For example, through the use of cross-fostering designs, we can learn how genetically-related siblings reared apart in separate home environments may or may not develop the same disorders, and which aspects of their respective rearing environments are linked to these differences. The IVF design can help identify whether an environmental correlate (e.g., maternal smoking) of child behavior problems is present because of a child’s prenatal exposure, postnatal exposure, or both. And the parent-offspring adoption design can separate genetic and prenatal risks from postnatal risks on this same child phenotype. Together, these designs can increase our understanding how inherited characteristics of an individual can affect the extent to which a specific therapy or intervention related to the prevention of psychopathology is beneficial.
