Recent years have witnessed a surge of management research on biology and affect (see Chapter 2 on the organizational neuroscience of emotions). An important reason is perhaps that management researchers have gradually realized the prominence of biological factors, including brain functions, hormones, and genetic factors, in modulating our attitudes and behaviors (e.g. Arvey, Li, & Wang, 2016; Arvey, Wang, Song, Li, & Day, 2014; Ashkanasy, Becker, & Waldman, 2014; Becker, Cropanzano, & Sanfey, 2011; Li, Stanek, Zhang, Ones, & McGue, 2016; Senior, Lee, & Butler, 2011; Waldman, Balthazard, & Peterson, 2011; Ward, Volk, & Becker, 2015). In this chapter, we will concentrate on the role of behavioral genetics and how this approach contributes to workplace affect. First, we will discuss the importance of behavioral genetics in fostering a more nuanced understanding of workplace affect. Second, we will review previous research, including both twin studies and molecular genetics research, on the influences of genetic factors on affect in the workplace, and we will selectively survey research on affect in general. Third, building upon recent research on behavioral genetics (Arvey & Bouchard, 1994; Arvey et al., 2016; Ilies, Arvey, & Bouchard, 2006; Li, Ilies, & Wang, 2017; Zyphur, Zhang, Barsky, & Li, 2013), affective events theory (AET) (Weiss & Beal, 2005; Weiss & Cropanzano, 1996), and personality development (Wrzus & Roberts, 2017), we will discuss an integral theoretical framework of workplace affect including influences from both genetic factors and environmental factors. We also offer some possible directions for future research.