The interpretation of single individuals' measurements

The Central Role of the Concept of Person in Psychological Science

The first article in the present issue of JPOR is written by two pioneers in person-oriented research, John Nesselroade and Peter Molenaar. Among other things they argue that the individual is the primary unit of analysis for studying behaviour, and that this is in line with a growing emphasis on personalized diagnoses and treatment regimens in medicine, which reflects a renewed emphasis on focusing on the individual person. As was argued by Julia Moeller in a previous article in JPOR, however, psychological science seems to “lag behind” in this respect, with a concomitant risk of a credibility loss. One problem is that psychology still lack a coherent theoretical paradigm that places the person at the center of the stage. Some promising theoretical work on the concept of person has been carried out by researchers such as Mark Bickhard and Peter Ossorio, and it is possible that the future will see an increased cross-fertilization between (1) the theoretical development of a comprehensive model of the person and (2) methodological developments that facilitate the study of developmental processes at the level of the individual person.