Over his career, Nesselroade served on the faculty of three universities,
West Virginia University (1967–1972),
Pennsylvania State University (1972–1991) and
University of Virginia (1991–2011). Until his retirement in 2011, he was the
Hugh Scott Hamilton Professor of Psychology in the Department of Psychology at the University of Virginia. He retained this title with an emeritus designation after his retirement. In 1970, while still at West Virginia University, he published his first article with
Paul Baltes, a German developmental psychologist, who was also on the West Virginia University faculty. This was just the first article of more than a dozen with Baltes on issues of change over the lifecourse. In 1972 both Nesselroade and Baltes moved to the College of Human Development at Penn State. Until Baltes left Penn State for Germany in 1980, they jointly contributed to the literatures on the development of personality and cognitive abilities, as well as to basic methods for measuring change. In publications with Baltes and others, Nesselroade promoted a comprehensive view of variability over people, occasions and psychological constructs. He distinguished between intraindividual variability, intraindividual change, interindividual differences and nuisance error variability. Examples of the first were states and moods that can fluctuate over short periods of time, whereas the examples of the second are longer-term development and growth that tend not to reverse. The third, interindividual differences, encompasses both differences in traits and differences in dynamic processes that regulate intraindividual variability and change. In addition to these systematic sources of variance, Nesselroade recognized that nuisance error variance needed to be recognized and minimized by careful measurement and latent variable modeling. In contrast to traditional developmental psychology, which described groups of people at supposedly different developmental stages, Nesselroade emphasized a focus on individual persons. In collaboration with his students and colleagues, he made contributions to dynamic factor analysis of intraindividual variability, dynamic oscillatory processes and latent difference scores. ==Controversy==