Focus to an attribute with verbal or numerical quantifiers affects the attribute framing effect

People prefer to predict middle, most likely quantitative outcomes (not extreme ones), but they still over-estimate their likelihood

Past work showed a tendency to associate verbal probabilities (e.g., possible, unlikely) with extreme quantitative outcomes, and to over-estimate the outcomes' probability of occurrence. In the first four experiments (Experiment 1, Experiments 2a-c), we tested whether this "extremity effect" reflects a general preference for extreme (vs central or less extreme) values of a distribution. Participants made predictions based on a frequency distribution in two scenarios. We did not find a preference for extreme outcomes. Instead, most of the participants made a prediction about the middle, most frequent outcome of the distribution (i.e., the modal outcome), but still over-estimated the outcomes' probabilities. In Experiment 3, we tested whether the over-estimation could be better explained by an "at least"/"at most" reading of the predictions. We found that only a minority of participants interpreted predictions as the lower/upper bounds of an open interval and that these interpretations were not associated with heightened probability estimates. In the final three experiments (Experiments 4a-c), we tested whether participants perceived extreme outcome predictions as more correct, useful and interesting than modal outcome predictions. We found that extreme and modal predictions were considered equally correct, but modal predictions were judged most useful, whereas extreme predictions were judged to be more interesting. Overall, our results indicate that the preference for extreme outcomes is limited to specific verbal probability expressions, whereas the over-estimation of the probability of quantitative outcomes may be more general than anticipated and applies to non-extreme values as well.

How Should Doctors Frame the Risk of a Vaccine's Adverse Side Effects? It Depends on How Trustworthy They Are

BACKGROUND

How health workers frame their communication about vaccines' probability of adverse side effects could play an important role in people's intentions to be vaccinated (e.g., positive frame: side effects are unlikely v. negative frame: there is a chance of side effects). Based on the pragmatic account of framing as implicit advice, we expected that participants would report greater vaccination intentions when a trustworthy physician framed the risks positively (v. negatively), but we expected this effect would be reduced or reversed when the physician was untrustworthy.

DESIGN

In 4 online experiments (n = 191, snowball sampling and n = 453, 451, and 464 UK residents via Prolific; Mage≈ 34 y, 70% women, 84% White British), we manipulated the trustworthiness of a physician and how they framed the risk of adverse side effects in a scenario (i.e., a chance v. unlikely adverse side effects). Participants reported their vaccination intention, their level of distrust in health care systems, and COVID-19 conspiracy beliefs.

RESULTS

Physicians who were trustworthy (v. untrustworthy) consistently led to an increase in vaccination intention, but the way they described adverse side effects mattered too. A positive framing of the risks given by a trustworthy physician consistently led to increased vaccination intention relative to a negative framing, but framing had no effect or the opposite effect when given by an untrustworthy physician. The exception to this trend occurred in unvaccinated individuals in experiment 3, following serious concerns about one of the COVID vaccines. In that study, unvaccinated participants responded more favorably to the negative framing of the trustworthy physician.

CONCLUSIONS

Trusted sources should use positive framing to foster vaccination acceptance. However, in a situation of heightened fears, a negative framing-attracting more attention to the risks-might be more effective.

HIGHLIGHTS

How health workers frame their communication about a vaccine's probability of adverse side effects plays an important role in people's intentions to be vaccinated.In 4 experiments, we manipulated the trustworthiness of a physician and how the physician framed the risk of adverse side effects of a COVID vaccine.Positive framing given by a trustworthy physician promoted vaccination intention but had null effect or did backfire when given by an untrustworthy physician.The effect occurred over and above participants' attitude toward the health care system, risk perceptions, and beliefs in COVID misinformation.

Cultural Variability in the Attribute Framing Effect

An intriguing phenomenon that arises from decision making is that the decision maker’s choice is often influenced by whether the option is presented in a positive or negative frame, even though the options are, de facto, identical to one another. Yet, the impact of such differential framing of equivalent information, referred to as the attribute framing effect, may not be the same for every culture; rather, some cultures may be more readily influenced by the differentially valenced frames than others (i.e., showing a greater difference in evaluation in a positive vs. negative frame). The present study investigates to what extent and why cultures may differ in their sensitivity to the attribute framing effect. Participants were recruited from South Korea and the United States, cultures characterized by their focus on prevention and promotion, respectively, to test for the cultural variability in the attribute framing effect. The results revealed that Korean participants were markedly more influenced by the valence of the frame than North American participants. Regulatory focus explained why Koreas showed a greater sensitivity toward the attribute framing effect than North Americans. Specifically, a greater prevention (vs. promotion) orientation of Korean participants led them to show a greater evaluation gap in the positive and negative frames. Implications for cultural significance on the attribute framing effect are discussed.

Facilitating sender-receiver agreement in communicated probabilities: Is it best to use words, numbers or both?

Organizations tasked with communicating expert judgments couched in uncertainty often use numerically bounded linguistic probability schemes to standardize the meaning of verbal probabilities. An experiment (N = 1,202) was conducted to ascertain whether agreement with such a scheme was better when probabilities were presented verbally, numerically or in a combined “verbal + numeric” format. Across three agreement measures, the numeric and combined formats outperformed the verbal format and also yielded better discrimination between low and high probabilities and were less susceptible to the fifty-fifty blip phenomenon. The combined format did not confer any advantage over the purely numeric format. The findings indicate that numerically bounded linguistic probability schemes are an ineffective means of communicating information about probabilities to others and they call into question recommendations for use of the combined format for delivering such schemes.