Local and global processing: observations from a remote culture

In Experiment 1, a normal adult population drawn from a remote culture (Himba) in northern Namibia made similarity matches to [Navon, D. (1977). Forest before trees: The precedence of global features in visual perception. Cognitive Psychology, 9, 353-383] hierarchical figures. The Himba showed a local bias stronger than that has been previously observed in any other non-clinical human population. However, in Experiment 2, their recognition of normal or distorted ("Thatcherized") faces did not appear to have been affected by their attention to detail as has been suggested for autistic populations. The data are consistent with a cultural/experiential origin for population differences in local processing and suggest that attention to the local and global properties of stimuli may differ for hierarchical figures and faces.     

Patients suffering from nonspecific work-related upper extremity disorders exhibit insufficient movement strategies

The purpose of this research was to investigate whether patients experiencing nonspecific complaints of the forearm caused by sustained use of the personal computer exhibit deviant movement strategies as compared to healthy participants. Patients (N=10) and controls (N=24) performed a graphical aiming task combined with an auditory memory task. Force production (pen pressure), kinematic- and performance variables were recorded. During a trial, the control group gradually increased pen pressure from the stationary phases to the dynamic phase. The patients increased their pen pressure much more abruptly and to such a degree that the final pressure during real-time movement far exceeded that of the controls. Memory load led to a greater increase of pen pressure from the stationary phase to the dynamic phase in the patient group. Patients further displayed longer reaction times. The results are discussed within the framework of our recent theory on the role of neuromotor noise in the regulation of task performance under conditions of stress.     

Color categories: evidence for the cultural relativity hypothesis

The question of whether language affects our categorization of perceptual continua is of particular interest for the domain of color where constraints on categorization have been proposed both within the visual system and in the visual environment. Recent research (Roberson, Davies, & Davidoff, 2000; Roberson et al., in press) found substantial evidence of cognitive color differences between different language communities, but concerns remained as to how representative might be a tiny, extremely remote community. The present study replicates and extends previous findings using additional paradigms among a larger community in a different visual environment. Adult semi-nomadic tribesmen in Southern Africa carried out similarity judgments, short-term memory and long-term learning tasks. They showed different cognitive organization of color to both English and another language with the five color terms. Moreover, Categorical Perception effects were found to differ even between languages with broadly similar color categories. The results provide further evidence of the tight relationship between language and cognition.     

A standard for test reliability in group research

Many authors adhere to the rule that test reliabilities should be at least .70 or .80 in group research. This article introduces a new standard according to which reliabilities can be evaluated. This standard is based on the costs or time of the experiment and of administering the test. For example, if test administration costs are 7 % of the total experimental costs, the efficient value of the reliability is .93. If the actual reliability of a test is equal to this efficient reliability, the test size maximizes the statistical power of the experiment, given the costs. As a standard in experimental research, it is proposed that the reliability of the dependent variable be close to the efficient reliability. Adhering to this standard will enhance the statistical power and reduce the costs of experiments.     

The Prediction of Family Interaction from a Battery of Projective Techniques

This study first explored the adequacy of items on the Rorschach Rating Scale (RRS), which measures Rorschach constructs from a variety of scoring systems. Analyses determined that all items had an adequate capacity to differentiate people and none were clearly redundant. At the same time, the current version of the RRS requires good reading comprehension skills for accurate completion (13th grade level). Next, we developed two sets of RRS scales. Factor analysis of observer ratings (N = 234) indicated the RRS contained six broad, empirically derived factors. In addition, 19 conceptually derived scales were developed from the RRS item pool. Both sets of scales were evaluated for reliability and then compared to the Big Five model (B5M) of personality through a series of factor and regression analyses. Results indicated that RRS scales do not provide adequate definition of all B5M dimensions and B5M scales do not provide adequate definition of all RRS dimensions. We discuss the place of psychotic processes within a comprehensive model of personality and other implications from these findings.     

A 21st century cognitive portrait of the Himba,a remote people of Namibia

This research sketches the cognitive portrait of the Himba, a remote population from Northern Namibia living in a non-industrial society almost completely devoid of modern artefacts. We compared the Himba sample to a French sample, exploring cognitive reflection, moral judgement, cooperative behaviour, paranormal beliefs, and happiness. We looked for both differences and similarities across cultures, and for the way cognitive functioning is associated with a range of demographic variables. Results showed some important group differences, with the Himba being more intuitive, more religious, happier, and less utilitarian than the French participants. Further, the predictors of these beliefs and behaviours differed between the two groups. The present results provide additional support to the recent line of research targeting cultural variations and similarities, and call for the need to expand psychology research beyond the Western world.     

Exposure to an urban environment alters the local bias of a remote culture

There is substantial evidence that populations in the Western world exhibit a local bias compared to East Asian populations that is widely ascribed to a difference between individualistic and collectivist societies. However, we report that traditional Himba - a remote interdependent society - exhibit a strong local bias compared to both Japanese and British participants in the Ebbinghaus illusion and in a similarity-matching task with hierarchical figures. Critically, we measured the effect of exposure to an urban environment on local bias in the Himba. Even a brief exposure to an urban environment caused a shift in processing style: the local bias was reduced in traditional Himba who had visited a local town and even more reduced in urbanised Himba who had moved to that town on a permanent basis. We therefore propose that exposure to an urban environment contributes to the global bias found in Western and Japanese populations.