857 resultados para INDIVIDUAL-DIFFERENCES


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Background Considerable evidence from twin and adoption studies indicates that genetic and shared environmental factors play a significant role in the initiation of smoking behavior. Although twin and adoption designs are powerful to detect genetic and environmental influences, they do not provide information on the processes of assortative mating and parent–offspring transmission and their contribution to the variability explained by genetic and/or environmental factors. Methods We examined the role of genetic and environmental factors for smoking initiation using an extended kinship design. This design allows the simultaneous testing of additive and non-additive genetic, shared and individual-specific environmental factors, as well as sex differences in the expression of genes and environment in the presence of assortative mating and combined genetic and cultural transmission. A dichotomous lifetime smoking measure was obtained from twins and relatives in the Virginia 30,000 sample. Results Results demonstrate that both genetic and environmental factors play a significant role in the liability to smoking initiation. Major influences on individual differences appeared to be additive genetic and unique environmental effects, with smaller contributions from assortative mating, shared sibling environment, twin environment, cultural transmission and resulting genotype–environment covariance. The finding of negative cultural transmission without dominance led us to investigate more closely two possible mechanisms for the lower parent–offspring correlations compared to the sibling and DZ twin correlations in subsets of the data: (i) age × gene interaction, and (ii) social homogamy. Neither mechanism provided a significantly better explanation of the data, although age regression was significant. Conclusions This study showed significant heritability, partly due to assortment, and significant effects of primarily non-parental shared environment on smoking initiation.

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An experiment was conducted to investigate the idea that an important motive for identifying with social groups is to reduce subjective uncertainty, particularly uncertainty on subjectively important dimensions that have implications for the self-concept (e.g., Hogg, 1996; Hogg & Mullin, 1999). When people are uncertain on a dimension that is subjectively important, they self-categorize in terms of an available social categorization and, thus, exhibit group behaviors. To test this general hypothesis, group membership, task uncertainty, and task importance were manipulated in a 2 x 2 x 2 between-participants design (N = 128), under relatively minimal group conditions. Ingroup identification and desire for consensual validation of specific attitudes were the key dependent measures, but we also measured social awareness. All three predictions were supported. Participants identified with their group (H1), and desired to obtain consensual validation from ingroup members (H2) when they were uncertain about their judgments on important dimensions, indicating that uncertainty reduction motivated participants towards embracing group membership. In addition, identification mediated the interactive effect of the independent variables on consensual validation (H3), and the experimental results were not associated with an increased sense of social awareness and, therefore, were unlikely to represent only behavioral compliance with generic social norms. Some implications of this research in the study of cults and totalist groups and the explication of genocide and group violence are discussed.

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The current study aimed to investigate and provide furthering evidence of individual differences as determinants of task performance. This research focused on the effects of the personality traits Openness to Experience and Neuroticism, and two goal orientation traits. Learning Orientation and Avoid Orientation, on task performance. The hypotheses addressed the predictability of the traits, the differential effects of personality and goal orientation traits, and the mediating effects of goal orientation on the relationship between personality and performance. The results were based on questionnaire responses completed by a sample of 103 students. Scores on a computerised Air Traffic Control (ATC) decision-making task were used as a measure of task performance. Learning Orientation was found to be a significant predictor of performance, whilst the effect of Neuroticism was 'approaching' significance. Results indicated strong support for the differential relationship between personality traits and corresponding goal orientation traits. The mediating relationship between Openness to Experience, Learning Orientation and performance was also found to be 'approaching' significance. Results were indicative of the influences of personality and goal orientation on consequent performance outcomes. Implications were discussed, as well as suggestions for possible future directions in research assessing the predictabilit)' of individual differences in learning contexts.

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Despite institutional commitment to diversity initiatives (e.g., affirmative action), employees often harbour negative attitudes towards such initiatives and their beneficiaries. Dispositional variables (e.g., neo-sexism), have often been implicated in these negative reactions. We reason that more immediate group-based beliefs (e.g., subjective beliefs about the intergroup context), also shape attitudinal and behavioural reactions and that individual and group-based beliefs are rationalised through appeals to justice and fairness concerns. In this study using early career academics we examined the role of individual differences and socio-structural beliefs (about the stability, legitimacy and permeability of the intergroup situation), to feelings of relative deprivation, perceived justice and attitudes towards gender equity initiatives. Results provided support for the role of group-based beliefs and for the mediating role of justice concerns.

