ITHACA, N.Y. -- Is the American family dissolving or evolving, asked H. Elizabeth Peters, professor of policy analysis and management in the College of Human Ecology at Cornell University in a public lecture April 20. Her talk launched the upcoming year of Cornell events focused on the family.

"Well, the answer depends on your definition of family," said Peters. She is the theme leader for the first three-year initiative of the Institute for the Social Sciences (ISS) at Cornell, which was established in 2004 and chose the evolving family as its first theme project last summer.

The family has been undergoing dramatic changes over the past several decades, with high rates of divorce and increases in births to unmarried women resulting in increasing numbers of children living in single-parent households. How these trends affect child development and how public policies may impact children, families and marriage remains to be seen, Peters said.

Among the many trends that Peters reviewed was the percentage of children living in single-parent homes, which jumped to 28 percent in 2002 from 12 percent in 1970. Another trend in 2001: 69 percent of births to African-American women were outside of marriage, compared with 43 percent among Hispanic women and 23 percent among white women.

In addition, more women with young children are working: 58 percent of women with children under the age of 1 are in the labor force, including 78 percent of African-American women with children under the age of 1. Also, stepparent and unmarried-two-parent families are becoming increasingly common.

Peters pointed out that bearing children outside of marriage and raising children in one-parent households are linked to lower incomes. Research shows, she said, that income accounts for about half the difference in how children fare academically and in other ways in single-parent homes compared with children in two-parent households. Many children in homes headed by single mothers also tend to have little contact with their fathers.

"There are huge, huge differences across different race, ethnic and socio-economic groups in childbearing outside of marriage and in family structure," noted Peters. "We care about these trends because there are consequences of these changes in family structure for children."

Peters said these demographic shifts have prompted researchers at Cornell affiliated with the ISS evolving-family theme to focus on fatherhood and marriage. "We're looking at questions such as what influences the timing of biological fatherhood, and how do such factors impact marriage, residence in the household, education and income," said Peters. She pointed out that the researchers not only are looking at how race, ethnicity and social class influence marriage and fatherhood but also how the meaning of marriage and sexual partnerships has changed over the past 30 years and how these changes affect children. In addition they are looking at the parenting and partnership behaviors of birds and other animals and how they inform issues regarding marriage and fatherhood.

About a dozen eminent social scientists at Cornell from a range of disciplines, including anthropology, biology and evolutionary biology, demography, economics, government, human development, policy analysis, psychology, sociology and women's studies, are conducting collaborative research, sponsoring seminars and outreach activities, offering new courses and engaging students, faculty and staff in interdisciplinary discussions pertaining to the evolving family, worldwide.