In a recent meta-analysis, Rasmussen et al. [1] attempted to quantify the relationship between optimism and physical health. The authors reported an association between optimism and physical health of r = 0.17, which depended on whether subjective (r = 0.21) or objective (r = 0.11) physical health measures were used. These results were reported to be independent of whether studies were cross-sectional, longitudinal, or prospective (longitudinal with baseline control for physical health) or the type of covariates included. The authors concluded that optimism is a significant predictor of physical health outcomes and claimed that the inclusion of prospective studies bolstered the credibility of their findings and eliminated the possibility of reverse causality.