Undermining optimistic denial reactions to domestic and campus emergency warning messages

Generalizability of heterogeneous treatment effect estimates across samples

The extent to which survey experiments conducted with nonrepresentative convenience samples are generalizable to target populations depends critically on the degree of treatment effect heterogeneity. Recent inquiries have found a strong correspondence between sample average treatment effects estimated in nationally representative experiments and in replication studies conducted with convenience samples. We consider here two possible explanations: low levels of effect heterogeneity or high levels of effect heterogeneity that are unrelated to selection into the convenience sample. We analyze subgroup conditional average treatment effects using 27 original-replication study pairs (encompassing 101,745 individual survey responses) to assess the extent to which subgroup effect estimates generalize. While there are exceptions, the overwhelming pattern that emerges is one of treatment effect homogeneity, providing a partial explanation for strong correspondence across both unconditional and conditional average treatment effect estimates.

Denial of a sleep deprivation message: situational and dispositional influences on message rejection

Two studies investigated situational and dispositional influences on rejection of a sleep deprivation warning message for young adults. The hassle of protection (Study 1) and the self-relevance of the problem (Study 2) were manipulated; the disposition to use denial (threat orientation) for warning messages was measured. In both studies, it was found that both dispositional denial and the situational manipulation (more protection-hassle or self-relevance) showed at least one denial effect by reducing perceived susceptibility, perceived severity, or credibility. Indirect (mediational) effects were tested with the bootstrap method. In Study 1, judgments of credibility and severity mediated the effects of the hassle manipulation and denial orientation on message outcomes. In Study 2, credibility mediated the effects of the self-relevance manipulation and denial orientation on message outcomes of intentions to change and priority given to sleep. These studies show that both situational and dispositional sources of denial work in similar ways by lowering key message judgments and that the lower judgments lead to less priority given to a health risk and lower intentions to protect oneself.