The primary aims of this study were four-fold. The first aim was to examine which of the three alternative models of irritability provided a... Show moreThe primary aims of this study were four-fold. The first aim was to examine which of the three alternative models of irritability provided a better fit to the data. The second aim was to further refine the model of irritability by examining the gender and age invariance of the best-fitting models. After establishing which model showed the best fit, the third aim was to empirically examine the reliability and validity of the irritability scale that included items from both temperament and psychopathology scales. Finally, the fourth aim was to examine the rank-order stability and mean-levels of irritability between the ages of 4 and 6. Participants included a diverse, community sample of 796 children and their parents. Irritability, frustration, and anger were measured by selected items from temperament and psychopathology scales, including the Children’s Behavior Questionnaire (CBQ; Rothbart et al., 2001), Child Symptom Inventory (CSI; Gadow & Sprafkin, 1994, 1997), and Eyberg Behavior Inventory (ECBI; Eyberg & Pincus, 1999). Results indicate that the three-factor and two-factor measurement models were viable, alternative models at age 4. Contrary to expectation, neither the three-factor nor the twofactor models were invariant for both genders combined, or between the ages of 4 and 6. Based on the definition of irritability in the three-factor model, the irritability scale demonstrated adequate internal consistency, convergent validity, and divergent validity. Finally, the rank-order stability of irritability was in the moderate range during the period from preschool through kindergarten and formal school entry, but mean-levels of irritability did not differ across time. Implications of the findings and suggestions for future research are discussed. PH.D in Psychology, December 2013 Show less
