I have been privileged to contribute to several distinct topic areas in personality, social, health, and abnormal psychology. Many of these contributions have had the label “self-regulation” attached to them at one time or another. To a personality psychologist (which is what I am), self-regulation refers to the use of mental reference points to guide one's behavior so as to create end states that correspond to those mental reference points.
My most important scientific contribution has probably been to help make this concept (and term) commonplace across psychology. At least two parts of that statement require more words. First, although I did play a role in popularizing self-regulation as a concept, I certainly didn't do it alone. Early in our careers, my collaborator Mike Scheier and I essentially caught a wave that was forming at the time. Our own contribution to the use of the term occurred in the context of that broader wave. (We did, however, spend an entire afternoon deliberating about using it in the title of our first book together.)
The second point that requires more words concerns the origins of the concept. Although I would be happy to avow my utter brilliance in synthesizing it, I did not do any such thing. Rather, having run across the concept in various guises early in my career, I decided that it mattered a great deal and that others should also realize it. So I tried over the years to make people aware of it and its relevance to the broader issues they were interested in.
There is a subtext here that students of psychology (and probably anything else) should realize. Almost everyone in any field, including psychology, would like to be widely known as the person who created some particular new idea (and, just as importantly, thought of a clever label for it). But ideas invariably have roots in other ideas. There are fewer new concepts than you probably think there are, but there are a lot of new twists on older concepts. I don't think I am entirely without creativity, but a startlingly high proportion of what I have done in my career turns out to have involved taking concepts others had created and applying them in slightly different ways to slightly different contexts.