Virtually all human individual differences have been shown to be moderately heritable. Much of this research, however, focuses on measures of dysfunctional behavior and relatively fewer studies have focused on positive traits. The values in action (VIA) project is a comprehensive and ambitious classification of 24 positive traits, also known as character strengths (Peterson, C., & Seligman, M. E. P. (2004). Character strengths and virtues: A handbook and classification. Washington, DC: American Psychological Association), the majority of which have received no behavior genetic attention. Using a sample of 336 middle-aged twins drawn from the Minnesota Twin Registry who completed the VIA inventory of strengths, we detected significant genetic and non-shared environmental effects for 21 of 24 character strengths with little evidence of shared environmental contributions. Associations with a previously administered measure of normal personality found moderate phenotypic overlap and that genetic influences on personality traits could account for most, but not all, of the heritable variance in character strengths.