Employment is one of the main activities of industrialized societies and an essential factor in ensuring equal opportunities through the participation of citizens in economic, social, and cultural life [1
]. Work organizes people’s lives and provides income. Numerous studies have also shown that work promotes well-being and provides a means for individual satisfaction and achievement [3
]. Thus, it can be said that for most, work represents a fundamental dimension of human existence.
People with intellectual disability (ID) are not an exception. Intellectual disability includes different conditions classifiable according to the International Classification of Diseases ICD-11 [7
] as disorders of intellectual development (6A00). These disorders are a group of etiologically diverse conditions originating during the developmental period characterized by significantly below average intellectual functioning and adaptive behavior. A similar definition is included in the DSM-5 manual [8
] where the condition is called intellectual disability. According to the International Classification of Functioning, Disability and Health (ICF), this condition is related to limitations in general mental functions, which are required to understand and constructively integrate the various mental functions including all cognitive functions and their development over the life span [9
]. Finally, The American Association on Intellectual and Developmental Disabilities (AAIDD) [10
] defines it as a disability characterized by significant limitations in both intellectual functioning and in adaptive behavior that covers many everyday social and practical skills. This disability originates before the age of 18. All these definitions share common elements to consider that this condition implies limitations that require support to guarantee the same rights as for the general population.
In relation to employment, the Convention on the Rights of Persons with Disabilities [11
] recognizes “the right of persons with disabilities to work, on an equal basis with others; this includes the right to the opportunity to gain a living by work freely chosen or accepted in a labor market and work environment that is open, inclusive, and accessible to persons with disabilities” (p. 19). The 2030 Sustainable Development Agenda is based on the commitment to leave no one behind. To achieve this goal, the full inclusion and effective participation of people with disabilities in society and development are necessary [12
]. Thus, the objective 8.5 of Sustainable Development aims “by 2030 to achieve full and productive employment and decent work for all women and men, including young people and people with disabilities, as well as equal remuneration for work of equal value” [13
The European Parliament, on its resolution on the European Disability Strategy post-2020 [14
] states that employers must be supported and encouraged to ensure that persons with disabilities are empowered. It calls on the commission to ensure that the post-2020 strategy will especially promote guaranteed access to employment. It also calls on the commission to recognize, promote, and protect inclusive enterprises to create permanent employment for people with disabilities in the labor market, stresses the potential of social economy enterprises and organizations to facilitate labor market inclusion for persons with disabilities, and calls on the commission to provide targeted support from the European Social Fund for the social economy. However, the employment rates of this group are still significantly lower than those of the non-disabled population or those with other types of disabilities (e.g., physical or sensory). Consequently, people with ID are underrepresented in the labor force [15
]. Nevertheless, an increasing number of adults with ID are entering employment and engaging in productive activity [18
], either within normalized, community-integrated enterprises or in sheltered employment [20
For more than two decades, numerous studies have shown that people with ID can successfully perform work and contribute to the community [16
]. In addition, these individuals also report their satisfaction, and most indicate that they are highly motivated to work [27
]. In turn, work has been found to improve self-esteem, self-determination, social inclusion, social and professional networks, income, health, well-being, and quality of life [22
]. All this underlines the importance of obtaining and maintaining employment for this group. Consequently, for decades, the literature has been more focused on assessing the benefits of having a job [33
] rather than on analyzing the characteristics of the working environment, which contribute to personal and organizational outcomes [37
]. In most cases, studies did not ask the person with ID about his/her own work experience. Instead, they gathered information from third parties (supervisors, job coaches, or people from the family environment). This has been considered one of the main weaknesses of research in this field, as the opinions of these workers were overlooked in most studies [15
Nowadays, research on these topics is still scarce, and there is a need to increase knowledge regarding the factors in the work environment that enhance or hinder occupational health and satisfaction, from the perspective of the worker with an intellectual disability. Over the last decade, there have been numerous attempts to fill this research gap. In fact, an interesting body of work has emerged whose aim has been to analyze the characteristics and factors in the work environment related to the well-being and satisfaction experienced by workers with ID [38
]. Job satisfaction has been one of the most analyzed constructs within organizational psychology [45
]. In the field of intellectual disability, it is also a relevant topic where a recent systematic review concluded that the factors involved in job satisfaction of workers with ID are the same as those found in the non-disabled population [46
]. However, studies in this group are scarce, and further research is needed [20
The most widely used definition of job satisfaction was proposed by Locke [47
], who defines it as “a pleasurable or positive emotional state resulting from the appraisal of one’s job or job experience” (p. 1300). This definition emphasizes the affective dimension of the construct while incorporating cognitive and attitudinal elements. Therefore, many interrelated agents impact a worker’s experienced job satisfaction. Job satisfaction is associated with personal (e.g., expectations, dispositional factors, sociodemographic), situational (e.g., job characteristics, social supports, physical and psychological demands), and socio-cognitive (e.g., the appraisal of these job factors) characteristics.