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Using magnetoencephalography, we studied the spatiotemporal properties of cortical responses in terms of event-related synchronization and event-related desynchronization to a range of stripe patterns in subjects with no neurological disorders. These stripes are known for their tendency to induce a range of abnormal sensations, such as illusions, nausea, dizziness, headache and attacks of pattern-sensitive epilepsy. The optimal stimulus must have specific physical properties, and maximum abnormalities occur at specific spatial frequency and contrast. Despite individual differences in the severity of discomfort experienced, psychophysical studies have shown that most observers experience some degree of visual anomaly on viewing such patterns. In a separate experiment, subjects reported the incidence of illusions and discomfort to each pattern. We found maximal cortical power in the gamma range (30-60 Hz) confined to the region of the primary visual cortex in response to patterns of 2-4 cycles per degree, peaking at 3 cycles per degree. This coincides with the peak of mean illusions and discomfort, also maximal for patterns of 2-4 cycles per degree. We show that gamma band activity in V1 is a narrow band function of spatial frequency. We hypothesize that the intrinsic properties of gamma oscillations may underlie visual discomfort and play a role in the onset of seizures.

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When our two eyes view incompatible images, the brain invokes suppressive processes to inhibit one image, and favor the other. Two phenomena are typically observed: dichoptic masking (reduced sensitivity to one image) for brief presentations, and binocular rivalry (alternation between the two images), over longer exposures. However, it is not clear if these two phenomena arise from a common suppressive process. We investigated this by measuring both threshold elevation in simultaneous dichoptic masking and mean percept durations in rivalry, whilst varying relative stimulus orientation. Masking and rivalry showed significant correlations, such that strong masking was associated with long dominance durations. A second experiment suggested that individual differences across both measures are also correlated. These findings are consistent with varying the magnitude of interocular suppression in computational models of both rivalry and masking, and imply the existence of a common suppressive process. Since dichoptic masking has been localised to the monocular neurons of V1, this is a plausible first stage of binocular rivalry.

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Three hypotheses have been proposed to explain neuropathological heterogeneity in Alzheimer's disease (AD): the presence of distinct subtypes ('subtype hypothesis'), variation in the stage of the disease ('phase hypothesis') and variation in the origin and progression of the disease ('compensation hypothesis'). To test these hypotheses, variation in the distribution and severity of senile plaques (SP) and neurofibrillary tangles (NFT) was studied in 80 cases of AD using principal components analysis (PCA). Principal components analysis using the cases as variables (Q-type analysis) suggested that individual differences between patients were continuously distributed rather than the cases being clustered into distinct subtypes. In addition, PCA using the abundances of SP and NFT as variables (R-type analysis) suggested that variations in the presence and abundance of lesions in the frontal and occipital lobes, the cingulate gyrus and the posterior parahippocampal gyrus were the most important sources of heterogeneity consistent with the presence of different stages of the disease. In addition, in a subgroup of patients, individual differences were related to apolipoprotein E (ApoE) genotype, the presence and severity of SP in the frontal and occipital cortex being significantly increased in patients expressing apolipoprotein (Apo)E allele ε4. It was concluded that some of the neuropathological heterogeneity in our AD cases may be consistent with the 'phase hypothesis'. A major factor determining this variation in late-onset cases was ApoE genotype with accelerated rates of spread of the pathology in patients expressing allele ε4.

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This study examined the influence of organizational justice perceptions on employee work outcome relationships as moderated by individual differences that are influenced by societal culture. Power distance, but not country or individualism, moderated the relationships between perceived justice and satisfaction, performance, and absenteeism. The effects of perceived justice on these outcomes were stronger among individuals scoring lower on power distance index, and most of these study participants were in the U.S. (versus Hong Kong) sample. Limitations of the study and the implications of the findings for managing cross-culturally are discussed.

