For decades psychology has been associated as dealing mainly with the treatment of mental illness, although other areas of research and application have existed since its origins. At the very end of the twentieth century a new approach in psychology gained popularity: positive psychology.
Positive psychology, the study of optimal human functioning, is an attempt to respond to the systematic bias inherent in psychology's historical emphasis on mental illness rather than on mental wellness (Seligman, 2002), mainly by focusing on two, forgotten but classical psychological goals:
Since Martin Seligman, a former head of American Psychological Association, chose positive psychology as the theme of his presidency term, more empirical research and theoretic development emerged in this field.
Two new branches of positive psychology are being implemented into the industrial-organizational world.
Drawing from positive psychology constructs and empirical research, four psychological resources were determined to best meet the POB scientific criteria: Hope, Efficacy, Resilience, and Optimism and were termed by Luthans and colleagues as psychological Capital or PsyCap  and as en Emotional Capital (Gendron B., 2002, 2004).
Emotional capital (EK), a capital in an economic sense: filling the gap of the Becker's Human capital measurement approach. It brings outcomes and makes a bridge between outcomes from psychology and economics by taking into account soft skills as the socio-emotional competencies described in emotional intelligence models from Goleman, Cherniss, Bar-on, Salovey & Meyer, Caruso, Sarni.
Positive psychological capital: an heritage versus capital. In combination, the four constructs making up PsyCap were empirically determined to be a second-order, core construct that had a stronger relationship with satisfaction and performance than each of the components by itself. The four components are defined as follows:
The link with Emotional Capital (EK): filling the gap of Becker's Human capital measurement. It's the economics approach of the psychological parts and behaviors skills of human beings not innate but produced. Precisely, The emotional capital (Gendron, 2004) relates to the set of emotional competencies defined on the emotional intelligence models and complete the human capital approach where such skills were missing in the Human capital evaluation and returns.
The emotional capital (EK) approach and concept is filling the gap of the Becker's Human capital measurement approach. It brings outcomes and makes a bridge between outcomes from psychology and economics. "Emotional Capital is the set of resources (emotional competencies) that inhere to the person useful for personal, social, professional and organizational development" (Gendron, 2004c). EK is a crucial capital as it impacts people's learning processes, especially for children and young people at risk, enables their balanced human development, which participates to better social cohesion, smoother human relationships, their future successful life in the society and already to their school retention and success.
Emotional capital has specific characteristics related to emotional competencies. Emotional capital is a crucial capital: more than an additional capital, it is also a booster capital. If social, cultural and, human capitals are often complementary (Coleman,1993), emotional capital has a particular place among them. It is first a catalyser as it is essential for the constitution of the human capital. Indeed, human capital constitution might never happen if basic or appropriate emotional capital is not there. Only ad hoc emotional capital will allow human capital formation. Also, emotional capital is a potentionalizing - boostering- capital more than a simple additional capital as it is essential for utilizing effectively the social capital and the Becker Human capital (the way it has been restrictedly measured as general knowledge and technical skills). EK is a crucial capital as it impacts people's learning processes, especially for children and young people at risk, enables balanced human development, which participates in social cohesion, smoother human relationships, future successful life in the society and already to their school retention and success and as well as at work. In the work context, it improves the performance and well-being at work and especially when the managers have developed themselves the adhoc emotional capital to be mindful and benevolent manager (Gendron et al. 2008)  (Gendron, 2015) 
PsyCap has positive correlation with desired employee attitudes, behaviors and performance.
A meta-analysis of 51 independent samples found strong, significant, positive relationship between PsyCap and desirable attitudes (e.g., satisfaction, commitment, and well-being), behaviors (e.g., citizenship) and performance (self, supervisor rated, and objective) and a negative relationship with undesirable attitudes (e.g., cynicism, stress, anxiety, and turnover intentions) and behaviors (e.g., deviance).
PsyCap mediates between supportive climate and employee performance - Psycap
PsyCap and positive supportive climate are necessary for human resources in order to achieve stable organizational growth. Supportive climate is defined as the total support that an employee receives from their coworkers, other departments and their supervisors which helps them with their job demands.
High PsyCap Employees supports effective organizational change
Organizational change is defined as a lack of fit with the environment which intensifies as a result of a gap between the organizational goals and its present outcomes. The employees have the responsibility to adjust and behave according to the new strategy dictated by the management, mostly with fewer resources. During change, different aspects of employees' PsyCap is put to the test - they have to learn new ways of behavior and be confident to do so, recover from the crisis, be motivated to cope efficiently and to believe in a better future. PsyCap and positive emotions are examples of how personal factors facilitate organizational change. Positive change is defined as every change that the organization undergoes for its own benefit and has more positive psychological and behavioral consequences than negative ones. The role of positive emotions is that they help workers cope with the organizational change by broadening their point of view, encourage open decision making and giving them essential vitality for their coping. This interaction means that PsyCap, through positive emotions, influences the worker's attitudes and behavior, which in turn, influences the organizational change.
PsyCap can be developed
PsyCap can be extended beyond work into other life domains such as relationships and health
Recent research has found that measures of "Relationship PsyCap" and "Health PsyCap" are related to both individual's respective satisfaction appraisals and desired objective outcomes such as time spent with family and friend in the cases of relationships and cholesterol and BMI in the case of health. When combined with work satisfaction, these three are related to overall well-being.
Now after almost a decade of theory building  and research, PsyCap is widely recognized throughout the world and is being applied in positive leadership  and human resource development and performance management programs in all types of organizations - businesses, health, education, military and athletics.