Popular measurement invariance testing procedures for latent constructs evaluated by multiple indicators in distinct populations are revisited and discussed. A frequently used test of factor loading invariance is shown to possess serious limitations that in general preclude it from accomplishing its goal of ascertaining this invariance. A process…

Participants completed a before/after and a similar/different relational task, using the Implicit Relational Assessment Procedure (IRAP), and subsequently took the Kaufman Brief Intelligence Test (K-BIT). For each relational task, response latencies were measured first on consistent trials, where participants responded in accordance with…

Although people with autism spectrum disorders (ASD) often have severe problems with pragmatic aspects of language, little is known about their pragmatic reasoning. We carried out a behavioral study on high-functioning adults with autistic disorder (n = 11) and Asperger syndrome (n = 17) and matched controls (n = 28) to investigate whether they…

The purpose of the present study was to determine which behavioral and physical phenotypes would be most likely to divide the ASD population into discrete subgroups. The taxometric methods of Maximum Covariance (MAXCOV) and Minus Mean Below A Cut (MAMBAC) were employed to test for categorical versus continuous variation of each phenotype across…

The present study, based on the work of Dweck (2000) and her description of helpless and mastery-orientated children, was designed to find a new, simple and economic way of assessing helplessness while testing a child's intelligence. Two hundred and thirty-two Austrian grammar-school children, previously classified as either helpless or…

Despite its avowed goal of understanding individual behavior, the field of behavior analysis has largely ignored the determinants of consistent differences in level of performance among individuals. The present article discusses major findings in the study of individual differences in intelligence from the conceptual framework of a functional…