Inducing age-related disgust increases negative attitudes towards the elderly

All participants were recruited through the online research platform Prolific Academic (Prolific Academic Ltd, London). The experiment was conducted with eligibility limited to participants with a UK nationality, as previous cross-cultural studies have shown that different parts of the world have different values, such as the focus on filial piety, which can influence attitudes towards older people (North & Fiske, 2015). Participants between the ages of 18 and 50 were selected to minimize the effect of in-group biases (Martens et al., 2005). Additionally, all participants were required to have English as their first language as the study involved reading vignettes, which aimed to reduce the risk of misinterpretation and misunderstanding.
An a priori power analysis using G*Power (version 3.1; Faul et al., 2009) for an ANCOVA<strong> </strong>with three independent groups and four covariates, with <em>a = </em>0.05, power = 0.8, and an effect size of<em> = </em>0.25, recommended a minimum sample size of <em>n </em>= 269. An extra 20% was added to the minimum sample size to account for potential incomplete and/or bad data (Galesic, 2006), bringing the required sample size to n = 324. Ultimately, <em>n</em> = 324 participants completed the study with 49.7% identifying as female and 50% as male and 0.3% identifying as other. The mean (<em>M</em>) age of the participants was 34.79 (standard deviation, [<em>SD</em>] = 7.40) years. In terms of ethnicity, 91.7% of the participants identified as White, 2.2% as Asian or Asian British, 1.5% as Black, Black British, Caribbean, or African, 0.9% as Arab and 3.7% as Mixed or multiple ethnic groups. Participants were compensated £1.50 for the 10-min duration of the study, in line with guidance from Prolific Academic. The study was approved by the institutional Research Ethics Committee (053946).
For further information on the study, please see the attached README file.