In the Q&A below, Scheier reflects on his influential work with Carver and shares how their humble study on human motivation ultimately inspired countless studies on mind-body interactions. He also assesses why their optimism scale was an instant hit in the scientific community, how their findings have been adapted by other researchers, and the future of our understanding of hope and well-being.

How did the research come about?

Chuck Carver from the University of Miami and I were doing research on human motivation. We were trying to understand how to think about goal-directed behavior, and expectancies were an important part of our approach. The idea was, and still is, that when people encounter difficulties doing what it is that they intend to do, some sort of mental calculation takes place that results in the generation of an outcome expectancy -- the person's subjective assessment of the likelihood that he or she will succeed. We thought these expectancies played a role in the nature of the affect that was experienced and the person's subsequent behavior.

Initially, we considered outcome expectancies in a very circumscribed way. We focused on specific situations manipulated in controlled experimental contexts to validate our ideas. For example, we studied snake phobics who approached a boa constrictor in a cage. We weren't interested in snakes or phobias per se but in how these expectations drove behaviors.

At some point in the early 1980s, things changed. A number of our colleagues in health psychology -- my wife, Karen Matthews, included -- urged or maybe even challenged us to consider applying some of our ideas to real-world settings, particularly those that might be relevant to well-being. Our formal area of study in graduate school was also personality, and I started to hear the voice of my advisor, Arnie Buss, in my head gently pushing us to do what it was that we had been trained to do.

This confluence of events started us thinking about expectancies in a broader way that might be more reflective of stable expectancies for positive or negative things to occur. And voila! We found ourselves interested in dispositional optimism, which we define as the general expectation that good, versus bad, things will happen across important life domains.

What were your goals? Was there a research gap you were hoping to fill back then?

Once we knew what we wanted to study, we looked around the literature to see if there was a scale that assessed dispositional optimism that was consistent with how we viewed the construct. We couldn't find anything that was right on the mark, so we set out to make our own measure for dispositional optimism using a self-report questionnaire (PDF of updated version). Along with that came the job of establishing the statistical characteristics, or psychometric properties, of the scale. This became part of the purpose of our original paper too.