This chapter begins with a brief review of the history of virtue science. It went out of favor in psychology for most of the twentieth century, but after renewed interest in philosophy in the latter part of that century, virtue research has burgeoned in psychology in the twenty-first century. The interest in virtue research is partly due to the positive psychology movement, which focuses on human strengths and well-being. Despite its valuable contribution, three elements of positive psychology have continued to plague virtue research as it is atheoretical, conceptualized as a diagnostic scheme, and ambivalent about values and morality. Nevertheless, virtue science is off to a good beginning, boasting scores of empirical studies. Most virtue scientists have left the ill-conceived notion of “diagnosing” virtues behind. These studies remain siloed and noncumulative due to the absence of clear theory in virtue science and a tendency to neglect conceptualizing virtues. Virtue research also remains limited by its ambivalence toward values and morality. To remedy this fragmentation, this chapter proposes the STRIVE-4 Model, with its clear conceptualization of virtues and the dozens of hypotheses that follow from it. This model provides a way to build a unified and cumulative virtue science.

This chapter begins an in-depth discussion of the proposed STRIVE-4 Model. It focuses on the S (scalar) and T (trait) of the model. To demonstrate that virtues can be captured in a scalar manner, It highlights studies that support the reliability and validity of constructs. Virtues such as courage, gratitude, and compassion have all been established as scalar constructs and have been related to a variety of expected well-being outcomes. The chapter further highlights empirical evidence showing that virtues cannot be subsumed by personality research or social desirability, and that informant reports further confirm researchers’ ability to capture scalar virtues. To highlight empirical work on virtues as traits, it discusses the value of intensive longitudinal studies. These studies demonstrate between-person variability and within-person consistency to support the hypothesis that virtues are traits. Finally, the chapter closes by discussing some challenges of virtue assessment, including Aristotle’s assertion of the golden mean and how to understand vice traits. Altogether, the evidence favors assessing virtues as scalar traits. It suggests it is time for researchers to advance virtue science with more sophisticated methods.