Causal Interpretations of Correlational Evidence Regarding Violence.

Abstract

Inferring causation from correlation can lead to erroneous explanations of violent behavior and the development and implementation of ineffective or even harmful interventions and policies. This article explores the inferences that violence researchers draw from evidence related to violent offending. We invited authors of articles published in violence journals to complete an online survey in which they were asked to identify a factor that may be a cause of violence, cite a study that demonstrates the factor is associated with violence, and provide their inferences from that study. We read each study and coded its research design (description of a sample [n = 9], cross-sectional/retrospective non-experiment [n = 18], single-wave longitudinal non-experiment [n = 10], multi-wave longitudinal non-experiment [n = 0], or randomized experiment [n = 5]) and the appropriate inferences (inter-rater reliability was adequate; κ = 0.73-1.00). Reassuringly, participants (N = 42; 57.1% in United States; 59.5% women) rarely indicated that their identified study demonstrated that their factor was a cause of violence (0.0%-16.7%) when the study was not a randomized experiment. However, many participants failed to acknowledge any plausible alternate interpretations (e.g., reverse causality, third variable) of the results from non-experimental studies (50.0%-88.9%). Moreover, most participants incorrectly selected a causal implication as following from the results of non-experimental studies (77.8%-100%). Our results suggest that even among authors of articles published in peer-review scientific journals on violence, many appear to infer causation from correlation.