David Magnusson is known for several theoretical, methodological and empirical contributions to psychological science.
[2] The basic assumption is that each person is seen holistically, with multiple systems that interact with the environment in various unique ways.
[4] Magnusson is also known for his longitudinal study Individual Development and Adaptation (IDA),[5] which he started in the 1960s and led until 1996.
[6] This research program targeted two whole cohorts of school children in Örebro, Sweden.
After Magnusson's retirement, the IDA program was led by professor Lars R. Bergman, Stockholm University, and after Bergman's retirement by professors Henrik Andershed and Anna-Karin Andershed at Örebro University.