Helping people to sort it out: The role of social support in the Job Strain Model

This paper reports three studies of occupational stress investigating the role of social support as an intervening variable in the Job Strain Model (Karasek, 1979). A computer simulated mail-sorting work environment was used to assess the effect of demands, control and social support on measures of strain, satisfaction, and perceived and actual task performance. The first experiment ( N =60) tests the basic Job Strain Model by manipulating levels of task demand and control. The second experiment ( N =120) compares high and low levels of two types of social support (informational support and emotional support) to determine whether and how they interact with extreme conditions of the Job Strain Model (high strain and low strain). The final experiment ( N =90) investigates positive and negative forms of social support (praise and criticism) in relation to extreme job strain conditions. Results show that the job strain model is consistent with the stress and performance data, although stress showed no Demand ×Control interaction. Social supports increased arousal, satisfaction and perceived performance, but did not affect stress or task performance. Moreover, contrary to buffer theories, social supports did not interact with the job strain variables. Congruence between preferred and experienced emotional support levels also predicted performance.     

Helping people to sort it out: The role of social support in the Job Strain Model

This paper reports three studies of occupational stress investigating the role of social support as an intervening variable in the Job Strain Model (Karasek, 1979). A computer simulated mail-sorting work environment was used to assess the effect of demands, control and social support on measures of strain, satisfaction, and perceived and actual task performance. The first experiment ( N =60) tests the basic Job Strain Model by manipulating levels of task demand and control. The second experiment ( N =120) compares high and low levels of two types of social support (informational support and emotional support) to determine whether and how they interact with extreme conditions of the Job Strain Model (high strain and low strain). The final experiment ( N =90) investigates positive and negative forms of social support (praise and criticism) in relation to extreme job strain conditions. Results show that the job strain model is consistent with the stress and performance data, although stress showed no Demand 2 Control interaction. Social supports increased arousal, satisfaction and perceived performance, but did not affect stress or task performance. Moreover, contrary to buffer theories, social supports did not interact with the job strain variables. Congruence between preferred and experienced emotional support levels also predicted performance.     

The moderating role of social support in Karasek's job strain model

This paper examines whether social support is a boundary-determining criterion in the job strain model of Karasek (1979). The particular focus is the extent to which different sources of social support, work overload and task control influence job satisfaction, depersonalization and supervisor assessments of work performance. Hypotheses are tested using prospective survey data from 80 clerical staff in a university setting. Results revealed 3-way interactions among levels of support (supervisor, co-worker, non-work), perceived task control and work overload on levels of work performance and employee adjustment (self-report). After controlling for levels of negative affect in all analyses, there was evidence that high levels of supervisor support mitigated against the negative effects of high strain jobs on levels of job satisfaction and reduced reported levels of depersonalization. Moreover, high levels of non-work support and co-worker support also mitigated against the negative effects of high strain jobs on levels of work performance. The results are discussed in terms of the importance of social support networks both at, and beyond, the work context.     

The Demands-Control-Support model,locus of control and job dissatisfaction: A longitudinal study

The Job-Demands-Control model (Karasek, 1979) has been widely studied in the job stress field, but the results obtained are frequently contradictory. Therefore, some investigations have expanded the model by including social support and personality characteristics such as locus of control. However, results obtained with these elaborated models have not been conclusive either. The present study sets out to integrate both types of expansions by simultaneously including social support at work and the employee's locus of control in a longitudinal multi-national study among 542 administrative personnel from Belgium, England, Spain, Italy and Israel. Hierarchical moderated multiple regression showed a significant 4-way interaction term (Demands 2 Control 2 Social support 2 Locus of control) on the change in job dissatisfaction. This effect is qualified by the interaction between job demands and control only for an internal locus of control with high social support. Contrary to the prediction of the JDC model, which posits that high control has a buffering effect on job dissatisfaction, the study result indicates a damaging effect of excess control (perceived job control and high internal locus of control), specifically in high social support situations.     

