In line with previous work (Mancini and Bonanno, 2009), we adopt a definition of resilience as the maintenance or quick recovery of mental health during or after periods of adversity, whether they are traumatic events, challenging life circumstances, a physical illness or other types of stressors. In other words: resilience means to not develop, or only temporarily develop, mental problems despite significant psychological or physical burdens.
The key feature of this definition is that resilience is not a static property of the individual or a personality or character trait. Resilience research so far has found little evidence for individual properties that allow for predicting with acceptable certainty whether someone will go through challenging times without being much affected. Whether someone stays healthy can only be stated after those times are over. By contrast, there is more and more evidence that people change while they deal with adversity; in some people, this can take the form of a psychological maturation or growth process. Adaptive changes have also be observed at the level of gene expression. So, rather than being a fixed personality trait, resilience is the outcome of a process of successfully dealing with or adapting to stressors. Resilience can only be measured “ex post facto“ (Mancini and Bonanno, 2009).
Another key feature of the definition is that the outcome we are interested in when talking about resilience is mental health. We consider other outcomes such as maintained physical health, life satisfaction, quality of life, happiness, academic or economic success, social status, etc. as interesting and worthy objects of investigation, but we feel that resilience research would lose focus and clarity by incorporating any of these outcomes in the definition of resilience.
Thus, resilience is the result of a dynamic process of adaptation in which some people may stay mentally stable at any time point of stressor exposure or afterwards, while others may have temporary troubles but get back to normal functioning soon. We are interested in the mechanisms of adaptation that permit these positive mental health trajectories.
In the interest of finding resilience mechanisms – many of which have probably not been discovered yet -, we need to be open-minded. Our definition of resilience permits unbiased research as it does not include any presumptions about what those resilience mechanisms might be. It is atheoretical and therefore distinct from alternative definitions that are based on how people cope with stressors, experience the world, regulate their emotions, or interact with other people etc. The third key feature of our definition, therefore, is its atheoretical nature. We hope that this will permit researchers with different mechanistic theories to unite behind this definition and to evaluate their theories in a common effort with this community.