Genetic effects may in part be mediated through biological factors that are beginning to be identified as shared risks for oppositionality and conduct problems (Beauchaine, Gatzke-Kopp, & Mead, 2007). However, such biological factors are likely to interact in complex ways both among themselves and with environmental risks (e.g., Rowe, Maughan, Worthman, Costello, & Angold, 2004). Much more must be learned about these effects before they can contribute to diagnostic formulations (Moffitt et al., 2008).
