title: Appropriate questions about causal inference from "Direction of Causation" analyses.
authors.affiliation: Department of Psychology, University of Virginia, Charlottesville, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: McArdle
mesh_terms: D015984:Causality; D003627:Data Interpretation, Statistical; D006801:Humans; D008957:Models, Genetic; D018433:Twin Studies as Topic; D014427:Twins / Q000235:genetics*