Conditioning on a Collider May or May Not Explain the Relationship Between Lower Neuroticism and Premature Mortality in the Study by Gale et al. (2017): A Reply to Richardson, Davey Smith, and Munafò (2019)
We (Gale et al., 2017) analyzed data on 321,456 UK Biobank participants to address why higher neuroticism is sometimes related to lower mortality (e.g., Korten et al., 1999). We noted that the studies that revealed an inverse relationship between neuroticism and mortality included self-rated health as a predictor, perhaps because it is associated with mortality, even when multiple objective measures of health status are included in models (for reviews, see Benyamini & Idler, 1999; Idler & Benyamini, 1997). We therefore tested whether including self-rated health, which was modestly related to neuroticism, rS = .23 (Gale et al., p. 1348), in a model changed the sign of the neuroticism–mortality relationship. We found that it did so and then set out to test two possible explanations for this phenomenon
