Within the classical challenge–hindrance framework (Cavanaugh et al. 2000), work stressors are a priori classified in hindrance or challenge stressors. This study shows that, contrary to a priori classifications of work stressors, work demands are simultaneously challenging and hindering. Aside from individual characteristics and resources, the level and balance of hindrance and challenge components embedded in a demanding situation depends on organizational and task-related boundary conditions such as the level of social support and job control provided. In our study, challenge components were positively related to work satisfaction and negatively related to burnout, whereas hindrance components were negatively associated with work satisfaction and positively related to burnout. With one exception (challenge appraisal of task complexity is not significantly related to burnout), these independent relationships between challenge and hindrance appraisal and outcome variables hold, even when adjusted for the intensity of the appraised work demands and other control variables (age, sex, and occupational status). With respect to the four work demands considered in our study (time pressure, interruptions, task complexity, and responsibility) however, challenge appraisals are more strongly associated with work satisfaction than with burnout, whereas hindrance appraisals are more strongly associated with burnout than with work satisfaction. Previous research with a priori classifications of challenge and hindrance stressors found that stressors categorized as challenge stressors are positively associated with favorable work attitudes, but negatively associated with health-related well-being (Boswell et al. 2004; LePine et al. 2004). In light of our findings, these results of previous research with a priori classifications of challenge stressors may reflect that, for some work demands, the positive effects of challenge components may outweigh the negative effect of hindrance components with respect to work attitudes, but also that the negative effects of hindrance components dominate the positive effects of challenge components with respect to health-related well-being.
Our results also confirmed some curvilinear relationships between demand intensity and appraisal. This was the case for challenge appraisal, but less so for hindrance appraisal, which was predominately linearly related to demand intensity.
With respect to task complexity, responsibility, and time pressure the type of curvilinear relationship with challenge appraisal predominately corresponds with Warr’s (1994) vitamin CE (constant effects) heuristic. An increase in these job demands is appraised as more challenging up to a certain degree, but additional increments beyond this certain threshold do not entail additional benefits. As hindrance appraisal is linearly related to these work demands, an increase in hindrance appraisal induced by growth of demand intensity is also accompanied by an increase of challenge appraisal for low or moderate demand intensity. Hence, negative indirect effects on well-being through the hindrance component of the work demand are opposed by positive indirect effects through the challenge component for low or moderate levels of demand intensity. However, further intensification of high levels of work demands provokes additional hindrance appraisal that is no longer accompanied by additional challenge appraisal. Therefore, at the first look the demand—challenge association of these two work characteristics could suggest that an increase at high levels brings no additional benefit but also no disadvantages. This however, would ignore the detrimental effect of the constantly rising hindrance component.
Whether the negative effects through the hindrance component will exceed the (static) positive effects through the challenge component of high demand levels, to some extent depends on other boundary conditions, such as job control, which were found to buffer the demand–hindrance relationship for responsibility and task complexity. However, because the hindrance component is generally more relevant for burnout and the challenge component is more relevant for work satisfaction, the average association between these two demands (task complexity and responsibility) is positive for work satisfaction, but negative with respect to psychological wellbeing.
Moreover, our findings suggest that depending on boundary conditions—such as the perceived social support or job control—the type of demand—challenge relationships may also turn from Warr’s vitamin CE to AD (additional decrement) characteristics. Such characteristics were found for work interruptions under conditions of low job control and for time pressure under conditions of high social support.
Under conditions of low job control, a medium level of interruptions is associated with high challenge appraisal, whereas lower and higher levels of interruptions are related to reduced challenge appraisal. Jett and George (2003) argued on the one hand that interruptions may conflict with employees’ objectives and goal attainment, but on the other hand may also provide stimulation, distraction, and information acquisition, especially for routine tasks. Hence, consistent with our results, higher levels of interruptions are associated with an increase of the hindrance component. In addition however, a moderate level of interruptions may be stimulating under conditions of low autonomy, whereas the positive aspects disappear at high levels of interruptions, because employees do not have flexible opportunities to synchronize interruptions with their core work objectives.
The challenge appraisal of time pressure is not statistically related to the level of time pressure under conditions of low social support. By contrast, when social support is high, increasing levels of time pressure, up to a certain degree, are related to increasing challenge appraisal. The challenge appraisal however, declines again at high levels of time pressure. These results are in accordance with activation theory (Gardener and Cummings 1988), which suggests that excessively low levels of time pressure may provoke boredom, meaning that challenge appraisal grows when time pressure increases from low levels. However, positive affect will decrease again for overly high levels of time pressure due to reduced performance and overload.
