Organizations need energetic and dedicated employees: people who are engaged with their work. These organizations expect proactivity, initiative and responsibility for personal development from their employees.
Kahn  was the first scholar to define “personal engagement” as the “…harnessing of organization member’s selves to their work roles: in engagement, people employ and express themselves physically, cognitively, emotionally and mentally during role performances” (p. 694). Based on this definition a questionnaire was developed that assesses three dimensions: cognitive, emotional and physical engagement.
There are two schools of thought with regard to the definition of work engagement. On the one hand Maslach and Leiter () assume that a continuum exists with burnout and engagement as two opposite poles. The second school of thought operationalizes engagement in its own right as the positive antithesis of burnout. According to this approach, work engagement is defined as a positive, fulfilling, work-related state of mind that is characterized by vigor, dedication, and absorption. Vigor is characterized by high levels of energy and mental resilience while working, the willingness to invest effort in one’s work, and persistence even in the face of difficulties; dedication by being strongly involved in one's work, and experiencing a sense of significance, enthusiasm, inspiration, pride, and challenge; and absorption by being fully concentrated and happily engrossed in one’s work, whereby time passes quickly and one has difficulties with detaching oneself from work.
As a unique concept
Work engagement as measured by the UWES is positively related with, but can nevertheless be differentiated from, similar constructs such as job involvement and organizational commitment, in-role and extra-role behavior; personal initiative, Type A, and workaholism. Moreover, engaged workers are characterized by low levels of burnout, as well as by low levels of neuroticism and high levels of extraversion. Also they enjoy good mental and physical health.
Trait versus state
Generally, work engagement is conceptualized as a relatively stable phenomenon. This can be explained by the presence of specific job and organizational characteristics. However, engagement is not a fixed state: the level of engagement can even fluctuate on a weekly  or day-to-day basis. Increasingly, attention is being paid to these short-term fluctuations by conducting experience sampling studies and diary studies. Christian, Garza, and Slaughter (2011) meta-analyzed over 90 engagement research studies. They found that engagement is distinct from job satisfaction, organizational commitment, and job involvement.
The three aspects of work engagement (vigor, dedication and absorption) are assessed by the Utrecht Work Engagement Scale (UWES ), which is currently available in 20 languages and can be used freely for non-commercial purposes. In addition a short form  and a student version  are available. The reliability and validity of the UWES is documented is various studies (for an overview see ).
Research has identified two key sets of variables that drive work engagement:
- Job resources: Work engagement is found to be positively associated with job resources such as social support from co-workers and from one’s superior, performance feedback, coaching, job control, task variety, opportunities for learning and development, and training facilities. These resources are helpful in reducing the impact of job demands on strain, but they are also useful in the achievement of work goals, and they stimulate learning, personal growth and development. One consistent finding is that the motivational potential of job resources is particularly salient in the face of high job demands.
- Example: In a longitudinal study among 2555 Finnish dentists, researchers found that job resources lead to work engagement, which in turn had an influence on the level of personal initiative and consequently on work-unit innovativeness.
- Personal resources: personal resources, such as optimism, self-efficacy and resilience are functional in controlling the environment and exerting impact on it in a successful way. Furthermore, engaged employees have several personal characteristics that differentiate them from less engaged employees. Examples are extraversion, conscientiousness and emotional stability. Psychological capital  also seems to be related to work engagement.
- Example: Xanthopoulou, Bakker, Demerouti, and Schaufeli (2007)  studied Dutch technicians’ work engagement in relation to three personal resources (self-efficacy, organizational-based self-esteem, and optimism). Results indicated that these resources were related to work engagement.
For an overall model of work engagement, see Bakker & Demerouti (2008).
Engagement is related to better performance. For instance, engaged contact workers from hotels and restaurants produce better service quality as perceived by their customers; the more engaged university students feel the higher their next year’s Grade Point Average; the higher the level of engagement of flight attendants, the better their in- and extra-role performance on the flight; and the more engaged restaurant workers, the higher the financial turnover of the shift. Other research has shown links between supervisor-ratings of performance and the work engagement of teachers (Bakker and Bal, 2010 ) and administrative workers in financial services (Yalabik et al., 2013 ). Salanova, Agut and Peiró (2005) found a positive relationship between organization resources, work engagement and performance among employees, working in Spanish restaurants and hotels.
