Gaja Zager Kocjan graduated from the Department of Psychology at the Faculty of Arts, University of Ljubljana in 2012, and received her Ph.D. in personality psychology from the same department in 2016. She was first habilitated as a teaching assistant in 2012. In 2018, she was awarded the title of assistant professor of general psychology, and in 2024, she was appointed associate professor of general psychology. Her research interests span the domains of subjective well-being and mental health, exploring their determinants ranging from stable personality traits to situational influences. She is interested in the role that stable interpersonal differences play in everyday functioning. More recently, she has focused on dynamic aspects of personality, i.e. understanding within-person fluctuations in momentary expressions of personality in different situations over time. She has been a Co-Editor of the Journal of Happiness Studies since 2023. She is also the principal investigator of the ARIS project "Long-term covida as a legacy of the pandemic: psychological symptoms, psychosocial factors and consequences" (J5-4591).