Paulius is an alumnus of the PhD programme at the Department of Psychological and Behavioural Science, and is currently the Scientific Director at the Paris Institute for Advanced Study. 

He also works as a consultant on behavioural and social norm change for UN agencies (ILO, IOM), the World Bank, USAID, and other international organizations in several countries (including Colombia, Bosnia and Herzegovina, Ecuador, Perú, El Salvador, and others), and co-heads the Behavioural Science Working Group at the International Panel for Social Progress.

Paulius has been the Managing Director of the Center for Social Norms and Behavioral Dynamics at the University of Pennsylvania (US), co-founder and Managing Partner of the Behavioural Lab, creator and first Head of the first behavioural unit at the Colombian Government, and as Research Assistant for the former Mayor of Bogotá, Antanas Mockus.

His research focuses on behavioral and social norm interventions in different policy and international development challenges, including discrimination against migrants, civic engagement, violence and harassment, domestic work, transparency and public integrity, and organisational change, among others.