The effects of new dimensions of psychological job demands and job control on active learning and occupational health

Recent changes in job content may have led to changes in job demands and control, and earlier operationalizations of the demand concept may be too general (MT). The aim of this paper is to show how new dimensions of psychological job demands are related to two sets of outcome variables, employee health and active learning, and how these relationships are modified or interact with social support and types of job control. The study was carried out as a survey among employees of 13 electric companies in Norway, N=2435. Lisrel was used to assess the fit of the proposed models. Compared to the traditional demands control model, an extended version used in this study increased the explained variance on an average by 4% on various occupational health variables. It was found that various dimensions of demands were differentially related to the outcome variables. Skill discretion uniformly reduced the effect of the demands: for groups low in skill discretion there was a stronger relationship between demands and outcomes than for groups high in skill discretion. The interaction pattern for the remaining control and support variables was however more complicated and warrants further study. The practical implications are that employers should carefully consider the quality of work. Special attention should be given to the quantitative demands of the jobs, since there seems to be few moderators for the relationship between those demands and job stress and subjective health complaints.     

The Demands-Control-Support model, locus of control and job dissatisfaction: a longitudinal study

The Job-Demands-Control model (Karasek, 1979) has been widely studied in the job stress field, but the results obtained are frequently contradictory. Therefore, some investigations have expanded the model by including social support and personality characteristics such as locus of control. However, results obtained with these elaborated models have not been conclusive either. The present study sets out to integrate both types of expansions by simultaneously including social support at work and the employee's locus of control in a longitudinal multi-national study among 542 administrative personnel from Belgium, England, Spain, Italy and Israel. Hierarchical moderated multiple regression showed a significant 4-way interaction term (Demands ×Control ×Social support ×Locus of control) on the change in job dissatisfaction. This effect is qualified by the interaction between job demands and control only for an internal locus of control with high social support. Contrary to the prediction of the JDC model, which posits that high control has a buffering effect on job dissatisfaction, the study result indicates a damaging effect of excess control (perceived job control and high internal locus of control), specifically in high social support situations.     

The association between job skill discretion,decision authority and burnout

This paper reports on the relationship between dimensions of control (skill discretion and decision authority) and burnout (emotional exhaustion, depersonalization, and reduced personal accomplishment) among 164 human service workers. It examines the differential influence of job demands, control (skill discretion and decision authority) and social support (supervisor, co-workers, others) on each burnout dimension. Then it examines the moderating effects of higher skill discretion, higher decision authority, and higher social support on burnout. Low skill discretion was found to be associated with high emotional exhaustion and depersonalization and low personal accomplishment. The effects of decision authority were not statistically significant. High job demands were associated with high emotional exhaustion only. Social support (supervisor, co-worker, and others) was not associated with burnout when demographic variables and job characteristics were controlled for. Neither dimension of control moderated the impact of high job demands on burnout. Social support did not moderate the impact of high demands, low skill discretion, or low decision authority on any burnout dimension. The full model explained 44% of the variance in emotional exhaustion, 25% in depersonalization, and 42% in personal accomplishment. Despite its limitations, the study suggests that the Job Demand-Control model may provide a useful theoretical foundation for the study of burnout, but that the control dimensions need to be evaluated independently since they appear to be differentially related to the burnout dimensions.     

The effects of new dimensions of psychological job demands and job control on active learning and occupational health

Abstract

Recent changes in job content may have led to changes in job demands and control, and earlier operationalizations of the demand concept may be too general (MT). The aim of this paper is to show how new dimensions of psychological job demands are related to two sets of outcome variables, employee health and active learning, and how these relationships are modified or interact with social support and types of job control. The study was carried out as a survey among employees of 13 electric companies in Norway, N=2435. Lisrel was used to assess the fit of the proposed models. Compared to the traditional demands control model, an extended version used in this study increased the explained variance on an average by 4% on various occupational health variables. It was found that various dimensions of demands were differentially related to the outcome variables. Skill discretion uniformly reduced the effect of the demands: for groups low in skill discretion there was a stronger relationship between demands and outcomes than for groups high in skill discretion. The interaction pattern for the remaining control and support variables was however more complicated and warrants further study. The practical implications are that employers should carefully consider the quality of work. Special attention should be given to the quantitative demands of the jobs, since there seems to be few moderators for the relationship between those demands and job stress and subjective health complaints.     

