Psychological essentialism and cultural variation: children's beliefs about aggression in the United States and South Africa

The present study compared indigenous South African versus African‐American schoolchildren's beliefs about aggression. Eighty 7–9 year olds (40 from each country) participated in interviews in which they were asked to make inferences about the stability, malleability, and causal origins of aggressive behaviour. Although a minority of participants from both countries endorsed essentialist beliefs about aggression, South African children were more likely than American children to do so. Results also revealed some degree of coherence in children's patterns of beliefs about aggression, such that children responded across superficially different measures in ways that appear theoretically consistent. The authors consider these findings in light of debates concerning the role of cultural forces in shaping person perception. Copyright © 2007 John Wiley & Sons, Ltd.     

Development of the positive–negative asymmetry effect: in‐group exclusion norm as a mediator of children's evaluations on negative attributes

Two studies were conducted that go beyond previous research by examining when and why children might show intergroup bias in the attribution of positive, but not negative traits (PNAE: the positive–negative asymmetry effect, Mummendey & Otten, 1998, European review of social psychology, Vol. 9). In Study 1 (n = 107) children completed a ‘mixed’ trait attribution task in a dichotomous group context. As predicted there was a developmental trend between 7 and 12 years of age in the PNAE. The 7‐year olds were the only age group not to show the effect. Study 1 also found a quadratic developmental trend in children's national intergroup bias. Study 2 (n = 62) replicated the developmental path of the PNAE found in Study 1 using a wider age range of 6–16 years. This study used a ‘mixed’ list of traits which were not only antonyms and a procedure that made the positive and negative trait dimensions explicitly independent. Significantly, Study 2 found in‐group exclusion norm partially mediated the development of the PNAE. These findings support an account of the positive–negative asymmetry effect based upon normative processes. Copyright © 2006 John Wiley & Sons, Ltd.     

Human Performance Under Progressive Ratio Contingencies

The Psychological Record - Ten human subjects experienced a progressive ratio schedule under three different reinforcement conditions; (a) 20-point increments on a computer screen for each ratio...     

Motor perseverative behavior in adult stutterers and nonstutterers

The performances of 22 adult stutterers and 22 adult nonstutterers on motor tasks requiring the graphic reproduction of a sequence of alternating figures following the production of a series of nonalternating figures were studied. The finding that there were no differences in the performance of the two groups on the alternating motor tasks was interpreted as challenging the validity of previous observations that motor perseverative behavior exists in stutterers and is indicative of a central neurological deficit in that population.     

Facial expression analysis with AFFDEX and FACET: A validation study

The goal of this study was to validate AFFDEX and FACET, two algorithms classifying emotions from facial expressions, in iMotions’s software suite. In Study 1, pictures of standardized emotional facial expressions from three databases, the Warsaw Set of Emotional Facial Expression Pictures (WSEFEP), the Amsterdam Dynamic Facial Expression Set (ADFES), and the Radboud Faces Database (RaFD), were classified with both modules. Accuracy (Matching Scores) was computed to assess and compare the classification quality. Results show a large variance in accuracy across emotions and databases, with a performance advantage for FACET over AFFDEX. In Study 2, 110 participants’ facial expressions were measured while being exposed to emotionally evocative pictures from the International Affective Picture System (IAPS), the Geneva Affective Picture Database (GAPED) and the Radboud Faces Database (RaFD). Accuracy again differed for distinct emotions, and FACET performed better. Overall, iMotions can achieve acceptable accuracy for standardized pictures of prototypical (vs. natural) facial expressions, but performs worse for more natural facial expressions. We discuss potential sources for limited validity and suggest research directions in the broader context of emotion research.     

Orthographic neighborhood and concreteness effects in the lexical decision task

The experiment reported here investigated the sensitivity of concreteness effects to orthographic neighborhood density and frequency in the visual lexical decision task. The concreteness effect was replicated with a sample of concrete and abstract words that were not matched for orthographic neighborhood features and in which concrete words turned out to have a higher neighborhood density than abstract words. No consistent effect of concreteness was found with a sample of concrete and abstract words matched for orthographic neighborhood density and frequency and having fewer neighbors and higher-frequency neighbors than the words of the first sample. Post hoc analyses of the results showed that orthographic neighborhood density was not a nuisance variable producing a spurious effect of concreteness but, instead, that the existence of higher-frequency neighbors constitutes a necessary condition for concreteness effects to appear in the lexical decision task. This finding is consistent with the hypothesis that semantic information is accessed and used to generate the responses in lexical decision when inhibition from orthographic forms delays the target word recognition.     

Recognition memory for text and melody of songs after unilateral temporal lobe lesion: evidence for dual encoding.

The role of left and right temporal lobes in memory for songs (words sung to a tune) was investigated. Patients who had undergone focal cerebral excision for the relief of intractable epilepsy along with normal control subjects were tested in 2 recognition memory tasks. The goal of Experiment 1 was to examine recognition of words and of tunes when they were presented together in an unfamiliar song. In Experiment 2, memory for spoken words and tunes sung without words was independently tested in 2 separate recognition tasks. The results clearly showed (a) a deficit after left temporal lobectomy in recognition of text whether sung to a tune or spoken without musical accompaniment, (b) impaired melody recognition when the tune was sung with new words following left or right temporal lobectomy and (c) impaired melody recognition in the absence of lyrics following right but not left temporal lobectomy. The different role of each temporal lobe in memorizing songs provides evidence for the use of dual memory codes. The verbal code is consistently related to left temporal lobe structures, whereas the melodie code my depend on either or both temporal lobe mechanisms, according to the type of encoding involved.     

Social class and interpersonal trust: Partner's warmth,external threats and interpretations of trust betrayal

The present research investigated the effects of social class on interpersonal trust. In a series of experiments, we showed how the contextualist socio-cognitive tendencies of the lower class and the solipsistic tendencies of the upper class were reflected in their trusting attitudes and behaviors. In Study 1 (N = 491), upper class individuals expressed the same levels of trust towards all partners, while lower class individuals adjusted their trust choices to the affect-rich information about their interaction partner and trusted warm partners more than cold partners. The results of Study 2 (N = 210) showed that when threatened, lower class individuals had generally less trusting attitudes, while upper class members were equally trusting as in a neutral situation. Study 3 (N = 200) revealed that upper class individuals explained a betrayal of their trust with dispositional factors to a higher degree than lower class individuals. We discuss how these differences contribute to perpetuating the disadvantage of the lower class.