Personality and individual differences in plasticity

In the last few years, investigators have documented individual differences in many different types of behavioral plasticity. Of particular interest are individual differences in the temporal plasticity of personality traits over extended (ontogenetic) periods of time, because of the relevance of these data to models of behavioral development. We discuss recent empirical studies of the temporal consistency of personality over ontogeny, and models that make contrasting predictions about individual differences in the developmental trajectories of behavioral traits. In addition, we consider recent advances in studies of relationships between personality traits and particular types of behavioral plasticity, including statistical methods which facilitate analyses of relationships between personality traits, contextual plasticity, temporal plasticity and intraindividual variability, and empirical tests of predicted relationships between personality traits and other types of behavioral plasticity (flexibility, learning rates). As the field of animal personality and behavioral plasticity moves from a largely descriptive to a predictive phase, we suggest that there is ample room for empirical tests of recent models that predict individual differences in behavioral developmental trajectories, and for the development of new formal models that make strong predictions about relationships between personality traits and specific types of behavioral plasticity.

Personality and plasticity: consistent responses within-, but not across-temperature situations in crabs

Recent research suggests that repeated assays of behaviour, conducted both within and across situations, could reveal important insights into two traditionally distinct areas of study: animal personality and individual differences in behavioural plasticity. However, at present relatively few studies present such data, and few consider how changing abiotic conditions affect behavioural plasticity. Individual differences in metabolic rate have been suggested as a proximate mechanism promoting personality, leading one to speculate that individual differences in metabolic sensitivity to temperature may affect behavioural responses in ectotherms. At present, only one study (out of two) has tested for and shown individual differences in behavioural responses to temperature. Here, we repeatedly assayed the behaviour of a marine crab across a narrow range of temperatures to test for individual differences in responses to temperature. We observed large inter-individual differences in behaviour that were consistent over time at a given temperature (evidence for personality), and individual differences in responses to temperature (evidence for plasticity). This study adds to the very scant literature on ectotherm behavioural sensitivity to temperature, and suggests the phenomenon might be widespread. We speculate about the role of metabolism as a proximate mechanism that might explain these individual differences in plasticity and make suggestions for future research to test this hypothesis. © Koninklijke Brill NV, Leiden, The Netherlands.

Early-developmental stress, repeatability, and canalization in a suite of physiological and behavioral traits in female zebra finches

Adaptive developmental plasticity allows individuals experiencing poor environmental conditions in early life to adjust their life-history strategy in order to prioritize short-term fitness benefits and maximize reproductive output in challenging environments. Much research has been conducted to test whether such adoption of a "faster" life-history strategy is accompanied by concordant changes in behavior and physiology, with mixed results. As research in this field has focused on comparison of mean-level responses of treatment groups, few studies include repeated measures of response variables and the effect that developmental stress may have on repeatability per se. We investigated how early-developmental stress affects the mean expression of (and repeatability in) a variety of behavioral and physiological traits in female zebra finches. We predicted that: (1) individuals subjected to nutritional restriction in the nestling phase would have higher feeding and activity rates, with associated increases in hematocrit and basal metabolic rates (BMRs), (2) nutritional restriction in early life would alter adults' stress-induced corticosterone level, and (3) developmental stress would, respectively, influence the amount of among-individual and within-individual variation in behavioral and physiological traits, hence affecting the repeatability of these traits. In comparison to control females, stressed females did not differ in activity rate or stress-induced corticosterone level, but they did have higher levels of feeding, hematocrit, and BMR. Among-individual variance and repeatability were generally higher in stressed females than in controls. Finally, we found that developmental dietary restriction significantly reduced the amount of within-individual variance both in activity rate in the novel environment and in stress-induced corticosterone level. Our results not only confirm previous findings on the effect of early-developmental stress on BMR, but also extend its effect to feeding rate and hematocrit, suggesting that developmental plasticity in these traits is ontogenetically linked. Early-developmental stress may disable particular genetic canalizing processes, which would release cryptic genetic variation and explain why repeatability and among-individual variance were generally higher in the stressed groups than in controls. For activity rate in the novel environment and with stress-induced corticosterone level, however, early-developmental stress significantly reduced within-individual variance, which may be a consequence of increased canalization of these traits at the micro-environmental level.

Behavioral versus demographic predictors of early adoption : a critical analysis and comparative test

Predicting which consumers will be amongst the first to adopt an innovative product is a difficult task but is valuable in allowing effective and efficient use of marketing resources. This paper examines the accuracy of predictions made about likely first adopters based on the most widely accepted theory and compares them to predictions made by examining the relevant past behavior of consumers. A survey of over 1000 consumers examined adoption of an innovative technology: compact fluorescent lightglobes. The results show that variables which were derived from a utility and awareness perspective were a more accurate and managerially useful predictor than the demographic variables derived from the widely accepted theory based on the work of Rogers. It is suggested that these alternative variables could be utilized more readily by marketing managers in many circumstances.

