Callous-unemotional traits with mental disorders in adolescents by two-way Log-ratio analysis

Abstract

Psychopathy is complex phenomenon associate to personality disorder that manifests at a relatively early age and tends to be relatively stable throughout life. Psychopathy in adolescents is currently being studied using the approach of callous-unemotional (CU) traits. Recent studies have shown that adolescents with these traits have different causal factors leading to their behavior problems and mental disorders. Here I propose to use the log-ratio analysis, for two-way contingency table, for assessing the correlation between CU traits and mental disorders in adolescents. The data are provided by H.E.R.A.C.L.E. Lab (Unicusano research center on health education) and obtained submitting to a sample of 689 high school students two questionnaires: The Inventory of Callous-Unemotional Traits (ICU) and The Strengths and Difficulties Questionnaire (SDQ)). In two-way tables obtained, an odds ratio reflects the likelihood that a ICU trait (callousness, uncaring and unemotional) will have with SDQ values (normal, borderline and abnormal). Log-ratio analysis presents many advantages, among which the computation and the visual representation in a biplot map of the odds ratio that allows the correlation in terms of distances between points.