The results suggest that time pressure and interruptions include positive challenge components under specific conditions. But, although the challenge component would contribute to job satisfaction stronger than the hindrance component, the bivariate correlation between both demands and job satisfaction is negative. This is found, because the relation between demand intensity and challenge appraisal is either insignificant or nonlinear (dependent on boundary conditions), while hindrance appraisal grows steadily with demand intensity. Therefore the positive effects of these demands on work satisfaction are slightly outweighed by the negative effects in sum.
As stated above, contrary to challenge appraisal, hindrance appraisal is mainly linearly related to the intensity of work demands. Therefore, higher demand intensity is associated with higher hindrance appraisal for all considered work demands. These results are in line with arguments brought forward by LePine et al. (2005), who argued that the idea that stressors could be beneficial up to some point seems plausible for challenge stressors, but not for hindrance stressors. In accordance with theories on job control, the hindrance appraisal of task complexity, interruptions, and responsibility is buffered by higher job control. Due to the indirect effects of demand intensity through hindrance appraisal on work attitudes and strain, job control also buffers these indirect negative effects on well-being. Less evidence was found for a buffering effect of social support on hindrance appraisal, except for the hindrance appraisal of interruptions. Consistent with theoretical expectations the strength of the positive relationship between the intensity of interruptions and hindrance appraisal is reduced under conditions of high versus low social support. With respect to time pressure, the positive relationship between demand intensity and hindrance appraisal is unexpectedly amplified with higher social support. However, further inspection (Fig. 3g) shows that although hindrance appraisal grows faster with increasing time pressure under conditions of high social support, the level of hindrance appraisal is always lower for any level of time pressure under conditions of high support than under low support. A possible interpretation of this is that social support helps reduce the hindering aspects of time pressure, but that the power of this buffering effect is reduced with increasing levels of time pressure. Therefore, social support may reduce the hindrance appraisal of low or medium time pressure, but not that of high time pressure.
Finally, even after controlling for challenge and hindrance appraisals, the direct effects of demand intensity on the two outcome variables remain. All four variables of demand intensity show significant positive effects on burnout. Based on these results, it can be concluded that a higher intensity of work demands promotes higher psychological strain, irrespective of the individual appraisal of the demanding situation. This result is in line with conclusions drawn from other research (Webster et al. 2011) in that working conditions can be harmful for health independently and regardless of individual estimations, although the direct effects of demand intensity are weaker than the direct effects of hindrance appraisal. On the contrary, only one significant direct effect of demand intensity on work satisfaction is observed (higher responsibility is related to higher work satisfaction), which is also weak compared to the direct effect of challenge and hindrance appraisals. Hence, it can be concluded that, unlike strain, it is predominately the individual appraisal of a specific demand intensity that is relevant for work satisfaction. Moreover, in contrast to challenge and hindrance appraisals, only weak evidence is found for interaction effects between social support and job control with demand intensity, although both significant interaction effects are consistent with theoretical expectations. First, a significant interaction effect exists between responsibility and job control with respect to burnout, such that the positive effect of responsibility on burnout is buffered by higher job control for medium levels of responsibility. Hence, the linear relationship between responsibility and burnout under conditions of low job control becomes a u-shaped relationship (in accordance with the vitamin AD characteristic) under conditions of high control. Second, the positive effect of responsibility on work satisfaction is amplified by higher social support.
The weak evidence for the interaction effects among job control, social support, and demand intensity is in line with results of previous research (Häusser et al. 2010). Moreover, both of the significant interaction effects of the study are only confirmed when curvilinear relationships are considered and when adjusted for the challenge and hindrance appraisals of work demands (both effects are insignificant when the challenge and hindrance appraisals are excluded from the path models). Nevertheless, the results show stronger evidence for the interaction effects between job resources (social support and job control) and demands with respect to challenge and hindrance appraisal than with respect to the demand–outcome relationship. Hence, in accordance with the suggestions of others (Mackey and Perrewé 2014), it can be concluded that these job resources more likely alter the perception of work demands than their direct effects on work attitudes and psychological strain.
