Recent research contends that the behavioral immune system, operating largely outside conscious awareness, motivates individuals to exhibit higher levels of prejudice toward unfamiliar out-groups. This research finds that individual variance in disgust sensitivity correlates with support for political policies that facilitate the avoidance of out-groups. We were interested in developing less intrusive indicators of disgust sensitivity via olfactory measures (i.e., ratings of disgusting odors) and behavioral measures (e.g., willingness to touch disgusting objects) and studying the association between measures of disgust sensitivity and in-group bias among children and adults. We submitted a registered report to conduct this research and received an in-principle acceptance. Unfortunately, unforeseen events impaired our data collection, leaving us with a limited sample (nchildren = 32, nadults = 29) and reducing our ability to draw reliable conclusions from our results. In this essay, we describe our motivation and plan of research, the events that made completing the research impossible, and our preliminary results. In doing so, we hope to offer support for studying the effects of the behavioral immune system, even in ways that we did not originally plan. We conclude with a reflection on the value of registered reports for advancing science.