Complex sentence: He formerly was Professor of Psychology and Provost at Oklahoma State University, Dean of Arts and Sciences at Tufts University, IBM Professor of Psychology and Education at Yale University, and the President of the American Psychological Association.
Split into simpler sentences: He formerly was Professor of Psychology and Provost at Oklahoma State University. He was formerly the Dean of Arts and Sciences at Tufts University, IBM Professor of Psychology and Education at Yale University, and the President of the American Psychological Association.