Instrumental variables is a popular approach for causal inference in education when randomization of treatment is not feasible. Using a first-year college program as a running example, this article reviews the five assumptions that must be met to successfully use instrumental variables to estimate a causal effect with observational data: SUTVA,…

In Roberts and Strayer (1996), we reported that emotional expressiveness and anger were important predictors of empathy for school-age children, and that empathy strongly predicted prosocial behaviors aggregated across methods and sources. In this paper, we report how empathy was associated with direct observations of anger and aggression in peer…