M. R. Nash, T. L. Hulsey, M. C. Sexton,
T. L. Harralson, and W. Lambert (1993) reported on the effects of
controlling for family environment when studying sexual abuse
sequelae. Sexual abuse history was associated with elevated Minnesota
Multiphasic Personality Inventory and Rorschach scores in a sample of
105 women, but many of the reported differences disappeared when a
Family Functioning Scale score was used as a covariate. The present
article considers the findings of Nash et al. in terms of the
theoretical and statistical constraints placed on analysis of
covariance and other partializing procedures. Because family
dysfunction is not always causally antecedent to sexual abuse, and
given the quasi-experimental quality of most abuse research, the use
of covariate techniques to test hypotheses about the causal role of
family environment in the impacts of sexual abuse may be ill
advised. Analyses of a 2,964-subject data set illustrate these
concerns.