There are several possible reasons why engaged employees show higher performance than non-engaged employees:
- They often experience positive emotions;
- They experience better health;
- They create their own job and personal resources;
- They transfer their engagement to others (cross-over).
- Bakker, A.B., & Leiter, M.P. (Eds.) (2010). Work engagement: A handbook of essential theory and research. New York: Psychology Press
- Kahn, W. A. (1990). Psychological conditions of personal engagement and disengagement at work. Academy of Management Journal, 33, 692-724
- May, D. R., Gilson, R. L., & Harter, L. M. (2004). The psychological conditions of meaningfulness, safety and availability and the engagement of the human spirit at work. Journal of Occupational and Organizational Psychology, 77, 11-37
- Maslach, C., Jackson, S.E., & Leiter, M. (1997). The truth about burnout: How organizations cause personal stress and what to do about it. San Franscisco, CA: Jossey-Bass
- Bakker, A.B., Demerouti, E. (2007). Using the Job Demands-Resources model to predict burnout and performance. Human Resource Management, 43, 83-104
- Schaufeli, W.B., Salanova, M., González-Romá, V., & Bakker, A.B. (2002). The measurement of Engagement and burnout: A confirmative analytic approach
- Schaufeli, W.B., Salanova, M., González-Romá, V., & Bakker, A. B. (2002). The measurement of Engagement and burnout: A confirmative analytic approach. Journal of Happiness Studies, 3, 71-92
- Hallberg, U., & Schaufeli, W.B. (2006). “Same same” but different: Can work engagement be discriminated from job involvement and organizational commitment? European Journal of Psychology, 11, 119-127
- Schaufeli, W.B., Taris, T.W., & Bakker, A. (2006). Dr. Jekyll and Mr. Hyde: On the differences between work engagement and workaholism. In: R. Burke (Ed), Work hours and work addiction (pp. 193-252). Edward Elgar: Northampton, UK
- Salanova, M., & Schaufeli, W.B. (2008). A cross-national study of work engagement as a mediator between job resources and proactive behavior: A cross-national study. International Journal of Human Resources Management, 19, 226-231
- Hallberg, U., Johansson, G. & Schaufeli, W.B. (2007). Type A behaviour and work situation: Associations with burnout and work engagement. Scandinavian Journal of Psychology, 48, 135-142
- Schaufeli, W.B., Taris, T.W., & Van Rhenen, W. (2008). Workaholism, burnout and engagement: Three of a kind or three different kinds of employee well-being? Applied Psychology: An International Review, 57, 173-203
- González-Roma, V., Schaufeli, W.B., Bakker, A., Lloret, S. (2006). Burnout and engagement: Independent factors or opposite poles? Journal of Vocational Behaviour, 68, 165-174
- Langelaan, S., Bakker, A.B., Van Doornen, L.J.P. & Schaufeli, W.B. (2006). Burnout and work engagement: Do individual differences make a difference? Personality and Individual Differences, 40, 521-532
- Macey, W.H., & Schneider, B. (2008). The meaning of employee engagement. Industrial and Organizational Psychology, 1, 3-30
- Bakker, A.B., & Bal, P.M. (in press). Weekly work engagement and performance: A study among starting teachers. Journal of Occupational and Organizational Psychology
- Bakker, A.B., & Xanthopoulou, D. (2009). The crossover of daily work engagement: Test of an actor-partner interdependence model. Journal of Applied Psychology, 94, 1562–1571
- Xanthopoulou, D., Bakker, A.B., Demerouti, E., & Schaufeli, W.B. (2009). Work engagement and financial returns: A diary study on the role of job and personal resources. Journal of Occupational and Organizational Psychology, 82, 183-200.
- Xanthopoulou, D., Bakker, A.B., Heuven, E., Demerouti, E., & Schaufeli, W.B. (2008). Working in the sky: A diary study on work engagement among flight attendants. Journal of Occupational Health Psychology, 13, 345-356.)
