Meaning: Multiple partner fertility defined as having children with more than one partner.
When Dorius examined patterns in families with more than two children, she discovered that 28% of them had different birth fathers. "It's pervasive.", Dorius added.
Dorius and team gathered data from almost 4,000 women who had been interviewed face-to-face several times over nearly three decades. First interviews took place in 1979 when participants were aged between 14 and 22 years. Data was gathered regarding their education, employment, ethnicity, family characteristics, and custody status.
Dorius said that having multiple fathers had consequences for both the children and the mothers - they tend to be disadvantaged compared to other mothers in the country. A mother whose children had different biological fathers tends to spend approximately three times longer in poverty during adulthood, and had about 1 to 2 years less formal education than other females.
Because of the greater number of variables for both the mother and the children, Darius said this type of family structure tends to be more stressful.
"Everyday decisions are more complex and family rules are more ambiguous. Families need to figure out who lives with whom and when, who pays for things like clothing, who is responsible for child support."
This is the only study to look at a wide section of the community. Previous ones concentrated on very young mothers or those located in inner-cities.
Although a considerable number of such families have lower incomes, they exist in every socioeconomic level. 43% of women who have children from more than one biological father were married when they had their first child.
"What is unique about the data is that I found that women of all levels of education, income, and employment have children with more than one man."
The study revealed that:
- 22% of Caucasian mothers have had children with more than one father
- 35% of Hispanic mothers have had children with more than one father
- 59% of Afrcian-American women have had children with more than one father
"While these women tended to be poorer than others to begin with, their whole lifetimes continue to be disadvantaged"
It appears that young women are more likely today to opt for motherhood before even considering marriage. As this trend is fairly recent, nobody really knows what effect it may have on the mothers and the children.
The figures in this study show a much higher incidence of mothers with children with different birth fathers than previous studies - it should be more accurate because it lasted much longer.
Source: Population Association of America annual meeting, April 1, 2011, Washington, D.C.