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Uncertified absence from work has traditionally been difficult to link to personality. The present paper argues that personality is best conceptualized as influencing an individual’s intention to be absent from work because of reasons that are within their control. This was investigated in an employed community sample of 128 individuals. These individuals used a self-report measure to express their future intentions to be absent from work as a result of several reasons. These reasons for absence were categorized as “being absent because of external pressure or commitment” (ABCo) and “being absence by choice” (ABCh). The Big Five personality factors were found to be unrelated to objective uncertified absence records and unrelated to ABCo. Three of the Big Five were related to ABCh. Agreeableness was negatively related to ABCh whereas Extraversion and Openness demonstrated a positive correlation. It was concluded that the results should be viewed tentatively, but that this study may provide a useful framework for conceptualizing the association of personality with uncertified absence.

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Research into social facilitation effects reveals three factors affecting response performance: types of task, types of audience and type of actor. This study attempts to establish a minimal baseline for task and audience type in order to examine difference between personality types in the actors. Results indicate that performance in both extraverts and introverts increases in the minimal conditions of the mere presence of another person whilst carrying out a simple mathematical task. These results are interpreted through an analysis of Zajonc's (1965) drive theory with Eysenck's (1967) personality theory indicating that through further investigation performance curves might be devised for introverts and extraverts performing under a variety of task and audience conditions.

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John Bowlby's use of evolutionary theory as a cornerstone of his attachment theory was innovative in its day and remains useful. Del Giudice's target article extends Belsky et al.'s and Chisholm's efforts to integrate attachment theory with more current thinking about evolution, ecology, and neuroscience. His analysis would be strengthened by (1) using computer simulation to clarify and simulate the effects of early environmental stress, (2) incorporating information about non-stress related sources of individual differences, (3) considering the possibility of adaptive behavior without specific evolutionary adaptations, and (4) considering whether the attachment construct is critical to his analysis.

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During the early stages of employment, newly hired employees find out what their new organisations are like. Their first impressions are extremely important in determining the course of subsequent attitudes and behaviour. Recently, a considerable progress has been made towards the understanding of adjustment process, however, the literature remain divided along a number of fronts. Moreover, newcomer research has been conducted independent and irrespective of newcomer personality individual differences. This seems to be a critical oversight because there is overlap in predictions involving these constructs. The current research extended the previous one by examining these multiple antecedents, including Big Five personality traits of newcomer to the tandem process of adjustment as well as outcomes that immediate, or ?proximal? to the process of newcomer adjustment. Following a cross sectional pilot study of recent college graduate, a three- wave longitudinal study of newcomers in seven organisations examined Big Five personality traits, proactive behaviour, and socialisation influence (formal training, leaders, co-workers) as antecedents of proximal adjustment outcomes (group integration, political knowledge of organisation, and task performance). The main study results suggested that personality traits were related to proximal adjustment outcomes, specifically, Conscientiousness was positively related to all proximal adjustment outcomes. Openness to experience was related to task performance and political knowledge. Group integration is independently related to Agreeableness, Extraversion and Neuroticism. The socialisation influence moderate these relations, for example, leader socialisation moderate Conscientiousness as it relates to political knowledge and group integration, while co-worker moderate Extraversion as it relates to task performance. Finally, it was found that, the relationship between proximal adjustment outcomes and the personality dimensions Openness was mediated by proactive behaviour. Overall, the results suggested that individual differences have a role in newcomer adjustment as it facilitate the socialisation influence, and Big Five was one of the key determinants of newcomer adjustment.

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Investigations of relationships between the specific personality variable, locus of control (LOC, Rotter, 1966) and driver behaviour or accidents have returned contrasting results. Review suggests dependence on gender or experience characteristics of participants, suggesting these factors interact with LOC to influence driving. Relationships were investigated in terms of influence on the eight driving styles of the Multidimensional Driving Style Inventory (MDSI, Taubman-Ben-Ari, Mikulincer & Gillarth, 2004) in young drivers (18-29 years). Gender and LOC differences in driving styles previously related to accidents were proposed. It was also proposed that driving experience influences driving style, and LOC influences effect of driving experience. Gender differences were found for dissociative, anxious, patient, risky, angry and high velocity styles. Women had more external LOC than men, and driver stress styles increased with more external LOC, but reduced with increased driving experience, but so did patient style. High velocity style increased with experience. Controlling for LOC revealed important gender differences in effect of experience: positive effects for men (reducing angry and high velocity, increasing carefulness) and negative effects for women (increasing angry and higher velocity, reducing carefulness). Findings suggest negative influence of high internal LOC on young men in terms of its interaction with experience.

