While Wright, Wilson, and Anderson each position the underclass in reference to the labor market, Auletta's definition is simply "non-assimilation" and his examples, along with Mead's definition, highlight underclass members' participation in deviant behavior and their adoption of an antisocial outlook on life. These controversies are elaborated further in the next section ("Characteristics of the Underclass"). As evident with Mead and Auletta's framing, some definitions of the underclass significantly diverge from the initial notion of an "economic group" beneath the working class. A few writings on the underclass distinguish between various types of underclass, such as the social underclass, the impoverished underclass, the reproductive underclass, the educational underclass, the violent underclass, and the criminal underclass, with some expected horizontal mobility between these groups. Even more divergent from the initial notion of an underclass are the recent journalistic accounts of a so-called "genetic underclass", referring to a genetic inheritance of a predisposition to addiction and other personality traits traditionally associated with behavioral definitions of the underclass. However, such distinctions between criminal, social, impoverished, and other specified underclass terms still refer to the same general group—those beneath the working class. And, despite recent journalistic accounts of a "genetic underclass", the underclass concept is primarily, and has traditionally been, a social science term. The underclass is located by a collection of identifying characteristics, such as high levels of joblessness, out-of-wedlock births, female-headed households, crime, violence, substance abuse, and high school dropout rates. The underclass harbors these traits to a greater degree than the general population, and other classes more specifically. Joel Rogers and James Wright identify four general themes by which these characteristics are organized within academic and journalistic accounts of the underclass: economic, social-psychological, behavioral, and ecological (spatial concentration). The economic dimension is the most basic and least contested theme of the underclass – the underclass is overwhelmingly poor. The underclass experiences high levels of joblessness, and what little employment its members hold in the formal economy is best described as precarious labor. However, it is important to note that simply being poor is not synonymous with being part of the underclass. The underclass is "persistently poor" and, for most definitions, the underclass live in areas of concentrated poverty. Some scholars, such as Ricketts and Sawhill, argue that being poor is not a requirement for underclass membership, and thus there are individuals who are non-poor members of the underclass because they live in "underclass areas" and embody other characteristics of the underclass, such as being violent, criminal, and anti-social (e.g., gang leaders).