Model of interaction between demands and control
Stress is the result of the interaction between high psychological demands and low decision-making freedom, that is, low control. The level of labor demands is usually derived from the production level of the company, while the level of control depends more on the organization chart (authority structure, responsibility system, etc.). High demand can come from the pace and speed of work, the amount of work, contradictory orders, conflicting demands, the need for concentration, the number of interruptions and dependence on the pace of others. And control refers to the set of resources that the worker has to face the demands;
According to the model, high stress occurs when conditions of high psychological demand and low control of decision-making occur together . The remaining categories of work would be low stress (low demand and high control), active (high demand and high control) and passive (low demand and low control). Therefore, work stress arises when work demands are high, and at the same time, the ability to control it (due to lack of resources) is low (Karasek, 1979) (see Figure 3.2).
This model has been associated with an increased risk of coronary heart disease, with psychological disorders, and with musculoskeletal disorders, especially in the upper extremities (Collins, Karasek & Costas, 2005). In contrast, work motivation increases as demands and control over work increase at the same time.
Model of interaction between demands, control and social supportJhonson and Hall (1988) and Karasek and Theorell (1990) expand the demand-control interaction model, introducing the social support dimension as a modulator, in such a way that a high level of social support at work reduces the effect of stress, while a low level increases it. The third modifying factor is the quantity and quality of social support that superiors and co-workers can give.
When it exists, and it is adequate, it can buffer part of the potential of the stressor generated by the combination of high demands or demands and low control. From this model, the prevention of work stress would be carried out by optimizing work demands, increasing the worker's control over their working conditions and increasing the social support of bosses, subordinates and colleagues (see Figure 3.3).
Social support has been used in many different ways, as a social network, as meaningful social contacts, as the possibility of having confident people to whom intimate feelings can be expressed, and as human companionship. And it has a general positive function on health and a buffer function on stress.
In social support, some authors (Schaefer et al., 1982) have distinguished between emotional, tangible and informational support, and others, such as House (1981), differentiated between emotional support (they are the samples of empathy, love and trust), instrumental ( are the tangible behaviors or actions aimed at solving the specific problem of the recipient), informative (consists of the useful information received to face the problem) and evaluative (it is information for self-evaluation or for social comparisons).
In any case, social support is made up of four factors: directive orientation, non-directive help, positive social interaction and tangible help (Barrera and Ainlay, 1983).
Therefore, social support at work refers to interpersonal relationships between colleagues, and between subordinates and bosses, and can be influenced and influence changes in the organization and the work environment.
Model of imbalance between demands, supports and restrictions
The model of imbalance between demands, supports and restrictions (Payne and Fletcher, 1983) establishes that work stress is the result of the lack of balance between the following three work factors: work demands (they represent the tasks and the work environment that contains stimuli technical, intellectual, social or economic), work supports (they are given by the degree to which the work environment contains available resources that are relevant to meet work demands. Support can be technical, intellectual, social, economic, etc.). ) and labor restrictions (limitations that hinder work activity due to the lack of resources and prevent the worker from facing the demands).
According to this model, stress occurs when there is no balance between these work factors. Therefore, demands are not stressful if the job provides good levels of support and low levels of restrictions. In fact, high demands can be positive under appropriate circumstances since, in addition to being stimulating, they allow the implementation of skills.
Low skill utilization (preparation, ability, etc.) and boredom are some of the most powerful stressors, and usually occur in work environments where supports are low and restrictions are high. A practical implication of the model is that very demanding jobs (high demands) can be made less stressful without the need to reduce the level of demands, increasing the level of supports and / or reducing the level of restrictions.
Model of mismatch between worker demands and resources
Work stress is due to the lack of adjustment between the demands and demands of work to be performed and the resources available to the worker to satisfy them (Harrison, 1978). This model proposes that what produces stress is a mismatch between the demands of the environment and the resources of the workers to face them. The stress process starts from the existence of an imbalance perceived by the worker between professional demands and the resources and capacities of the worker himself to carry them out. And it allows to identify three important factors in the generation of work stress:
- the resources available to the worker to meet the demands and demands of the work environment
- the perception of said demands by the worker
- the demands themselves
This model (Matteson and Ivancevich, 1987) distinguishes six components: stressors, including not only organizational factors (intrinsic factors of the position, organizational structure and control, the reward system, the human resources system and leadership ), but also the extra-organizational (family relationships, economic and legal problems, etc.); These stressors affect the cognitive appreciation-perception of the situation by the worker; this, in turn, affects the physiological, psychological and behavioral results of this cognitive appreciation-perception, and these, in turn, on the consequences, both those referred to the health of the individual and those referred to their performance in the organization.
Individual differences are considered as modulating variables that affect the relationships between stressors and cognitive appreciation-perception; between cognitive appreciation-perception and results; and between results and consequences.
Effort-reward imbalance model
The effort-reward model postulates that work stress occurs when there is high effort and low reward(Siegrist, 1996). And it has been operationalized, focusing on the variables that sustain it: extrinsic effort variables, intrinsic effort variables and reward variables. High effort at work can be extrinsic (demands and obligations) or intrinsic (high motivation with coping). And the low reward is a function of three fundamental types of rewards: money, esteem, and status control. This third type of reward reflects the powerful threats produced by job loss or job degradation. It is, therefore, a reward in terms of prospects for promotion, job security, and the absence of risk of decline or loss of employment.
The model predicts that work stress occurs because there is an imbalance (balance) between effort and the reward obtained. Siegrist (1996) points out that work stress is generated from a high effort, an inadequate salary and a low control over one's own occupational status. And it is assumed that under these conditions, both the worker's self-esteem and self-efficacy will be seriously undermined. Siegrist's model has been associated with risk of cardiovascular disease and impaired mental health (Smith et al., 2005).