Although earlier research on this matter in the field of intellectual disability emerged at the end of the 1980s [48
], having a job, especially in integrated contexts, was considered reason enough to experience job satisfaction. In fact, a large body of research concluded that people with ID who worked in integrated employment experienced greater job satisfaction than their peers who worked in more segregated environments, or unemployed people from the general population [26
Satisfaction also seems to depend on personal factors, as well as on characteristics and conditions in which the work is done but, above all, on the appraisal of the workers themselves of these factors, in particular the nature of the tasks, working conditions, physical and psychological demands, social relations, and perceived support from colleagues and supervisors. Likewise, features such as the perception of autonomy, self-determination, decision-making, independence, and motivation have been found to be related to job satisfaction in the scarce research carried out in this field [19
]. Those features, when perceived negatively, can become stress-inducing risk factors and jeopardize worker health and organizational outcomes. Very few studies have analyzed the influence of job characteristics on the stress experienced by workers and its impact on work well-being. In these cases, it has been shown that workers with ID who perceive job demands more intensely also experience greater job stress, which negatively impacts their productivity and quality of work life [41
Therefore, in order to determine the type of support that people with ID need in their workplace, it is necessary to deepen the study of job satisfaction and associated factors. It is also advisable to adopt an integrative and multidimensional framework that will allow determining the nature of the associations between its variables. The Job Demands–Resources Theory (JD-R), proposed by Demerouti et al. [56
] provides an appropriate framework. Its application to the field of intellectual disabilities is still rather limited [20
Job Demands–Resources (JD-R) Theory
The JD-R theory is an extension of the Job Demand–Resources model [56
] which, in turn, draws on the theories of job design and occupational stress [58
]. It is a theoretical model that helps understand, explain, and predict aspects of employee well-being and job performance, including job satisfaction [58
]. One characteristic of JD-R theory is its flexibility [60
]. This allows it to be applied in any occupational environment, to any professional group and detect the consequences of those specific environments on occupational health and performance, allowing for interventions to improve the well-being of employees. Therefore, its application in the field of intellectual disability is relevant for the advancement of research in this field of study.
The theory is based on a series of specific propositions [61
]. The first assumption establishes that work environments and characteristics can be divided into two categories: job demands and job resources. Job demands refer to those “physical, psychological, organizational or social aspects of the job that require sustained physical or mental effort and are therefore associated with certain physiological and psychological costs” [56
] (p. 501). Job demands can be an obstacle when they require a high effort from the worker [58
]. Job resources refer to “physical, psychological, organizational or social aspects of work that can: (a) reduce job demands at the associated physiological and psychological costs, (b) be functional in achieving work goals, or (c) stimulate personal growth, learning and development” [57
] (p. 312), [56
] (p. 501). Job resources are not only necessary to meet demands but also have their own effect [58
]. Social support from coworkers or supervisors, obtaining feedback on performance, and having autonomy are examples of resources. Numerous investigations with ID workers have identified job demands and resources associated with their well-being and job satisfaction [19
A second proposition of the JD-R theory is that job demands and job resources develop two relatively independent processes, namely: health impairment and motivational process. The first process occurs in situations where high job demands and low job resources leads to exhaustion, which is the core dimension of burnout [62
]. This is considered the most important predictor of the negative impact of stress on worker’s health [63
]. Thus, prolonged exposure to occupational demands produces a negative effect on health and organizational outcomes through burnout. Thus, in accordance with this proposition, we predict the following:
Hypothesis 1 (H1).
Job demands will be negatively related to job satisfaction through their impact on exhaustion (i.e., core dimension of burnout).