Psychosocial work environment and mental health among travelling salespeople

Travelling salespeople have a rather unusual working environment, with long periods of absence from their firm and a low level of social contacts with colleagues. Furthermore, they are exposed to high demands in their work, which may conflict with a normal family life. In this paper a cross-sectional study of psychosocial work environment and mental health of Danish travelling salespeople is described. A sample of 1,306 travelling salespeople filled in a questionnaire (response rate 68%). The results indicate that poor mental health is associated with a number of demand indicators: number of working hours per week, number of customers per week, non-day work, and a high level of perceived job demands. On the other hand, the number of hours spent with customers per week is positively associated with mental health. The authors did not find the expected associations between poor mental health and several factors such as number of hours away from firm, nights away from home, and a low degree of perceived support from colleagues and superiors. It is concluded that the main stressors of travelling salespeople are long working hours, many customers, non-day work and high perceived psychological demands in general.     

Psychosocial work environment and mental health among travelling salespeople

Travelling salespeople have a rather unusual working environment, with long periods of absence from their firm and a low level of social contacts with colleagues. Furthermore, they are exposed to high demands in their work, which may conflict with a normal family life. In this paper a cross-sectional study of psychosocial work environment and mental health of Danish travelling salespeople is described. A sample of 1,306 travelling salespeople filled in a questionnaire (response rate 68%). The results indicate that poor mental health is associated with a number of demand indicators: number of working hours per week, number of customers per week, non-day work, and a high level of perceived job demands. On the other hand, the number of hours spent with customers per week is positively associated with mental health. The authors did not find the expected associations between poor mental health and several factors such as number of hours away from firm, nights away from home, and a low degree of perceived support from colleagues and superiors. It is concluded that the main stressors of travelling salespeople are long working hours, many customers, non-day work and high perceived psychological demands in general.     

The association between job skill discretion, decision authority and burnout

This paper reports on the relationship between dimensions of control (skill discretion and decision authority) and burnout (emotional exhaustion, depersonalization, and reduced personal accomplishment) among 164 human service workers. It examines the differential influence of job demands, control (skill discretion and decision authority) and social support (supervisor, co-workers, others) on each burnout dimension. Then it examines the moderating effects of higher skill discretion, higher decision authority, and higher social support on burnout. Low skill discretion was found to be associated with high emotional exhaustion and depersonalization and low personal accomplishment. The effects of decision authority were not statistically significant. High job demands were associated with high emotional exhaustion only. Social support (supervisor, co-worker, and others) was not associated with burnout when demographic variables and job characteristics were controlled for. Neither dimension of control moderated the impact of high job demands on burnout. Social support did not moderate the impact of high demands, low skill discretion, or low decision authority on any burnout dimension. The full model explained 44% of the variance in emotional exhaustion, 25% in depersonalization, and 42% in personal accomplishment. Despite its limitations, the study suggests that the Job Demand-Control model may provide a useful theoretical foundation for the study of burnout, but that the control dimensions need to be evaluated independently since they appear to be differentially related to the burnout dimensions.     

Human resource development,organization development,organizational learning,and organizational effectiveness: all needed more than ever

In this study the Job Demand-Control model was used to study the quality of working life of Dutch secondary teachers. The Job Demand-Control model of Karasek is a theoretical model in which stress and learning are both considered as dependent variables which are influenced by three different task characteristics: job demands, job control, and social support. This model was tested for Dutch secondary teachers (n = 542). Results shed light on the relationship between stress and learning, on the one hand, and the effects of task characteristics on work stress and on work-based learning, on the other hand. It is concluded that the relationship between stress and learning is mediated by the amount of job control as the model predicts. However, the results also reveal that the Karasek model is better suited for explaining stress than for explaining learning. To explain work-based learning variables other than task characteristics have to be taken into account.     

The Role of Social Support in Coping during the Anticipatory Stage of Organizational Change: A Test of an Integrative Model

Few researchers have explored how employees use social support to cope during organizational change. The current research proposed and tested a model that integrates moderation and mediation effects in order to understand how perceived available support influences employees' use of support mobilization to deal with change‐related stress. Survey data were collected from 476 health professionals working in a large public hospital undergoing large‐scale change and downsizing. Moderated path analyses revealed evidence to suggest that perceived available support plays a moderated mediation role during coping with change. Support mobilization mediated the indirect relationship between change‐related stress and job satisfaction, at both low and high levels of perceived available colleague support. Perceived available non‐work support moderated the relationship between support mobilization and job satisfaction, and perceived available supervisor support moderated the relationship between change‐related stress and support mobilization. The direction of simple effects was not always as expected and alternative explanations for these unexpected findings are offered, along with practical implications for supervisors managing organizational change.     

