This is the fourth in a series about 21st century families.

Q: What are additional changes in 21st century families?

A: One of the significant changes in families is the increasing number of same-sex couples who are pursuing parenthood. New research suggests former fears about the children of gay parents being stigmatized and lacking conventional adult role models were unfounded. Researcher Michael J. Rosenfeld from Stanford University found that whatever problems the children of gay parents display are more likely to come from the disruption of the heterosexual marriage that produced the children.

Once these factors of the effects of dissolved heterosexual families that produced the children with same-sex parents were taken into account, these children are emotionally and academically the same as children with heterosexual parents.

Two-father couples were the most stable in regard to domesticity. In long-term research of unconventional families, Judith Stacy, professor of social and cultural analysis at New York University, found the most stable of all families were those of gay men who had had their children together.

Stacy found that during a period of 14 years, none of the male couples with children had broken up. She attributed their success to self-selection. For men to become parents is difficult. Only a small percentage of gay men are willing and able to make that commitment.

According to research from the Williams Institute at the University of California, the number of gay couples who have children has doubled in the past decade. More than 100,000 same-sex couples are raising children. Other studies estimate the number of children living with gay couples or single gay parents is close to 2 million or one out of 37 children younger than 18 years.

Along with the increase in same-sex parenthood has come the legalization of same-sex marriages in 16 states and the availability of adoption for same-sex couples. From 2000 to 2009, the percentage of same-sex couples raising children went from 10 percent to 19 percent. Gay couples often care for foster children whom they later adopt. Many of the lesbian couples have children that are the offspring of one of the women. The sperm donor might be from a sperm bank or a friend or relative.

Some couples choose cohabitation over marriage because the thought of marriage is too intimidating. There are two changes in families that researchers designate as most significant. First is the increase in out-of-wedlock births among all but the most highly educated women. The second most important change in families is the repositioning of marriage from cornerstone to capstone. Marriage was a foundation act of early adulthood and changed to a crowning event in later adulthood. Marriage now follows achievements such as finishing college, beginning a career and furnishing a household.

The two trends are interrelated; according to researchers, more Americans are becoming intimidated by the idea of marriage. Its cultural status has changed from that of modestly optimistic beginners to that of the mark of established winners.

Childbearing happens naturally and offers lifelong relationships of love. Kelly Musick, associate professor of policy analysis and management at Cornell University, has studied cohabitation. She found cohabiting couples have high expectations for marriage, about where they should be emotionally and economically. If couples don’t meet their standards, they postpone marriage.

However, if couples are satisfied with their relationships and find themselves pregnant, they are happy to have a child even if they are not at a great place financially. Couples find a sense of fulfillment in parenthood even if the rest of their lives is not ideal.

Dr. Kathryn Edin, professor of public policy and management at Hopkins University and her colleague, Timothy J. Nelson, interviewed hundreds of low-income families. They describe the great instability in families among the working class and the poor.

Among middle-class families, the divorce rate has decreased, and life is less complicated, Edin stated. But among the poor, there is more complexity due to instability in households, turnovers in partners and many half-siblings.

However, Edin stated the young men of low-income whom she interviewed were eager to assume their paternity. They show up at hospitals to sign birth certificates. They are assuming this responsibility willingly even though they know signing their names on birth certificates makes them liable for child support.

According to Edin, these fathers continue to be involved in their children’s lives. Five years later, two-thirds of fathers continue to see their children at least monthly. A little less than half see their children several times weekly.

Kathryn Klement, Northern Illinois University doctoral candidate, surveyed 329 married Indian women. One hundred seventy-six of them were in arranged marriages. Klement found no differences between the two groups of arranged vs. non-arranged marriages. She compared happiness, feelings of intimacy, trust and commitment, sexual satisfaction and ease in expressing their desires. An Indian couple enumerated that tolerance is the key to lasting marital harmony. Tolerance also applies to parenting. They feel they have high expectations to try to seek ways for children to improve.

In a long-term study of 300 Chinese-American families, researchers led by Su Yeong Kim, associate professor of human development and family services at the University of Texas at Austin, determined which parents were most likely to raise high-achieving children. Kim found the most effective parenting was a combination of control with a high level of warmth. Supportive parenting produces the best outcome academically and emotionally.

A few years ago, the University of California-Los Angeles conducted an anthropological study of 32 typical middle-class families. Researchers focused on dual-income families with two or more school-age children living at home in the Los Angeles area. Researchers spent weeks observing each family, recording all aspects of each family.

Researchers learned American families stop just short of clinical, compulsive hoarding. American families own “more material goods per household than any society in history,” according to professor of anthropology and researcher Jeanne E. Arnold.

The study emphasized the central role of the kitchen, in which the largest and most visible clocks were displayed and where the most calendars, school memos and to-do lists were displayed. Researchers also discovered even when all family members were home and awake, they were in the same room only 14 percent of the time. The same researchers have done comparative studies of families in Sweden, Italy, Samoa and the Peruvian Amazon and found the American families are fixated on children’s needs and children’s successes.

In other societies, children are supposed to see what needs to be done without being told, according to Elinor Ochs, director of the study. In mainstream middle-class families in America, you can’t ask kids to do anything. The more educated the mother was, the more time the children spent in organized activities and homework.

• Next week’s discussion will continue regarding how 21st Century families are changing.

Judy Caprez is professor emeritus at Fort Hays State University.