The integration of continuous and discrete latent variable models: potential problems and promising opportunities

Structural equation mixture modeling (SEMM) integrates continuous and discrete latent variable models. Drawing on prior research on the relationships between continuous and discrete latent variable models, the authors identify 3 conditions that may lead to the estimation of spurious latent classes in SEMM: misspecification of the structural model, nonnormal continuous measures, and nonlinear relationships among observed and/or latent variables. When the objective of a SEMM analysis is the identification of latent classes, these conditions should be considered as alternative hypotheses and results should be interpreted cautiously. However, armed with greater knowledge about the estimation of SEMMs in practice, researchers can exploit the flexibility of the model to gain a fuller understanding of the phenomenon under study.     

Transfer of physical understanding in a non-tool-using parrot

Physical cognition has generally been assessed in tool-using species that possess a relatively large brain size, such as corvids and apes. Parrots, like corvids and apes, also have large relative brain sizes, yet although parrots rarely use tools in the wild, growing evidence suggests comparable performances on physical cognition tasks. It is, however, unclear whether success on such tasks is facilitated by previous experience and training procedures. We therefore investigated physical comprehension of object relationships in two non-tool-using species of captive neotropical parrots on a new means-end paradigm, the Trap-Gaps task, using unfamiliar materials and modified training procedures that precluded procedural cues. Red-shouldered macaws (Diopsittaca nobilis) and black-headed caiques (Pionites melanocephala) were presented with an initial task that required them to discriminate between pulling food trays through gaps while attending to the respective width of the gaps and size of the trays. Subjects were then presented with a novel, but functionally equivalent, transfer task. Six of eight birds solved the initial task through trial-and-error learning. Four of these six birds solved the transfer task, with one caique demonstrating spontaneous comprehension. These findings suggest that non-tool-using parrots may possess capacities for sophisticated physical cognition by generalising previously learned rules across novel problems.     

The positive and negative effects of anger on dispute resolution: evidence from electronically mediated disputes

Scholars have argued that anger expressed by participants in mediation is counterproductive; yet, there is also reason to believe that expressions of anger can be productive. The authors tested these competing theories of emotion by using data from online mediation. Results show that expression of anger lowers the resolution rate in mediation and that this effect occurs in part because expressing anger generates an angry response by the other party. However, when respondents are especially vulnerable, expressions of anger by the filer do not hinder settlement. The authors also examined precursors to anger, such as value of dispute and reputation, and the degree to which a focus on dispute resolution is reciprocated.     

Emotional,Sensitive, and Unfit for Office? Gender Stereotype Activation and Support Female Candidates

Women are underrepresented at all levels of elected office. It is suspected that gender stereotypes hinder the electoral success of female candidates, but empirical evidence is inconclusive on whether stereotypes have a direct effect on voting decisions. This empirical conflict stems, in part, from the assumption that voters automatically rely on gender stereotypes when evaluating female candidates. This study explicitly tests the assumption of automatic stereotype activation. I suggest that stereotype reliance depends on whether stereotypes have been activated during a campaign, and it is only when stereotypes are activated that they influence evaluations of female candidates. These hypotheses are tested with a survey experiment and observational analysis. The results show that campaign communication activates stereotypes when they otherwise might not be activated, thereby diminishing support for female candidates.     

RELATIONS BETWEEN PREDICTION- AND ESTIMATION-RESPONSES IN CUE-PROBABILITY LEARNING AND TRANSFER

B auer M arianne Relations between prediction- and estimation-responses in cue-probability learning and transfer. Scand. J. Psychol ., 1972, 13 , 198–207. —Comparisons were made between prediction- and estimation-responses, preceded by training with different types of responding and when task probabilities were shifted. The main results were: ( a ) differential effects of procedure of learning and shift in task structure on predictions and estimates support the hypothesis of two different processes, ( b ) estimates as indicators of probability learning reflect traits assumed to characterize the perception process, viz. sensitivity to shifts in probabilities, and robustness against influence from procedure of learning, and ( c ) prediction-responses were affected in the direction of more extreme responses by simultaneous estimation, which result strengthens the supposition that probability estimates are insufficient as indicators of the complete perception process in a prediction task.