U.S. choice moms -- mothers by choice -- tend to be heterosexual, white, well-educated, age 35 and older and financially well-established, a researcher says. Linda Layne, a professor of anthropology at Rensselaer Polytechnic Institute and currently at Cambridge Center for Family Research in England has been comparing choice moms -- moms with no husband or boyfriend -- in America and England. About three-quarters of choice moms in the United States conceive using insemination with the sperm of an open-identity donor, who agrees that when a resulting child turns 18, he may contact the donor, but smaller numbers do so with a known donor or through adoption, Layne said. "In the United States, opposition to single motherhood by choice is very often framed in terms of religiously informed ideas of what makes a proper family," Layne said in a statement. Layne said that in England the critique appears to be centered around government spending. "The United Kingdom has much better social support for its citizens, including national health care, maternity leave, child benefit payments and public housing," Layne said. "Opponents say that women are having children to get these benefits … It's a ludicrous assertion, but it's one that I heard within the first week that I got here."