In an anonymous 4-person economic game, participants contributed more money to a common project (i.e., cooperated) when required to decide quickly than when forced to delay their decision (Rand, Greene & Nowak, 2012), a pattern consistent with the social heuristics hypothesis proposed by Rand and colleagues. The results of studies using time pressure have been mixed, with some replication attempts observing similar patterns (e.g., Rand et al., 2014) and others observing null effects (e.g., Tinghög et al., 2013; Verkoeijen & Bouwmeester, 2014). This Registered Replication Report (RRR) assessed the size and variability of the effect of time pressure on cooperative decisions by combining 21 separate, preregistered replications of the critical conditions from Study 7 of the original article (Rand et al., 2012). The primary planned analysis used data from all participants who were randomly assigned to conditions and who met the protocol inclusion criteria (an intent-to-treat approach that included the 65.9% of participants in the time- pressure condition and 7.5% in the forced-delay condition who did not adhere to the time constraints), and we observed a difference in contributions of −0.37 percentage points compared with an 8.6 percentage point difference calculated from the original data. Analyzing the data as the original article did, including data only for participants who complied with the time constraints, the RRR observed a 10.37 percentage point difference in contributions compared with a 15.31 percentage point difference in the original study. In combination, the results of the intent-to-treat analysis and the compliant-only analysis are consistent with the presence of selection biases and the absence of a causal effect of time pressure on cooperation.

This study sought to identify stigma differences between HIV/AIDS and other sexually transmitted infections (STIs). Interviewees from Alabama, USA (n=537) rated two types of stigma (damage to social reputation and “moral weakness”) for seven infections ranging from “nuisance” conditions (e.g., pubic lice) to life-threatening disease (e.g., HIV/AIDS). When asked which of the seven STIs would be most damaging to reputation, 74.8% of respondents chose HIV/AIDS. However, when asked to choose which STI represented moral weakness in infected persons, HIV/AIDS was rated as significantly lower than the other STIs, which suggests that HIV/AIDS is perceived differently than non-HIV STIs. This study addresses the possibility that advances in public awareness of HIV/AIDS have not necessarily been extrapolated into awareness of other STIs. Clinicians should be aware of these high levels of stigma as potential barriers to treatment for all STIs. Public health officials should consider the impact of undifferentiated stigma on STI prevention messages.