On the other hand, the motivational process relates to job resources. For example, adequate job resources stimulate worker motivation and leads to engagement which, in turn, generates positive work outcomes that impact on the individual and the organization (e.g., through increased work performance and commitment). Job resources are the most important predictors of engagement [60
]. This construct is defined as a “positive, work-related state of mind characterized by vigor, dedication and absorption” [65
] (p. 4), with vigor and dedication being the core dimensions of engagement [60
]. Therefore, work environments that promote resources stimulate the intrinsic motivation of workers and, in turn, increase, their involvement and effort toward tasks, thus achieving greater well-being and better organizational results. Thus, we predict the following:
Hypothesis 2 (H2).
Job resources will be positively related to job satisfaction through their impact on work engagement (with vigor and dedication as the main motivational process).
These two processes have been identified in empirical and meta-analytical studies [62
]. Despite evidence that workers with intellectual disability may experience burnout and engagement in their workplaces [54
], no research has replicated this dual pathway proposed in the JD-R model. The recent work carried out by Ybema et al. [55
] is the only exception, although they use a non-representative sample of workers with ID, which makes it difficult to generalize.
JD-R theory also postulates that job demands and job resources interact in predicting well-being. Here, resources buffer the impact of demands on occupational health and well-being; that is, employees with more resources will better cope with workplace demands and will experience less discomfort and exhaustion. Some studies on workers without disabilities have shown that having work resources can lessen the impact of demands on exhaustion [71
]. However, support for this proposition has not always been found [59
]. The few studies conducted with workers with disabilities also provided contradictory results [54
], so further research into these relationships is required. Accordingly, we predict the following:
Hypothesis 3 (H3).
Job resources will reduce exhaustion.
The robustness of this model has been demonstrated in numerous studies and with different professional groups [59
]. A recent meta-analysis of longitudinal studies suggest that the model provides an excellent theoretical basis for assessing employee well-being in any professional field [70
]. However, the JD-R model has been sparsely used. In the study by Flores at al. [40
], it was used to analyze quality of work life in workers with intellectual disability in sheltered workshops and supported employment. Likewise, Akkerman et al. [39
] used it to understand the influence of job characteristics and personality traits on the job satisfaction experienced by workers with ID. Finally, Ybema et al. [55
] utilized it as a framework to explain the well-being and productivity of workers with diverse disabilities in sheltered employment. All these studies assessed the limited variables of the model [20
] or utilized insufficient and unrepresentative samples [55
]. Therefore, it is necessary to increase research and provide evidence on the applicability of the JD-R model to workers with intellectual disability, using larger samples belonging to the two most common employment modalities in the hiring of this group (sheltered workshop vs. supported employment). This would make the theory more robust and will allow the design of specific proposals for intervention to improve the occupational health of this group.
This work aims to use the Job Demands–Resources theory (JD-R) [56
] with a large group of workers with ID belonging to the two most used employment modalities in the hiring of this group (sheltered vs. integrated). More specifically, this study aims to investigate the fit of the two-way process established in the JD-R theory to explain the job satisfaction of these workers. It also aims to explore its appropriateness and validity in the prediction of well-being and job satisfaction, using the procedure of structural equations. An additional aim is to demonstrate the appropriateness of some of its fundamental postulates [58
]. Therefore, in accordance with previous predictions derived from JD-R theory, we also predict the following:
Hypothesis 4 (H4).
The health impairment and the motivational process stated in JD-R theory will function similarly in both employment modalities under study.
The main objective of this study was to test the adequacy of the Job Demands–Resources (JD-R) model [57
] in workers with intellectual disability belonging to the two most common employment options, namely, sheltered workshops and supported employment. The results allowed us to corroborate two of the main propositions of the JD-R model. Specifically, we found that in work environments, there are job demands and resources that impact the well-being and job satisfaction through burnout and engagement, respectively. These results provide support for the two-way process formulated in the JD-R model regarding the existence of two independent, although related, processes (health impairment and motivational) that explain the well-being of workers with intellectual disability. In fact, the model jointly explains 47% of the variance in job satisfaction. These results are consistent with those recently obtained by Ybema et al. [55
]. Our study provides further evidence on the suitability of the JD-R theory in the prediction of job satisfaction using the structural equation procedure in a large sample of workers with ID. As far as we know, there are no previous studies that have used a multi-sample of workers with intellectual disability to contrast the core assumptions of the JD-R theory, this being one of the main contributions of this study.
