Emotional change, regulation and expression have long played a crucial role in ethical programs, collective rituals, religious practices and moral narratives. Modern psychology, however, brought a radical transformation to the ways in which emotions are understood; the role assigned to them in shaping modern selfhood and sociability; the practices used to address, change and control them; and their moral horizon. The transformation modern psychology brought to the cultural models and practices by which we understand emotions and act upon them, is intertwined with yet another distinctive feature of twentieth-century society and economy. From its birth in the late nineteenth century, modern psychology worked to delineate the emotional as a distinct realm of intellectual and scientific observation, and a new site for professional practice in which money payment is an integral part. Freud's approach was soon contested by critics who demanded to be shown hard empirical statistical evidence.