in the medical domain, these results were extended to raw numbers by Patt and Schrag (2003) who investigated individuals' subjective probability assessments in the climate change field, showing that individuals are more likely to use greater likelihood qualifiers to describe a severe meteorological event (such as a hurricane) than to describe a mild meteorological event (such as a snow flurry), and to unambiguous, objective graphical representation of probability by Harris et al. (2009). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Efficient prenatal risk communication hinges upon parents' grasp of statistical information. When forming their subjective representation of a probability, pregnant women may focus on inappropriate factors and ignore the appropriate factors. The present research investigates the subjective probability that pregnant women derive from statements of the form 'There is a 1 in X chance that the baby will have condition Y,' where the number X and the severity of the condition Y were orthogonally manipulated. Study 1 showed that when judging how big is a 1 in X chance that a child will be affected by condition Y, pregnant women (n = 336) were sensitive to the severity of Y, but selectively numb to the objective number X. Study 2 (n = 461) replicated this pattern, but also showed that numerical numbness could be overcome by a simple intervention, namely, a quick comment that 1 in X was 'above average.' Practitioners must be aware that when forming a subjective probability assessment, pregnant women might be inappropriately sensitive to the severity of Y, and inappropriately numb to the number X, and that a simple communicative intervention can help in overcoming this selective number numbness.
    Prenatal Diagnosis 08/2011; 31(8):809-13. DOI:10.1002/pd.2771 · 3.27 Impact Factor
  • Source
    • "In the context of health communication, [11] showed that the subjective likelihood of bad prospects qualified as ''possible'' was inflated precisely when individuals felt that the doctor was deploying facework, and not otherwise. In other terms, individuals who thought that the use of ''possible'' was a facework strategy also "
    [Show abstract] [Hide abstract]
    ABSTRACT: Health care professionals often need to convey good and bad prospects to patients, and these news can be qualified by various uncertainty terms. Based on a sociolinguistic analysis of the way these uncertainty terms are used, we predicted that they would be interpreted differently by patients as a function of whether they qualified good news or bad news. Two studies investigating causal inferences were conducted among a sample of French university students (Study 1, N=50), and among a sample of Italian pregnant women (Study 2, N=532). Participants felt greater confidence in the conclusions they derived when the news were bad, as compared to the conclusions they derived when the news were good. The findings have implications for health care professionals who communicate good and bad prospects to patients, and who need to qualify the certainty of these prospects. Professionals should be aware that when the news are bad, any hedging term such as "possible" can be misunderstood as an attempt to sugar-coat the pill, and that this misinterpretation can lead patient to inferences that are not shared by the professional.
    Patient Education and Counseling 09/2010; 85(2):169-72. DOI:10.1016/j.pec.2010.09.005 · 2.20 Impact Factor
  • Source
    • "The evaluation of identical numerical probabilities is known to be subjectively influenced by how detrimental the outcome is perceived. The effect has been called the severity bias in the psychological literature (see Weber et Hilton 1990, Bonnefon et Villejoubert 2006, Pighin et. al. 2009). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Moral considerations and our normative expectations influence not only our judgments about intentional action or causation but also our judgments about exact probabilities and quantities. Whereas those cases support the competence theory proposed by Knobe in his paper, they remain compatible with a modular conception of the interaction between moral and nonmoral cognitive faculties in each of those domains.
    Behavioral and Brain Sciences 08/2010; 33(4):335-6. DOI:10.1017/S0140525X1000172X · 20.77 Impact Factor
Show more