Effect of deformation schedule on the microstructure and mechanical properties of a thermomechanically processed C-Mn-Si transformation-induced plasticity steel

Thermomechanical processing simulations were performed using a hot-torsion machine, in order to develop a comprehensive understanding of the effect of severe deformation in the recrystallized and nonrecrystallized austenite regions on the microstructural evolution and mechanical properties of the 0.2 wt pct C-1.55 wt pct Mn-1.5 wt pct Si transformation-induced plasticity (TRIP) steel. The deformation schedule affected all constituents (polygonal ferrite, bainite in different morphologies, retained austenite, and martensite) of the multiphased TRIP steel microstructure. The complex relationships between the volume fraction of the retained austenite, the morphology and distribution of all phases present in the microstructure, and the mechanical properties of TRIP steel were revealed. The bainite morphology had a more pronounced effect on the mechanical behavior than the refinement of the microstructure. The improvement of the mechanical properties of TRIP steel was achieved by variation of the volume fraction of the retained austenite rather than the overall refinement of the microstructure.

Effect of microstructure on the stability of retained austenite in transformation-induced-plasticity steels

Two Fe-0.2C-1.55Mn-1.5Si (in wt pet) steels, with and without the addition of 0.039Nb (in wt pet), were studied using laboratory rolling-mill simulations of controlled thermomechanical processing. The microstructures of all samples were characterized by optical metallography, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The microstructural behavior of phases under applied strain was studied using a heat-tinting technique. Despite the similarity in the microstructures of the two steels (equal amounts of polygonal ferrite, carbide-free bainite, and retained austenite), the mechanical properties were different. The mechanical properties of these transformation-induced-plasticity (TRIP) steels depended not only on the individual behavior of all these phases, but also on the interaction between the phases during deformation. The polygonal ferrite and bainite of the C-Mn-Si steel contributed to the elongation more than these phases in the C-Mn-Si-Nb-steel. The stability of retained austenite depends on its location within the microstructure, the morphology of the bainite, and its interaction with other phases during straining. Granular bainite was the bainite morphology that provided the optimum stability of the retained austenite.

Behavioral characteristics of men accused of rape: evidence for different types of rapists

The aim of this study was to determine whether the behavioral characteristics demonstrated by rapists clustered together into groups that were similar to the common rapist typology in the literature: anger, power exploitative, power reassurance, and sadistic. Two studies were conducted to examine the evidence for this typology. Study 1 involved the analysis of data from 130 men charged with sexual assault and Study 2 involved the analysis of court transcripts from 50 rape cases tried through the court system. The results of Study 1 revealed that there was some validity to the characteristics usually associated with each of the four types of rape, especially for the power reassurance and sadistic rapists. However, there were some unexpected outliers within both the anger and power exploitative types of rapists, which may suggest that there is more than one type of anger rapist and more than two types of power rapists. The results of Study 2 very closely replicated the results of Study 1. Future research needs to focus on the behavioral, motivational, and cognitive characteristics associated with each of the types of rapists and research them separately, so that it is possible to further evaluate the evidence for the typology identified in this study.

Behavioral adaptation within cross-cultural virtual teams

With today's business environments no longer confined to national borders, much work is undertaken in global virtual teams. Such teams consist of members located in different countries that communicate via technology media to complete a project task. Much of the research in this area has been focused on the technological aspects of such environments; there is, however, a lack of research into the behavioral aspects and the issue of cultural differences in particular. It has been acknowledged that when cultural diversity is neither recognized nor acted upon, significant challenges can arise for the team. Current advice in the literature suggests that team members should adapt their normal working behavior in consideration of cultural differences. However, there is little indication of how team members should do so. This study investigated if and/or how team members adapt their behavior in cross-cultural virtual teams. The results of this study indicate that team members can adapt their behavior in both spoken and written communication as well as allowing for religious beliefs and time zone differences. This paper discusses specifically how behavior can be adapted, including a discussion of behaviors that caused concern. Finally, a framework of behavioral adaptations is presented for ways to improve cross-cultural virtual team interactions.