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There has been a recent explosion of interest in Lesbian, Gay, Bisexual and Trans Perspective Psychology amongst students and academics, and this interest is predicted to continue to rise. Recent media debates on subjects such as same–sex marriage have fuelled interest in LGBTQ perspectives. This edited collection showcases the latest thinking in LGBTQ psychology. The book has 21 chapters covering subjects such as same sex parenting, outing, young LGBTQ people, sport, learning disabilities, lesbian and gay identities etc. The book has an international focus, with contributors from UK, US, Canada, Australia and New Zealand List of Contributors. Foreword by Jerry J. Bigner. 1. Introducing Out in Psychology (Victoria Clarke and Elizabeth Peel). 2. From lesbian and gay psychology to LGBTQ psychologies: A journey into the unknown (Victoria Clarke and Elizabeth Peel) 3. What comes after discourse analysis for LGBTQ psychology(Peter Hegarty). 4. Recognising race in LGBTQ psychology: Power, privilege and complicity (Damien W. Riggs). 5. Personality, individual differences and LGB psychology (Gareth Hagger Johnson). 6. Heteronormativity and the exclusion of bisexuality in psychology (Meg Barker). 7. A minority within a minority: Experiences of gay men with intellectual disabilities.(Christopher Bennett and Adrian Coyle). 8. Closet talk: The contemporary relevance of the closet in lesbian and gay interaction (Victoria Land and Celia Kitzinger) 9. Romance, rights, recognition, responsibilities and radicalism: Same-sex couples’ accounts of civil partnership and marriage (Victoria Clarke, Carole Burgoyne and Maree Burns). 10. The experience of social power in the lives of trans people (Clair Clifford and Jim Orford). 11. What do they look like and are they among us? Bisexuality, (dis.closure and (Maria Gurevich, Jo Bower, Cynthia M. Mathieson and Bramilee Dhayanandhan). 12. Heterosexism at work: Diversity training, discrimination law and the limits of liberal individualism (Rosie Harding and Elizabeth Peel). 13. Out on the ball fields: Lesbians in sport (Vikki Krane and Kerrie J. Kauer). 14. Homophobia, rights and community: Contemporary issues in the lives of LGB people in the UK (Sonja J. Ellis). 15. Striving for holistic success: How lesbians come out on top (Faith Rostad and Bonita C. Long). 16. On Passing: The Interactional Organization of Appearance Attributions in the Psychiatric Assessment of Transsexual Patients (Susan A. Speer and Richard Green). 17. Alcohol and gay men: Consumption, promotion and policy responses (Jeffrey Adams, Timothy McCreanor and Virginia Braun). 18. Towards a clinical-psychological approach to address the hetero sexual concerns of intersexed women (Lih-Mei Liao). 19. Educational psychology practice with LGB youth in schools: Individual and institutional interventions (Jeremy J. Monsen and Sydney Bailey). 20. Que(e)rying the meaning of lesbian health: Individual(izing and community discourses (Sara MacBride-Stewart). 21. Transsexualism: Diagnostic dilemmas, transgender politics and the future of transgender care (Katherine Johnson). Index.

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This study examined the extent to which students could fake responses on personality and approaches to studying questionnaires, and the effects of such responding on the validity of non-cognitive measures for predicting academic performance (AP). University students produced a profile of an ‘ideal’ student using the Big-Five personality taxonomy, which yielded a stereotype with low scores for Neuroticism, and high scores for the other four traits. A sub-set of participants were allocated to a condition in which they were instructed to fake their responses as University applicants, portraying themselves as positively as possible. Scores for these participants revealed higher scores than those in a control condition on measures of deep and strategic approaches to studying, but lower scores on the surface approach variable. Conscientiousness was a significant predictor of AP in both groups, but the predictive effect of approaches to studying variables and Openness to Experience identified in the control group was lower in the group who faked their responses. Non-cognitive psychometric measures can be valid predictors of AP, but scores on these measures can be affected by instructional set. Further implications for psychometric measurement in educational settings are discussed.