The effects of JDC model on burnout and work engagement: A multiple interaction analysis

This study investigated the moderating effects of functional social support (emotional and instrumental support) on the relationship of job demand control with burnout and work engagement. In total, 297 frontline employees from a hotpot restaurant franchise in China were surveyed. The results indicated emotional support, such as caring and inspiration, mitigated the adverse effects of high demand/low control on burnout and work engagement. Instrumental support, such as giving suggestions and solving problems, only mitigated the adverse effects of burnout. Further, the high demand/low control/low emotional support work condition was the most unfavourable for work engagement and burnout; while high demand/low control/low instrumental support was the most unfavourable condition for burnout. The theoretical and managerial implications of this research have been provided to gain a deeper insight into functional social support in the job demand control model.     

Interactive effects of perceived control and job stressors on affective reactions and health outcomes for clerical workers

Karasek's (1979) hypothesis that perceived control interacts with various job stressors in affecting employee satisfaction and health was tested. It was proposed that high levels of perceived stress would only be associated with poor health and negative affect in the presence of low control. One hundred and thirty-six clerical workers at a major US university completed questionnaries containing the measures of interest. The results of regression analyses failed to support the interaction hypothesis. However, measures related to both control and job stressors were found to correlate with satisfaction and health outcomes, as has been found in prior research. Limitations of the self-report and correlational methodology are discussed.     

The Job Demand-Control (-Support) Model and psychological well-being: A review of 20 years of empirical research

The Job Demand-Control (JDC) model (Karasek, 1979) and the Job Demand-Control-Support (JDCS) model (Johnson, and Hall, 1988) have dominated research on occupational stress in the last 20 years. This detailed narrative review focuses on the JDC(S) model in relation to psychological well-being. It covers research from 63 samples, published in the period 1979-1997. In the review a distinction is drawn between two different hypotheses prevailing in research on the models. According to the strain hypothesis of the JDC model, employees working in a high-strain job (high demands-low control) experience the lowest well-being. The buffer hypothesis states that control can moderate the negative effects of high demands on well-being. Translating these hypotheses to the expanded JDCS model, the iso-strain hypothesis predicts the most negative outcomes among workers in an iso-strain job (high demands-low control-low social support/isolation), whereas the buffer hypothesis states that social support can moderate the negative impact of high strain on well-being. Although the literature gives considerable support for the strain and iso-strain hypotheses, support for the moderating influence of job control and social support is less consistent. The conceptualization of demands and control is a key factor in discriminating supportive from nonsupportive studies. Only aspects of job control that correspond to the specific demands of a given job moderate the impact of high demands on well-being. Furthermore, certain subpopulations appear to be more vulnerable to high (iso)strain, whereas others benefit more from high control. On the basis of the results of this review, suggestions for future research and theoretical development are formulated.     

The Job Demand-Control (-Support) Model and psychological well-being: a review of 20 years of empirical research

The Job Demand-Control (JDC) model (Karasek, 1979) and the Job Demand-Control-Support (JDCS) model (Johnson, and Hall, 1988) have dominated research on occupational stress in the last 20 years. This detailed narrative review focuses on the JDC(S) model in relation to psychological well-being. It covers research from 63 samples, published in the period 1979-1997. In the review a distinction is drawn between two different hypotheses prevailing in research on the models. According to the strain hypothesis of the JDC model, employees working in a high-strain job (high demands-low control) experience the lowest well-being. The buffer hypothesis states that control can moderate the negative effects of high demands on well-being. Translating these hypotheses to the expanded JDCS model, the iso-strain hypothesis predicts the most negative outcomes among workers in an iso-strain job (high demands-low control-low social support/isolation), whereas the buffer hypothesis states that social support can moderate the negative impact of high strain on well-being. Although the literature gives considerable support for the strain and iso-strain hypotheses, support for the moderating influence of job control and social support is less consistent. The conceptualization of demands and control is a key factor in discriminating supportive from nonsupportive studies. Only aspects of job control that correspond to the specific demands of a given job moderate the impact of high demands on well-being. Furthermore, certain subpopulations appear to be more vulnerable to high (iso)strain, whereas others benefit more from high control. On the basis of the results of this review, suggestions for future research and theoretical development are formulated.     