In line with the health impairment process [58
], and according to our first hypothesis, the results show that situations with high psychological demands, such as work overload, cause exhaustion for workers with ID that can lead to poorer job satisfaction. Previous studies have reached similar conclusions, demonstrating that prolonged exposure to job demands and the resulting burnout lead to poorer personal and organizational outcomes [40
Regarding the motivational process [58
], the results support the second hypothesis, confirming the two-way process. Furthermore, we found that together with work engagement, job resources are better predictors of job satisfaction than job demands. These results agree with previous studies [39
]. They also stress the role of job resources in the prediction of job satisfaction and motivation, as postulated in the JD-R theory [57
]. Our findings allow us to confirm that job resources and especially, work engagement, are key in the motivation of workers with ID, and they contribute to their well-being in the workplace.
Resources can also be helpful in mitigating burnout and exhaustion experienced by workers with intellectual disability, as stated in the third hypothesis. The existence of an inverse and significant association between job resources and exhaustion supported our predictions. However, contrary to our expectations, no association was found between job decision latitude and exhaustion. This result offers partial support to our hypothesis and is in line with some of the conclusions drawn by the authors of the JD-R theory about the weak negative impact that some resources have on burnout [61
]. A possible explanation could be that job decision latitude was not perceived by ID workers as a job resource but rather as a job demand if they feel that they lack self-management skills. Excessive support provided by supervisors could also help explain these limitations [33
]. In addition, some recent research did not find any significant association between job resources and burnout [55
]. All of the above suggests the need for further research in this regard.
This study has demonstrated that the two processes established in the JD-R theory are valid and similar for the two employment modalities. Specifically, the results showed that job satisfaction is the result of the appraisal of the adequate balance between job demands and resources. The invariance model was reached both at the configural and metric level. However, in this case, as in many other multi-group studies, the invariance did not reach the scalar level [62
]. This suggests that the way of responding and rating the items may be higher or lower depending on the group, thus reflecting differences between the individual responses to items. Similar results were also obtained in most studies that have contrasted the JD-R model in different groups of workers without disabilities [56
Regarding the job satisfaction experienced by these employees, the results revealed the existence of significant differences in the two groups analyzed, with workers from sheltered workshops having lower job satisfaction. They also perceived higher psychological demands, fewer job (job decision latitude) and interpersonal (social support from colleagues) resources, and less work engagement. These results offer support to those in favor of transforming the initiatives of sheltered workshops into more inclusive employment services [85
]. However, and in line with previous studies [38
], most of the workers experienced high levels of job satisfaction. Although other studies did not find differences between work alternative and job satisfaction of employees with disabilities [38
], the tasks that ID employees usually perform in the different work modalities could help explain the current findings. It could also be related to the concept of informed choice. People with disabilities must be provided with opportunities to exercise informed choice in decision-making and regarding employment services, to promote inclusion and integration into society [87
]. In this regard, supported employment initiatives seem to offer more opportunities for choosing and feeling part of the community [88
]. Furthermore, additional personal, contextual, or organizational factors (e.g., sociodemographic variables, personality traits, perceived self-efficacy, length of time in the position, job choice, salary, type of contract, etc.) could also be relevant to predict job satisfaction. Further studies on the different variables that could explain these differences are advisable.
It is also necessary to mention several limitations present in our study. First, participants were recruited using a non-probabilistic convenience sampling process, which limits the generalizability of our findings. In addition, levels of intellectual disability ranged from mild to moderate, so further studies are required to replicate current findings with the most severe levels of intellectual disability. A second limitation relates to its cross-sectional design. This implies that the observed associations in the model must be interpreted with caution and not establish causal inferences, since the existence of reciprocal relationships or inverse causalities could also be possible. Although longitudinal designs are desirable, the hypotheses tested in the present study require large datasets that are often difficult to collect in those research designs [70
]. Utilizing shorter time intervals (for example, 2 to 6 months) could be a possible solution, although no longitudinal study has yet been carried out with this population that allows us to determine the best time interval.
