Brian P. Meier

Research shows that perceived naturalness can bias beliefs about the positivity of items such as food, human talent, and vaccines. Yet, this research focuses on self-reports, which leaves open the implications it has for behavior. In four studies ( N = 492), we tested if perceived naturalness impacts trivial and meaningful behaviors. Participants were asked to consume a purported natural/synthetic performance drink (Study 1), test a purported natural/synthetic drug that would be injected (Study 2), eat chocolate containing a purported natural/synthetic cocoa described as causing stomach discomfort (Study 3), or choose a sticker purportedly made with natural/synthetic ink (Study 4). A significant majority of participants (66%–84%) chose and followed through with the natural versus synthetic option. Perceived naturalness guided behavior in contexts involving little (sticker choice) to substantial (drug injection) potential consequences. Self-reports can weakly predict behaviors, but the results revealed that perceived naturalness biases self-reports and behaviors in a similar fashion.

Is disease risk perception accurately calibrated among the unvaccinated? People shift their attitudes to rationalize their choices, so those who choose to be unvaccinated may be motivated to feel less at risk. In three studies (total N = 1446), we asked Americans how worried they were about catching/spreading influenza and COVID‐19 and whether they were vaccinated against those diseases. Unvaccinated participants felt less at risk of catching/spreading the diseases they were unvaccinated against than vaccinated participants. For instance, unvaccinated participants felt ∼24% less at risk of catching/spreading COVID‐19 and had ∼28% stronger intention to engage in activities that carried a high risk of COVID‐19 transmission (Study 3). Overall, those who choose to be the most vulnerable to disease feel and act the least vulnerable.

Past research with North American participants has demonstrated a naturalness bias in the medical context: people prefer natural drugs to synthetic drugs under a variety of situations. Does such a bias exist in other countries (such as China) where cultural values and practices are quite different from those in the United States? We conducted 3 studies ( N = 1,927) to investigate the naturalness bias with drugs and vaccines across cultures with American, Canadian, and Chinese participants. In studies 1A and 1B, participants chose or rated drugs (natural v. synthetic) for a hypothetical medical issue. The drugs were presented as having identical effectiveness and side effect profiles. Study 2 focused on a different medical context, vaccines, and required participants to rate their likelihood of taking vaccines (made from either more natural or more synthetic ingredients) for a harmful virus. The naturalness bias occurred across cultures in studies 1A and 1B, although it was not significant among Chinese participants in study 1B. In study 2, Chinese participants showed a stronger naturalness bias than Americans did, and safety concerns mediated the effect. Perceived safety accounted for the naturalness bias among Americans and Canadians, but did so only among Chinese in study 2. Overall, the results suggest that the naturalness bias in drug and vaccine decision making occurs across cultures, but Chinese participants may be more sensitive to the medical context. Highlights: The naturalness bias — preferring natural to synthetic drugs or vaccines — occurred across cultures (Americans, Canadians, and Chinese). Chinese participants showed a stronger naturalness bias than Americans did when the medical context was focused on vaccination, and safety concerns mediated this effect. The naturalness bias may influence medical decision making across cultures, but Chinese participants may be more sensitive to naturalness in a vaccine context.

Research reveals a bias for natural versus synthetic drugs. We sought to determine if this bias is associated with religiosity. Three cross-sectional studies (N = 1399 U.S. participants) were conducted to examine the impact of religiosity on the naturalness bias in the drug and vaccine domains. We assessed measures of religiosity, preferences for natural versus synthetic drugs and vaccines in hypothetical scenarios, and a health-related behavior (COVID-19 vaccination status). The results revealed that participants high versus low in religiosity had stronger preferences for natural versus synthetic drugs and vaccines. Furthermore, participants high versus low in religiosity were less likely to have taken the COVID-19 vaccine, and the natural drug bias was a mediator of this effect. Overall, participants higher in religiosity had a stronger preference for natural versus synthetic drugs and vaccines, and this preference had implications for health behavior.