Jonas is a work and organizational psychologist and has from early on in his career developed keen interest in accurately measuring what nobody can see ‒ psychological and organizational characteristics like engagement, motivation, skills, or abilities. He has published more than 60 papers in leading academic journals including many articles on psychological and organizational measurement. Jonas has also worked as an Associate Editor for the American Psychological Association's Journal of Applied Psychology. He has also won the Jeanneret Award for Excellence in the Study of Individual or Group Assessment from the Society of Industrial and Organizational Psychology. Jonas is a work and organizational psychologist and has from early on in his career developed keen interest in accurately measuring what nobody can see ‒ psychological and organizational characteristics like engagement, motivation, skills, or abilities. He has published more than 60 papers in leading academic journals including many articles on psychological and organizational measurement. Jonas has also worked as an Associate Editor for the American Psychological Association's Journal of Applied Psychology. He has also won the Jeanneret Award for Excellence in the Study of Individual or Group Assessment from the Society of Industrial and Organizational Psychology.