Small deviations from bilateral symmetry (fluctuating asymmetries) are cues to fitness differences in some animals. Therefore, researchers have considered whether animals use these small asymmetries as visual cues to determine appropriate behavioral responses (e.g., mate preferences). However, there have been few systematic studies of animals'…

Previous studies have shown that after being trained on A-B and A-C match-to-sample tasks, adults match not only same-class B and C stimuli (equivalence) but also BC compounds with same-class elements and with different-class elements (BC-BC). The assumption was that the BC-BC performances are based on matching equivalence and nonequivalence…

Three papers--comments, a reply to comments, and a rejoinder--discussing a conclusion about the nature of general intelligence based on the size loadings of a psychomotor test of discrimination reaction time are presented. The use of Spearman's "g" is the center of the controversy. (TJH)

This study measured the differential effects of simplified and typical verbal antecedents on acquisition of picture discriminations for four preschool children with autism. During baseline probes, participants emitted no correct selection responses to pictures of common stimuli during either simplified or typical verbal antecedent conditions.…

An experimental group (n=6) of student dentists received discrimination training and self-evaluation exercises on 4 waxing projects and 4 handpiece projects over 13 hours. An equivalent "conventional" group (n=7) received verbal feedback with models on 7 waxing projects over 13 hours. The experimental group outperformed the conventional…