The vast majority of children born from open-identity sperm donors feel positively about their conception and are simply curious about their genetic fathers, according to the first study of its kind developed by UC Davis psychologist Joanna Scheib.

Her study, conducted with Maura Riordan and Susan Rubin, uses data collected through The Sperm Bank of California in Berkeley. The adolescents, ages 12-17, were conceived by donors who allowed their identification to be given to their adult offspring at age 18.

The study is important because the first children conceived under open-identity conditions in the United States are now about 21 years old, Scheib says. A growing number of children conceived through this method will be coming of age in the near future.

"Parents are concerned about how their children will react when they learn they are not genetically related," Scheib says. "This feedback reassures us that the vast majority are curious but not really looking for a father in the donor. The youths are more likely looking for information that tells more about themselves."

Scheib, who also is director of research for the Berkeley-based sperm bank, reports that more than 30,000 children are born each year in the United States through donor insemination.

The children in the study, when told early about their origins, reacted similarly to how adopted children respond when they have been told about their adopted state from a young age: they incorporate it as a matter of fact, Scheib reports.

The study, which queried youths across the nation, found that most of the children first learned how they were conceived between the ages of 5 and 8, and all knew by age 10.

Scheib's study on open-identity sperm donors is being published Thursday in Human Reproduction, Europe's leading reproductive medicine journal.