Kalisch et al. conceptualize resilience as resistance to adverse outcomes during and after experiences of threat (for greater differentiation concerning resilience as a concept, see Carver Reference Carver1998). They seek to identify a mechanism underlying resilience, as opposed to developing a list of variables that are associated with resilience. That is, although resilience is affected by many situational variables and individual difference variables, it almost certainly reflects functions that are fewer in number than the many variables that influence those functions.

Consistent with many other people, Kalisch et al. treat stress as being a product of a subjective appraisal of the likelihood and intensity of a bad outcome in a given situation, either acute or chronic. Further, they note that given the perception that an adverse outcome is likely, the more important the outcome is, the greater is the resulting stress (cf. Carver Reference Carver1998; Carver & Scheier Reference Carver and Scheier1998, Ch. 13, 16). This is all very consonant with many existing theories.

The core of the target article is Kalisch et al.'s assertion that the key to resilience is a tendency to make relatively positive appraisals of potentially threatening stimuli (sect. 4.2.1). Positive appraisals result in less emotional distress, less hypothalamus-pituitary-adrenal (HPA) activity, and more productive coping of various sorts. Kalisch et al. put it succinctly: “If a person has a tendency to see things negatively, she will more frequently be in a negative emotional state, and therefore more likely develop stress-related dysfunctions” (sect. 4.2.2). We regard that as a very reasonable assertion (Carver & Scheier Reference Carver and Scheier1998).

In our view, although Kalisch et al. never used the word expectancy, a large share of what they describe as “appraisal style” – maybe all of it, actually – appears to be captured by the concept of generalized expectancies for good versus bad outcomes. Equating the appraisals they discuss with expectancies regarding outcomes would link the appraisals directly to motivational processes (expectancy-value models of motivation have had a long history in psychology). This link to expectancies would account nicely for the emotional effects (and consequent HPA effects) that reflect resilience, and also for the coping effects associated with resilience (for a broader discussion of expectancy-value motivational ideas in the context of stress, see Carver Reference Carver, Friedman and Silver2007). Kalisch et al. also emphasize that it is desirable to think in terms of generalized appraisal tendencies – “the typical way in which [people] react to challenge” (sect. 4.2.2) – because a generalized tendency will pertain to reactions across a wide variety of stressors, rather than just a few.

From this point of view, then, the key to resilience would be generalized appraisals for positive versus negative outcomes from ongoing or upcoming life experiences. Confidence about outcomes would, in several respects, foster better results. Such a mechanism has a good deal to recommend it. Is it new? Are any existing constructs based on a similar mechanism? No, it is not new; and yes, there is a construct predicated on such a mechanism. It is termed optimism (Scheier & Carver Reference Scheier and Carver1985). It is based explicitly on the mechanism of generalized expectancies concerning life outcomes as an influence on diverse aspects of behavior. Over a period of nearly 30 years, it has been studied quite a lot, in relation to a great many emotional, coping, adaptational, and health outcomes (for reviews of various aspects of that literature, see, e.g., Boehm & Kubzansky Reference Boehm and Kubzansky2012; Carver & Scheier Reference Carver and Scheier2014; Carver et al. Reference Carver, Scheier and Segerstrom2010; Rasmussen et al. Reference Rasmussen, Scheier and Greenhouse2009; Segerstrom Reference Segerstrom2006).

Consistent with the reasoning that Kalisch et al. presented, but apparently completely unknown to them, a great deal of research has already shown that generalized optimism is associated with better emotional outcomes during stressful situations, more adaptive profiles of coping with adversity, better adherence to health-promoting behaviors, lower frequencies of health-damaging behaviors, better life attainments, better social relations, and even better physical health (in several respects) over extended periods of time (Carver & Scheier Reference Carver and Scheier2014; Carver et al. Reference Carver, Scheier and Segerstrom2010). Unfortunately, this considerable literature on the effects of generalized outcome expectancies was apparently unknown to either the authors or the reviewers of the target article.

This situation is unfortunate, and it illustrates a broader issue. A potential pitfall of multidisciplinary work, or of work that extends one discipline into a topic area that has been well explored by another discipline, is neglecting to consider the various constituencies and failing to review what they have already said. The target article clearly was more grounded in neuroscience and animal research than in human behavioral research and theory, and the failure to thoroughly examine the latter is a serious weakness.

Nonetheless, Kalisch et al. do add to the conceptual conversation. They emphasize that the appraisal processes are not fully conscious, and that they are fluid in operation (we agree with both points; these are ideas that, to our knowledge, have not been widely examined, and they should be). Kalisch et al. appear to be more interested in the neural circuits that support appraisal than in the subjective experience of appraisal, which presumably reflects their background in neuroscience. To their credit, they appropriately acknowledge that there often is a good deal of ambiguity about the meaning of neural activation (sect. 4.3.2). That is, in this case, there is ambiguity (among other ambiguities) about whether neural activation reflects appraisal contents or processes.

We are not as sanguine as they are about the prospects of gaining useful information about positive appraisals from neuroscience research or from animal research. But it is probably wisest to let a hundred flowers bloom and see what emerges. After all, it is widely known that positive appraisals are generally better than negative ones.