Over 50% of adoptions are transracial, involving primarily White parents and children of color from different ethnic or racial backgrounds. Transracial adoptive (TRA) parents are tasked with providing ethnic–racial socialization processes (ERS) to support TRA adoptees’ ethnic–racial identity development and prepare them to cope with ethnic–racial discrimination. However, unlike nonadoptive families of color, TRA parents lack shared cultural history with adoptees and have limited experience navigating racial discrimination. Knowledge of ERS among TRA families has centered on unidirectional processes between parenting constructs, ERS processes, and children's functioning. However, ERS processes in this population have complexities and nuances that warrant more sensitive and robust conceptualization. This paper proposes a process-oriented dynamic ecological model of the system of ERS, situating transacting processes in and across multiple family levels (parent, adoptee, family) and incorporating developmental and contextual considerations. With its framing of the complexities in ERS among TRA families, the model offers three contributions: a conceptual organization of parenting constructs related to ERS, a more robust understanding of ERS processes that inform how parents provide ERS, and framing of transacting processes within and between parenting constructs, ERS processes, and children's functioning. Implications for research, policy, and practice are discussed.

Virtual twins (VTs) are defined as same-age unrelated siblings raised together from early infancy. This special class of adoptive siblings replays the rearing situation of twins, absent genetic relatedness. The first such pair was identified and studied in 1990 at the University of Minnesota, leading to the creation of the Fullerton Virtual Twin Study (FVTS) at California State University, Fullerton (CSUF) the following year. The registry currently includes 169 VT pairs, mostly children, with new pairs identified on a regular basis. These sibling sets provide a direct estimate of environmental influences on developmental traits and, as such, offer informative comparisons with ordinary monozygotic and dizygotic twins, full siblings and adoptive brothers and sisters. The sample characteristics, assessment battery and findings to date are summarized in this 2019 update.

Ronald Wilson presented the first clear and compelling evidence that the heritability of IQ increases with age. We propose to call the phenomenon ‘The Wilson Effect’ and we document the effect diagrammatically with key twin and adoption studies, including twins reared apart, that have been carried out at various ages and in a large number of different settings. The results show that the heritability of IQ reaches an asymptote at about 0.80 at 18–20 years of age and continuing at that level well into adulthood. In the aggregate, the studies also confirm that shared environmental influence decreases across age, approximating about 0.10 at 18–20 years of age and continuing at that level into adulthood. These conclusions apply to the Westernized industrial democracies in which most of the studies have been carried out.

Virtual twins (VTs) are same-age unrelated siblings reared together from early infancy. These unique sibling sets replicate twinship, but without the genetic link. The first VT pair was identified and studied at the University of Minnesota in 1990, launching the development of the Fullerton Virtual Twin Study at California State University, Fullerton (CSUF) in 1991. The registry currently includes 151 pairs, mostly children, with new pairs identified on a continuous basis. Research with VTs includes studies of general intelligence, body size, interpersonal trust, social coordination, social networks, and parenting. In some cases, VTs have been studied in conjunction with pairs of monozygotic twins, dizygotic twins, full siblings, and friends as part of TAPS (Twins, Adoptees, Peers and Siblings), a collaborative project conducted between CSUF and the University of San Francisco, 2002–2006. VTs will also serve as a comparison group for epigenetic analyses of young Chinese twins reared apart and together.