After obtaining her master’s degree in social psychology at the University of Helsinki, Finland, in 2004, Nelli worked in teaching and curriculum planning (e. g. University of Helsinki, Helsinki School of Economics, Open University) as well as a trainer for job search skills. In 2006, she began her doctoral research at the National Public Health Institute of Finland (currently National Institute for Health and Welfare, THL). Her PhD thesis focused on predictors of change in physical activity and diet in the GOAL Lifestyle Implementation Trial, an evidence- and theory-based diabetes prevention programme carried out in health care centres. During her PhD studies, she worked as visiting researcher at the University of Konstanz in 2008, collaborated with other research projects and coauthored a introductory textbook in social psychology. During her three-year post as Postdoctoral Researcher at the University of Helsinki, Social Psychology Unit in 2012-14, Nelli also worked at the University of Cambridge as Visiting Postdoctoral Research Fellow during the academic year 2012-13. In 2015, she moved to University of Tampere to work as University Lecturer in Social Psychology. She was granted Research Fellowship by the Academy of Finland for 2015-20. In 2017, she was appointed Assistant Professor (tenure track) at the University of Helsinki (teaching in Swedish), but gave up that position for a Full Professorship in Social Psychology at Tampere University in 2021. Her current work focuses on investigating uses of social and behavioural sciences in public policy, motivational and de-motivating interaction, and mechanisms of motivation and behaviour change in various applied areas.