Do monkeys compare themselves to others?

Social comparisons are a fundamental characteristic of human behaviour, yet relatively little is known about their evolutionary foundations. Adapting the co-acting paradigm from human research (Seta in J Pers Soc Psychol 42:281–291, 1982. doi: 10.1037//0022-3514.42.2.281), we examined how the performance of a partner influenced subjects’ performance in long-tailed macaques (Macaca fascicularis). Using parallel testing in touch screen setups in which subjects had to discriminate familiar and novel photographs of men and women, we investigated whether accuracy and reaction time were influenced by partner performance and relationship quality (affiliate vs. non-affiliate). Auditory feedback about the alleged performance of the co-actor was provided via playback; partner performance was either moderately or extremely better or worse than subject performance. We predicted that subjects would assimilate to moderately different comparison standards as well as to affiliates and contrast away from extreme standards and non-affiliates. Subjects instantly generalized to novel pictures. While accuracy was not affected by any of the factors, long reaction times occurred more frequently when subjects were tested with a non-affiliate who was performing worse, compared to one who was doing better than them (80 % quantile worse: 5.1, better: 4.3 s). For affiliate co-actors, there was no marked effect (worse: 4.4, better: 4.6 s). In a control condition with no auditory feedback, subjects performed somewhat better in the presence of affiliates (M = 77.8 % correct) compared to non-affiliates (M = 71.1 %), while reaction time was not affected. Apparently, subjects were sensitive to partner identity and performance, yet variation in motivation rather than assimilation and contrast effects may account for the observed effects.     

The Instructional Hierarchy as a Model of Stimulus Control over Student <Emphasis Type="Italic">and</Emphasis> Teacher Behavior: We're Close but are We Close Enough?

As a stage-based model of learning, the Instructional Hierarchy offers a useful heuristic for organizing research on effective instructional strategies at different levels of skill proficiency. In this paper, we summarize and highlight the unique contributions of each empirical study presented in the special issue. We describe common methodological features across the studies that likely contributed to intervention effectiveness, and present several implications for research and practice.     

Impossibility Results for Infinite-Electorate Abstract Aggregation Rules

Following Lauwers and Van Liedekerke (1995), this paper explores in a model-theoretic framework the relation between Arrovian aggregation rules and ultraproducts, in order to investigate a source of impossibility results for the case of an infinite number of individuals and an aggregation rule based on a free ultrafilter of decisive coalitions.     

Effect of local chemistry,structure and length scale of heterogeneities on the mechanical properties of a Ti45Cu40Ni7.5Zr5Sn2.5 bulk metallic glass

We report on distinct variations in local chemistry, structure and length scale of heterogeneous regions in Ti₄₅Cu₄₀Ni_7.5Zr₅Sn_2.5 fully glass rods of different diameters, i.e. rods subjected to different cooling rates. The present investigations indicate that the mechanical properties of the Ti₄₅Cu₄₀Ni_7.5Zr₅Sn_2.5 bulk metallic glass can be modified within a wide range of strength and plastic deformability by controlling the scale of the heterogeneous regions in the glass through appropriate variation of the cooling rate applied for solidification.     

Inverse deformation-fracture responses between dendrite and matrix in Ti-based nanostructure–dendrite composite

The room-temperature deformation and fracture mechanisms of Ti-based nanostructured alloys are investigated. The monolithic nanostructured alloy goes through a shear banding???kinetic softening vicious cycle and exhibits very limited plasticity. The nanostructure–dendrite composite exhibits large plasticity while retaining a very high strength. Three fracture modes, namely shear fracture of the nanostructured matrix phase, normal ductile fracture of the dendritic phase and the peeling off of the dendrites from the matrix, are clearly observed. With increasing deformation, the nanostructured matrix is kinetically softened while the dendrite phase is work hardened. The inverse deformation responses and the interaction between the nanostructured matrix and the dendrites can effectively retard the inhomogeneous shear deformation of the nanostructured phase and lead to a large plasticity.     

Fokaltherapie

In many psychodynamic short therapy methods, the patient and therapist formulate a central conflict, the so-called focus, at the beginning of therapy. In the following therapy sessions,both concentrate on dealing with this focus. In practice, therapists are faced with the question of how they could organize the concrete work with the focus in the most useful manner.The following article presents a clinical study which examines the influence of the therapist's verbalization of the focus on the success of therapy. Results showed that the therapists in the group having a more successful therapy outcome addressed the focus significantly more often and verbalized it in a more complex and interpersonal manner than the therapists in the group with a less successful therapy outcome.     

The Effects of Alternate Forms of Performance Feedback on Elementary-Aged Students’ Oral Reading Fluency

Within the context of a brief experimental design, the current study examined the effects of providing two different types of performance feedback, performance feedback on words read correctly (PFWC) and performance feedback on words read incorrectly (PFWI), on the oral reading fluency of six elementary-aged students. For all of the participants, PFWI resulted in higher levels of oral reading fluency than PFWC. In addition, for a majority of the participants, PFWC resulted in lower levels of oral reading errors than PFWI. These results suggest that providing students with performance feedback on the number or words read correctly may enhance the reading fluency of students experiencing reading difficulties. The implications of these results for intervention selection are discussed.