Control, stress, and job satisfaction in Canadian nurses

The main effects of four domains of control (task, decision, resource, physical environment) on job satisfaction and their interactions with three types of job stressors (task demands, role conflict, interpersonal conflict) were examined in a sample of 765 Canadian nurses. Multiple regression analyses were conducted to determine the proportion of variance in job satisfaction that could be accounted for by job stressors, control, and the interaction of stressors and control in that order. The job stressors were analysed separately and as a composite job demands score, as were the four domains of control. The results indicated that the proportion of variance in job satisfaction increased with the addition of control for the composite scores and for task, resource, and physical environment control. However, decision control did not account for additional variance in job satisfaction above that for any of the job stressors. In addition, none of the stressor x control interactions were significant. The results support previous attempts to test the moderating effects of control, suggesting that perceived control is not a moderator of job stress but rather that it has a direct influence. The relevance of the different domains of control for nurses is discussed.     

Job design and levels of physical and mental strain among Australian prison officers

Over the past 15 years much has been made of the moderating influence of job discretion and support in occupations that are perceived to be high in demands. Such an effect seems to be most prevalent when subject populations are large and heterogeneous. One aim of this study was to examine the influence of subjective perceptions of these variables on strain reactions among a group of relatively homogeneous workers such as, in the present study, prison officers (n = 274). A second aim was to extend previous research and examine the joint influence of negative affectivity and perceptions of demands, discretion, and support on mental and physical well-being. It was hypothesized that those high in negative affect would be particularly strained by jobs perceived as being demanding. The hypothesized relationship between job demands, discretion and support were found to be weak and at times inconsistent. Social support, in particular, was found to have both positive and negative consequences for different aspects of well-being. Those high in negative affect were in general found to suffer lower mental well-being. More importantly, the interactive effect of negative affectivity and job demands was found to significantly predict the majority of the dependent variables used in this study. The valences of these relationships were inconsistent and are interpreted in light of Warr's (1987) vitamin model of stress.

There are several conclusions that can be drawn from the present study. Negative affectivity appears to have a truly interactive effect with job components, job demands in particular, to influence a range of variables relating to physical and mental health as well a job-related attitudes. The nature of these effects, however, suggests a dissociation in the ways that different independent variables influence a range of indices of well-being and affect. This result requires further investigation since there are important theoretical implications which will follow if the data are replicable.

In order to examine such complex effects, in addition to the need for more longitudinal studies, it is also important that standardized measures of job components are developed so that levels of stress exposure can be equated and their impact assessed across organizational settings.

Finally, the data reported in this study suggest that some effective stress management may be undertaken by adopting selection strategies which take into consideration individual characteristics. In view of the fact that individual stress management programmes are of unproven benefit (Murphy 1986, 1988) such an approach is recommended especially for those organizations which are highly constrained in the services that must be performed.     

Is there support for curvilinear relationships between psychosocial work characteristics and mental well-being? Cross-sectional and long-term data from the Whitehall II study

This study aimed to test whether curvilinearity would add explanatory power to the long-term relationships between job characteristics and mental well-being. The study was based on cross-sectional and longitudinal data from phases 3 and 5 of the Whitehall II sample (N=4154 for job satisfaction and 6000 for context-free mental well-being, mean follow-up 5.8 years). The curvilinear components of the job characteristics were introduced after controlling for the baseline outcome measure, demographic factors, and the linear measures of the job characteristics. The cross-sectional analyses showed only a curvilinear association with the expected U-shape between job demands and context-free mental well-being. The longitudinal analyses showed no curvilinear relationships between the job characteristics and context-free mental well-being. While small non-linear relationships were found between social support and decision latitude and job-related mental well-being, the shape of these relationships was the reverse of that expected. Post hoc analyses revealed that only the positive segment of the relationship between decision latitude and job satisfaction was significant, while both segments of the relationship between social support and job satisfaction were significant. The findings from this study, based on a large sample with high variety in working conditions, provide little support for the assumption of curvilinearity in the long-term relationship between psychosocial working conditions and mental well-being. This has practical implications, as if associations are linear this would indicate that it would be reasonable to take a population (rather than individually targeted) approach to stress management interventions.