Jan Strelau: Two perspectives

We discuss the life and work of Jan Strelau from the perspectives of the Regulative Theory of Temperament and Five-Factor Theory. Both posit that traits are early-appearing and relatively stable over time, have a substantial biological basis, can be found in human and non-human species, and must be inferred from the behaviors that express them; they differ in the scope of temperament, the role of the environment in shaping traits, and the adaptive function of traits. The instruments associated with the two theories converge empirically: The temperament traits of Briskness and Endurance are related to Conscientiousness, Perseveration and Emotional reactivity to Neuroticism, Activity to Extraversion, and Sensory sensitivity to Openness. Five informant ratings of Strelau concurred in showing that he was low in Neuroticism and high in Extraversion, Openness, and Conscientiousness. A biographical sketch shows that despite potentially traumatic events in childhood and adolescence, Strelau lived a full and productive life. His life course is consistent with the view of both theories that adult personality traits are chiefly a reflection of biological influences.