This study has certain limitations. As the results are based on self-reported measures in a cross-sectional study, inflations of the associations between appraisal and outcome variables through common method bias are possible. As mentioned by Webster et al. (2011), among others, some findings (regarding differential associations with appraisal, mediation, and moderation effects) cannot be explained by common method bias; nevertheless, further research using objective measures of outcome variables is needed to validate the results. However, in a previous diary study among nurses, Johnston et al. (2016) confirmed that the experienced stress associated with different work tasks significantly predicted physiological measures of health (heart rate) even when adjusted for work task classification.
Moreover, due to the cross-sectional design of our study, the causality of the relationships between appraisal and the other variables is theoretically derived but not accessible for empirical testing. Maxwell and Cole (2007) pointed out that analyses of mediation processes that unfold over time by utilizing cross-sectional data have a high risk of generating biased estimates. As Preacher and Kelley (2011, p. 108) pointed out, “this criticism is valid, and similar criticism apply to any effect size measure based on analysis of cross-sectional data when the process under study is a longitudinal one”. On the other hand, similar to our study, Paškvan et al.’s (2015) longitudinal study among employees of a bank confirmed that work intensification at time 1 explained subsequent emotional exhaustion and work satisfaction at time 2 through hindrance appraisal of work intensification. Also, in a recently published time-lagged study with a 4-month time distance among airline employees, Liu and Li (2018) confirmed that challenge appraisal mediated the relationship between job complexity and work-related outcomes (work motivation and task persistence) and that hindrance appraisal mediated the relationship between role conflict and both outcomes. They also confirmed that the indirect effect of job complexity on work motivation through challenge appraisal was moderated by respondents’ task efficacy. Hence, although replications of our presented results with longitudinal data are clearly necessary, previous longitudinal research has confirmed the fundamental causal assumptions of our cross-sectional research.
Aside from causality, the presented research shows that the same stressor intensity may be appraised differently by employees and this difference likely depends on other (often unknown) boundary conditions of the organizational setting. Moreover, after accounting for stressor intensity, it was found that stressor appraisal explains unique variance in outcome variables measured at the same time point. Hence, instead of inferring the relevance of work stressors from a priori categorizations, it is recommended to consider some kind of appraisal measures in psychosocial risk assessments, especially when these assessments are used to draw inferences about possible psychosocial hazards of workplaces.
Furthermore, due to limited space in the questionnaire, we only used single-item measures for challenge and hindrance appraisal and a two-item measure for job control. Future research could use multiple item measures for challenge and hindrance appraisal, such as those developed by Searle and Auton (2015), and a more comprehensive measure for job control to further validate the presented findings.
Finally, we tested complex moderated mediation models including linear-by-linear interactions, curvilinear effects as well as curvilinear-by-linear interactions. Procedures for detecting interaction effects are generally plagued with low statistical power (Shieh 2009). The problem of low power becomes even more pronounced when curvilinear effects and interaction effects are tested simultaneously (Moosbrugger et al. 2009). Therefore, it might be difficult to replicate our findings—especially the complex curvilinear-by-linear interaction effects—in future research (Anderson and Maxwell 2017). In order to guide future research, we conducted a power analysis using a Monte Carlo simulation (Thoemmes et al. 2010). We first estimated the power of our models given the sample size of n = 630. We then determined the sample size needed for adequate power (0.80). Although critically discussed in the literature (Anderson and Maxwell 2017), we used the results reported within this paper as starting values for the estimated (true) population effects. Following Cohen (1992), we categorized the reported effects as “no effect”, “very small effect” (uniquely explained variance (uev) = .01), “small effect” (uev = .02), “small to moderate effect” (uev = .078), “moderate effect” (uev = .13), “moderate to strong effect” (uev = .2), and “strong effect” (uev = .259). To avoid a power overestimation due to a potential overestimation of the effects within this study, we assumed lower values (that is, one effect size category below the initial category) for the curvilinear and interaction population effects. This strategy largely coincides with the safeguard power approach advocated by Perugini et al. (2014). We estimated two different models. The first one mimics the results for responsibility and task complexity and includes curvilinear effects of work demand on challenge appraisal and interaction effects of job control and work demand on hindrance appraisal. The second model corresponds to the results for time pressure and interruptions, which simultaneously includes curvilinear-by-linear interactions of work demand and control and support, respectively. Results show that our study has high power (.97) to detect curvilinear effects, but low power to detect linear-by-linear as well as curvilinear-by-linear interaction effects (ranging from .28 to .63). In order to have sufficient power to detect the linear-by-linear interaction effect, as well as the very small curvilinear-by-linear interactions, a sample size of n > 2.000 would be needed.