According to Duckworth et all (2005), at that time, which of the statements below best describes the state of the field of positive psychology at the time they wrote their paper?
1) Although the field of psychology was not well-defined until recently, a great deal of research has already lead to many conclusive results, partly due to early researchers who were interested in positive psychology even before the field was promoted recently.
2) The field of positive psychology was early in development, with much more study and research needed before definitive conclusions could be reached in most cases.
3) Research and theory in positive psychology was well established, concepts and theories had been well defined, measured, and supported and findings were well developed.
4) While there were a few fruitful areas for new research, most of the field had been well-studied already.