Zak graduated with degrees in mathematics and economics from San Diego State University before acquiring a PhD in Economics from the University of Pennsylvania. He is professor at Claremont Graduate University in Southern California. He has studied brain imaging, and was among the first to identify the role of oxytocin in mediating trusting behaviors between unacquainted humans. Zak directs the Center for Neuroeconomics Studies at Claremont Graduate University and is a member of the Neurology Department at Loma Linda University Medical Center. He edited "Moral Markets: The Critical Role of Values in the Economy" (Princeton University Press, 2008). His book, "The Moral Molecule" was published in 2012 by Dutton. The book summarizes his findings on oxytocin and discusses the role of oxytocin in human experiences and behaviors such as empathy, altruism, and morality.