ABSTRACT
The metaphor of having to fit hundreds of pieces together to make a jigsaw puzzle is a good one for writing this synthesis of results. In the picture on the jigsaw puzzle, models for individual differences have come up as dominant figures and helped to fill in the details of the picture. As noted by Stikker (2012), a model is not the same as reality, but it is a simplified picture invented by a researcher, a schematic representation of a phenomenon. Although a model is never complete, it may satisfy a researcher’s desire to discover order in the structure and dynamics of a phenomenon.
