William Marelich is an applied quantitative social psychologist with research interests in health psychology, HIV/AIDS, decision-making strategies in health settings, intimate/close relationships, and statistical/methodological approaches in experimental and applied research with a specialization in longitudinal design and analysis. He received his BA and MA from California State University, Sacramento, a PhD from Claremont Graduate University, and a National Institute of Mental Health (NIMH) postdoctoral fellowship from University of California, Los Angeles (UCLA). Currently he is Professor of Psychology (California State University, Fullerton). His past appointments include Senior Statistician for Health Risk Reduction Projects (Integrative Substance Abuse Programs [ISAP], Department of Psychiatry and Behavioral Sciences, David Geffen School of Medicine at UCLA), research consultant for UCLA’s Neuropsychiatric Institute (NPI), Research Scientist on a project thru Pacific University to reduce childhood maltreatment and noncommunicable diseases in Kenya, Africa, and Research Analyst for the Office of AIDS (California Department of Health Services). He is a 2-time recipient of the prestigious Outstanding Scholarship and Creativity Award from the College of Humanities and Social Sciences, recently (2025) received a Dean’s Faculty Scholarly Achievement Award, been recognized 6-times by Academic Affairs for outstanding scholarship, and is a full member of Sigma Xi (the Scientific Research Honor Society). Dr. Marelich has over 90 peer-reviewed publications and monographs, and is author/coauthor of three books including Health Psychology: Alternative Topics, The Social Psychology of Health: Essays and Readings, and Advanced Statistics for Kinesiology and Exercise Science: A Practical Guide to ANOVA and Regression Analyses. He also has an interest in Sport Psychology with applications to baseball.