Virtual twins are children who are raised together, but have no genetic relationship. They are also very close to each in age, generally less than nine months apart in age. They can come into a family in a wide variety of ways, and they are a topic of interest to psychologists and other researchers, as they can be used to delve into the relationship between environment and genetics.
In a classic example of virtual twinning, a couple makes arrangements to adopt after struggling to have children, and then becomes pregnant. Rather than backing out of the adoption, the parents may choose to adopt as well as giving birth, giving their birth-child an adopted sibling. Virtual twins can also be created through adoption, with parents adopting two children of different parentage. Many researchers like to focus specifically on virtual twins adopted at a very young age, rather than older children adopted together.
For people interested in the nature vs. nurture argument, virtual twins can provide some interesting food for thought. Researchers who believe that environment plays a larger role than genetics would expect these twins to be very similar, since they are raised in the same environment. Studies suggest that they have fewer similarities than true genetic siblings, however, which suggests that genetics plays a heavy role in human development.
Life for virtual twins can be interesting. In the case of twins who resemble the people raising them, people may be confused about how they were born, which can sometimes be awkward in the case of a situation where one twin is adopted and one twin was born into the family. Children of a different racial background obviously stand out as adopted, although parents who adopt children of the same ethnicity may be asked if the twins are from the same family by people who are curious, and this can sometimes become irritating.
Parents who believe that siblings play a valuable role in the development of their children may deliberately set out to adopt virtual twins. Parents participating in transcultural adoption may also choose to adopt virtual twins so that their adopted children have a familiar face to interact with, in the hopes of making their children feel less alienated by the foreign culture into which they are adopted. Others may choose to adopt children of radically different ethnicities, for a variety of reasons.