From group diffusion to ratio bias: Effects of denominator and numerator salience on intuitive risk and likelihood judgments
The group-diffusion effect is the tendency for people to judge themselves to be less likely to experience a negative outcome as the total number of people exposed to the threat increases — even when the probability of the outcome is explicitly presented (Yamaguchi, 1998). In Experiment 1 we replicat...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Cambridge University Press
2009-10-01
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| Series: | Judgment and Decision Making |
| Subjects: | |
| Online Access: | https://www.cambridge.org/core/product/identifier/S1930297500003971/type/journal_article |
| _version_ | 1797695992520245248 |
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| author | Paul C. Price Teri V. Matthews |
| author_facet | Paul C. Price Teri V. Matthews |
| author_sort | Paul C. Price |
| collection | DOAJ |
| description | The group-diffusion effect is the tendency for people to judge themselves to be less likely to experience a negative outcome as the total number of people exposed to the threat increases — even when the probability of the outcome is explicitly presented (Yamaguchi, 1998). In Experiment 1 we replicated this effect for two health threat scenarios using a variant of Yamaguchi’s original experimental paradigm. In Experiment 2, we showed that people also judge themselves to be less likely to be selected in a lottery as the number of people playing the lottery increases. In Experiment 3, we showed that explicitly presenting the number of people expected to be selected eliminates the group-diffusion effect, and in Experiment 4 we showed that presenting the number expected to be affected by a health threat without presenting the total number exposed to the threat produces a reverse effect. We propose, therefore, that the group-diffusion effect is related to the ratio bias. Both effects occur when people make risk or likelihood judgments based on information presented as a ratio. The difference is that the group-diffusion effect occurs when the denominator of the relevant ratio is more salient than the numerator, while the ratio bias occurs when the numerator is more salient than the denominator. |
| first_indexed | 2024-03-12T03:20:15Z |
| format | Article |
| id | doaj.art-81c59b37dfbf40b299682583c831111e |
| institution | Directory Open Access Journal |
| issn | 1930-2975 |
| language | English |
| last_indexed | 2024-03-12T03:20:15Z |
| publishDate | 2009-10-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Judgment and Decision Making |
| spelling | doaj.art-81c59b37dfbf40b299682583c831111e2023-09-03T14:02:37ZengCambridge University PressJudgment and Decision Making1930-29752009-10-01443644610.1017/S1930297500003971From group diffusion to ratio bias: Effects of denominator and numerator salience on intuitive risk and likelihood judgmentsPaul C. Price0Teri V. Matthews1California State University, FresnoCalifornia State University, FresnoThe group-diffusion effect is the tendency for people to judge themselves to be less likely to experience a negative outcome as the total number of people exposed to the threat increases — even when the probability of the outcome is explicitly presented (Yamaguchi, 1998). In Experiment 1 we replicated this effect for two health threat scenarios using a variant of Yamaguchi’s original experimental paradigm. In Experiment 2, we showed that people also judge themselves to be less likely to be selected in a lottery as the number of people playing the lottery increases. In Experiment 3, we showed that explicitly presenting the number of people expected to be selected eliminates the group-diffusion effect, and in Experiment 4 we showed that presenting the number expected to be affected by a health threat without presenting the total number exposed to the threat produces a reverse effect. We propose, therefore, that the group-diffusion effect is related to the ratio bias. Both effects occur when people make risk or likelihood judgments based on information presented as a ratio. The difference is that the group-diffusion effect occurs when the denominator of the relevant ratio is more salient than the numerator, while the ratio bias occurs when the numerator is more salient than the denominator.https://www.cambridge.org/core/product/identifier/S1930297500003971/type/journal_articlerisk judgmentprobability judgmentgroup-diffusion effectratio bias |
| spellingShingle | Paul C. Price Teri V. Matthews From group diffusion to ratio bias: Effects of denominator and numerator salience on intuitive risk and likelihood judgments Judgment and Decision Making risk judgment probability judgment group-diffusion effect ratio bias |
| title | From group diffusion to ratio bias: Effects of denominator and numerator salience on intuitive risk and likelihood judgments |
| title_full | From group diffusion to ratio bias: Effects of denominator and numerator salience on intuitive risk and likelihood judgments |
| title_fullStr | From group diffusion to ratio bias: Effects of denominator and numerator salience on intuitive risk and likelihood judgments |
| title_full_unstemmed | From group diffusion to ratio bias: Effects of denominator and numerator salience on intuitive risk and likelihood judgments |
| title_short | From group diffusion to ratio bias: Effects of denominator and numerator salience on intuitive risk and likelihood judgments |
| title_sort | from group diffusion to ratio bias effects of denominator and numerator salience on intuitive risk and likelihood judgments |
| topic | risk judgment probability judgment group-diffusion effect ratio bias |
| url | https://www.cambridge.org/core/product/identifier/S1930297500003971/type/journal_article |
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