Another limitation is the type of measures used. In our case, we have only used self-report measures administered by interview. Additional objective and psychophysiological measures could useful to corroborate the two processes established in the model. Thus, in the case of the pathway of deterioration in health, it could be interesting to include some psychophysiological record (e.g., blood pressure) to help identify the physiological responses to chronic stress situations. Regarding the motivational pathway, objective indicators (e.g., absenteeism, salary) could be considered. So far, studies that include this type of measure are scarce and nonexistent in the disability field. Daily registers could also be used to collect information on demands and resources, thus allowing analyzing their temporal variation and its effect on well-being and satisfaction, as some incipient studies have shown [55
]. Likewise, studies using qualitative methodology could be useful to explore in depth the vision of workers with ID regarding other factors (e.g., choice of current job, experience in other jobs, view on the promotion of protected alternatives to more integrated alternatives, etc.) that could also be determinants of their job satisfaction.
Finally, the model explained 47% of the variance of job satisfaction. Therefore, more research is needed to determine other factors that may be involved in the job satisfaction of workers with intellectual disability. The inclusion of personality variables (e.g., self-efficacy, self-esteem, and optimism) as well as other job demands and resources not included in the model (e.g., role conflict, performance training, self-determination), together with other features such as gender, age, level of disability, additional coexisting disabilities, type and intensity of required supports, choice of employment, previous experience or length of time in the job, could help increase the explanatory power on the predictors of job satisfaction. The existence of psychometrically validated measures such as the Support Intensity Scale in the Spanish context may promote the inclusion of this variable in further studies [89
Despite these limitations, the current findings have several practical implications both for improving the health and job satisfaction of employees with ID, and for organizations and professionals interested in promoting social inclusion and the quality of work life of these workers. First, different actions aimed at reducing the health impairment process in the presence of high job demands and low resources are suggested. One would be to seek an adequate match between the worker and job position. This means that, in addition to assessing the worker’s skills and abilities, workplace assessments must be carried out to determine the existing job demands [90
]. Teaching strategies for preventing and coping with psychosocial risks and stress in the workplace would be another one of the actions aimed at improving the occupational health of these workers. Psychoeducation, relaxation techniques, problem-solving skills, time management, and dealing with dysfunctional thoughts could be effective strategies to reduce the impact of job demands on health and well-being.
Second, this study confirms the role that social support and work engagement play as elements that favor workplace well-being. Here, motivating workers through the recognition, acquisition, and development of job resources, both interpersonal (e.g., support from supervisors and colleagues) and personal or organizational (e.g., autonomy, variety of tasks, participation in decision-making) is of paramount importance to increase their satisfaction. The provision of adequate supports in the workplace will not only improve the functioning of the workers with ID, but it will also promote their personal and work outcomes as well as their quality of life [91
]. In this study, social support from supervisors is the labor resource that contributes the most to explaining job satisfaction. There is no doubt about the importance of this type of support for any worker [56
]. However, the way in which such support is provided needs to be underscored [38
]. A too directive style and oriented toward the goals, or alternatively, being too overprotective will not allow workers with ID to explore or use their personal and work resources, which can also generate stress. For its part, adopting a participative leadership style will allow them to discover and activate other relevant personal and work resources (e.g., control over the task). Here, encouraging the participation of workers, offering them regular feedback on their performance, and listening to their opinions will result in greater self-efficacy and performance.
Another significant support comes from co-workers. In our study, it contributed to mitigate stress and is perceived differently depending on the job alternative. In supported employment, it is widely demonstrated that the more natural the supports, the better the benefits for the worker and for the organization [23
]. In sheltered workshops, peer support is also valued as a key element to improve the quality of work life [75
]. This type of support not only fulfills an instrumental function but also an emotional function, as it is useful in alleviating the impact of demands on stress and burnout [92
]. Therefore, promoting social relations in the workplace, encouraging cooperative work, and enhancing the participation of workers in organized activities both inside and outside the work context are some initiatives that could favor personal relationships with coworkers.
Finally, work engagement constitutes a key element for achieving personal outcomes and work well-being. Therefore, providing stimulating and motivating work environments is crucial to improve job satisfaction. Fostering the personal resources of employees is an effective way to achieve this [93
]. Allowing the worker to take the initiative and make changes in executing tasks, stimulating self-efficacy by reinforcing the achievements and skills of the person, and promoting optimism, hope, and resilience are some strategies to promote it. Likewise, enhancing self-determination by helping persons with disabilities to see their life and work as something that they can influence and act on would undoubtedly contribute to increase their motivation, which in turn will result in greater personal and organizational outcomes.