Parents Are Slightly Happier Than Nonparents, but Causality Still Cannot Be Inferred

research-article2013 PSSXXX10.1177/0956797613508561Nelson et al.Reply to Bhargava, Kassam, and Loewenstein Commentary Parents Are Slightly Happier Than Nonparents, but Causality Still Cannot Be Inferred: A Reply to Bhargava, Kassam, and Loewenstein (2014) Psychological Science 2014, Vol. 25(1) 303­–304 © The Author(s) 2013 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0956797613508561 pss.sagepub.com S. Katherine Nelson 1 , Kostadin Kushlev 2 , Elizabeth W. Dunn 2 , and Sonja Lyubomirsky 1 University of California, Riverside and 2 University of British Columbia Received 8/22/13; Accepted 9/20/13 We welcome Bhargava, Kassam, and Lowenstein’s (2014) commentary on our article (Nelson, Kushlev, English, Dunn, & Lyubomirsky, 2013). The question we addressed, however, is different from the one Bhargava and col- leagues posed. Although we slipped into using causal language in a few places, our primary aim was to exam- ine the bivariate relationship between parenthood and well-being. Motivated in part by media portrayals of par- ents who are “miserable” and who “hate parenting,” we simply asked whether happiness and parenthood can coexist. Our analyses revealed that, overall, when parents and nonparents were asked about their happiness levels, the parents were slightly happier. Other fields also use this approach; for example, many researchers have assessed the direct correlation between income and well- being, facilitating comparisons of data sets around the world (see Diener & Biswas-Diener, 2002, for a review). We did not try to examine the causal effect of parent- hood on well-being, because our correlational design precluded causal interpretation. Bhargava et al., by con- trast, aimed to test causality. However, their causal claim about the direction of the parenthood effect on well- being is entirely contingent on having a causal theoretical model—a model that assumes all causes of well-being correlated with parenthood are included (Cohen & Cohen, 1983). That model was never articulated. Instead, the authors used a convenient (and limited) set of demo- graphic variables (see their Note 3), undoubtedly leaving out important factors, such as child temperament and child age. We have recently moved beyond the simple “Are parents happier? ” question to trying to understand when, why, and how some parents are happier (or less happy) than nonparents (Nelson, Kushlev, & Lyubomirsky, Of course, parents’ marital status, age, and gender are also related to their well-being. We considered the Bhargava et al. approach of using these variables as covariates (as described in Nelson, Kushlev, English, et al., 2013, p. 4), but we instead examined how the asso- ciation between parenthood and well-being varies among these groups. Indeed, we did find evidence of modera- tion—parenthood, compared with nonparenthood, was associated with relatively greater well-being for male and middle-aged individuals and with lower well-being for young and single ones. The presence of these significant moderators “invalidate[s] the analysis of covariance method” (Cohen & Cohen, 1983, p. 320) used by Bhargava et al., which indicates violation of their analysis’s assump- tions. That is, once moderation is established for a par- ticular variable, treating it as a control in subsequent analyses is generally considered unacceptable (Elwert & Winship, 2010). According to Bhargava et al., concluding that parent- hood improves well-being is premature. We absolutely agree. No causal conclusions can be drawn—from our analyses or theirs. When disagreements emerge in behav- ioral research, it is important to demarcate the points of agreement and divergence. Notably, Bhargava et al. do not dispute our central claim—that, overall, parents are slightly happier than nonparents. However, disentan- gling the causal effect of parenthood remains an open and complex question that requires multiple triangulat- ing methodologies—not just comparing parents and Corresponding Author: S. Katherine Nelson, Department of Psychology, University of California, Riverside, 900 University Ave., Riverside, CA 92521 E-mail: snels007@ucr.edu