The plasticity of professional boundaries: a case study of collaborative care in maternity services

A case study of twenty-nine midwives and nine obstetricians working in a regional, public sector Australian hospital demonstrates the plasticity of professional boundaries within a post-welfare state. Driven by new discourses of globalisation, marketisation, managerialism and consumerism, professional boundaries in health care are being blurred, reordered and reconstituted. Government policies that call for a new interdisciplinarity between maternity professionals may be seen as responses to the above pressures. However, there remain considerable barriers to achieving collaborative models including conflicting interpretations of risk, of women's bodies and of childbirth; the veto power of decision-making retained by obstetricians; questions of professional accountability; and diversity over appropriate styles of micro-interaction. Collaboration demands a new egalitarianism to eclipse the old vertical system of obstetric dominance and this means that midwives need to create a distinctive professional specialty, or new object of knowledge. Midwives' skill in 'emotion management' could provide this speciality in addition to their rational-technical knowledge and thus elevate midwifery to an equivalent professional status with obstetrics but as yet neither obstetrics nor midwifery have realised its professionalising potential

Testing the factor structure of the behavioral-intentions battery: an empirical study of the Australian banking industry

The five-factor ‘Behavioural-Intentions Battery’ was developed by Zeithaml, Berry and Parasuraman (1996), to measure customer behavioural and attitudinal intentions. The structure of this model was re-examined by Bloomer, de Ruyter and Wetzels (1999) across different service industries. They concluded that service loyalty is a multi dimensional construct consisting of four, not five, distinct dimensions. To date, neither model has been tested within a banking environment. This research independently tested the ‘goodness of fit’ of both the four and five-factor models, to data collected from branch bank customers. Data were collected via questionnaire with a sample of 348 banking customers. A confirmatory factor analysis was conducted upon the two opposing factor structures, revealing that the five-factor structure has a superior model fit; however, the fit is ‘marginal’.

Drop out from behavioral management training programs for ADHD: a prospective study

To investigate dropout from parenting programs for disruptive behavior disorders, we followed 18 clients prospectively from the beginning of a manualized treatment program to three month follow-up. Using qualitative and quantitative methods, we then compared those who dropped out of the program with those who completed it. We found that in general, those participants who dropped out of the program were parents of children with more disturbed behavior, who perceived their children to be more difficult than others, and who experienced more subjective parenting stress. Those who dropped out were also not convinced that the strategies proposed in the program to help manage their children were useful. On the other hand, those who completed the program reported a determination to persevere with the strategies which they saw as assisting them to re-establish positive relationships with their adolescent children. The findings are discussed in the context of how manualized programs might be modified to increase retention.

Transmission electron microscopy characterization of the bake-hardening behavior of transformation-induced plasticity and dual-phase steels

The effect of prestraining (PS) and bake hardening (BH) on the microstructures and mechanical properties has been studied in transformation-induced plasticity (TRIP) and dual-phase (DP) steels after intercritical annealing. The DP steel showed an increase in the yield strength and the appearance of the upper and lower yield points after a single BH treatment as compared with the as-received condition, whereas the mechanical properties of the TRIP steel remained unchanged. This difference appears to be because of the formation of plastic deformation zones with high dislocation density around the “as-quenched” martensite in the DP steel, which allowed carbon to pin these dislocations, which, in turn, increased the yield strength. It was found for both steels that the BH behavior depends on the dislocation rearrangement in ferrite with the formation of cell, microbands, and shear band structures after PS. The strain-induced transformation of retained austenite to martensite in the TRIP steel contributes to the formation of a complex dislocation structure.

An individualized psychosocial approach for "treatment resistant" behavioral symptoms of dementia among aged care residents

Background: Behavioral symptoms of dementia are common among residents in mainstream aged care settings, and have a substantial impact on residents and professional caregivers. This study evaluated the impact of individualized psychosocial interventions for behavioral symptoms through a small preliminary study.
Method: Interventions were delivered to a patient group of 31 psychogeriatric aged care residents who presented with behavioral symptoms of dementia that had failed to respond to pharmacological treatment approaches. Outcome data on severity of behaviors, health service utilization and staff burden of care were collected.
Results: A modest but significant reduction in staff ratings of the severity of aggressive and verbally agitated behavioral symptoms was found, with an associated reduction in their perceptions of the burden of caring for these patients. Reduced behavioral disturbance was associated with a reduction in the requirement for primary care consultations, and all participants were able to continue to reside in mainstream aged care facilities, despite an increase in the severity of dementia.
Conclusions: This study supported the use of individualized psychological strategies for behavioral symptoms at all stages of dementia. Methodological limitations of this preliminary study are discussed.

Effectiveness of staff training programs for behavioral problems among older people with dementia

This paper reviewed studies on staff training programs to address the behavioral problems associated with dementia among older people in residential care. The papers were classified according to whether or not the studies included a control group in the research design. The results of the review demonstrate that there has been a wide range of psychosocial and educational interventions to reduce behavioral problems among older people with dementia, with inconsistent results being obtained. However, many of these studies suffer from problems in their research design that make it difficult to evaluate their effectiveness. Problems in conducting research in the nursing home setting are highlighted, and suggestions for future research in this area are discussed.