- Sonnentag, S., Dormann, C., & Demerouti, E. (2010). Not all days are created equal: The concept of state work engagement. In A.B. Bakker & M.P. Leiter (Eds.), Work engagement: A handbook of essential theory and research. New York: Psychology Press
- Schaufeli, W.B., Bakker, A.B. & Salanova, M. (2006). The measurement of work engagement with a short questionnaire: A cross-national study. Educational and Psychological Measurement, 66, 701-716
- Schaufeli, W.B., Martínez, I., Marques Pinto, A. Salanova, M. & Bakker, A.B. (2002). Burnout and engagement in university students: A cross national study. Journal of Cross- Cultural Psychology, 33, 464-481
- Schaufeli, W.B. 2007 pp. 135-177
- Demerouti, E., & Bakker, A.B. (2008). The Oldenburg Burnout Inventory: A good alternative to measure burnout and engagement. In J. Halbesleben (Ed.), Handbook of stress and burnout in health care (pp. 65-78). New York: Nova Science Publishers.
- Demerouti, E., Mostert, K., & Bakker, A.B. (in press). Burnout and work engagement: A thorough investigation of the independency of the constructs. Journal of Occupational Health Psychology
- Bakker, A.B. & Demerouti, E. (2008). Towards a model of work engagement. Career Development International, 13, 209-223
- Hakanen, J.J., Perhoniemia, R., and Toppinen-Tannera (2008). Positive gain spirals at work: From job resources to work engagement, personal initiative and work-unit innovativeness. Journal of Vocational Behavior, 73, 1, 78-91
- Xanthopoulou, D., Bakker, A.B., Demerouti, E., & Schaufeli, W.B. (2007). The role of personal resources in the job demands-resources model. International Journal of Stress Management, 14, 121-141
- Salanova, M., Agut, S., & Peiró, J.M. (2005). Linking organizational resources and Work engagement to employee performance and customer loyalty: The mediating role of service climate. Journal of Applied Psychology, 90, 1217-1227
- Salanova, M., Bresó, E. & Schaufeli, W.B. (2005). Hacia un modelo espiral de la autoeficacia en el estudio del burnout y Engagement [Towards a spiral model of self-efficacy in burnout and engagement research] Ansiedad y Estrés, 11, 215-231
- Xanthopoulou, D., Bakker, A.B., Heuven, E., Demerouti, E. & Schaufeli, W.B. (2008). Working in the sky: A dairy study among flight attendants. Journal of Occupational Health Psychology, 13, 345-356
- Xanthopoulou, D., Bakker, A.B., Demerouti, E. & Schaufeli, W.B. (2009). Work engagement and financial returns: A diary study on the role of job and personal resources. Journal of Organizational and Occupational Psychology, 82, 183-200.
- Bakker, A.B. and Bal, P.M. (2010). Weekly work engagement and performance: A study among starting teachers. Journal of Occupational and Organizational Psychology, 83, 189-206.
- Yalabik, Z.Y., Popaitoon, P., Chowne, J.A. & Rayton, B.A. (2013). Work engagement as a mediator between employee attitudes and outcomes. International Journal of Human Resource Management, 24, 2799-2823.
- Salanova, M., Agut, S. & Perió, J.M. (2005). Linking organizational resources and work engagement to employee performance and customer loyalty: The mediation of service climeate. Journal of Applied Psychology, 90, 1217-1227.
- Bakker, A.B. (2009). Building engagement in the workplace. In R. J. Burke & C.L. Cooper (Eds.), The peak performing organization (pp. 50-72). Oxon, UK: Routledge
- Geurts, S.A.E., & Demerouti, E. (2003). Work/Non-work interface: A review of theories and findings. in M. Schabraq, J. Winnubst & C.L. Cooper (Eds.), The handbook of work and health psychology (2nd ed.; pp. 279-312). Chichester: Wiley.
- Halbesleben, J.R., Harvey, J. & Bolino, M.C. (2009).Too engaged? A conservation of resources view of the relationship between work engagement and work interference with family. Journal of Applied Psychology, 94(6), 1452-65.