A joint family is a family that extends beyond the nuclear family, consisting of parents, aunts, uncles, and cousins, all living nearby or in the same household. An example is a married couple that lives with either the husband or the wife's parents. The family changes from immediate household to extended household.
In some circumstances, the extended family comes to live either with or in place of a member of the immediate family. These families include, in one household, near relatives in addition to an immediate family. An example would be an elderly parent who moves in with his or her children due to old age. In modern Western cultures dominated by immediate family constructs, the term has come to be used generically to refer to grandparents, uncles, aunts, and cousins, whether they live together within the same household or not. However, it may also refer to a family unit in which several generations live together within a single household. In some cultures, the term is used synonymously with consanguineous family.
In a stem family, a type of extended family, first presented by Frédéric Le Play, parents will live with one child and his or her spouse, as well as the children of both, while other children will leave the house or remain in it unmarried. The stem family is sometimes associated with inegalitarian inheritance practices, as in Japan and Korea, but the term has also been used in some contexts to describe a family type where parents live with a married child and his or her spouse and children, but the transfer of land and moveable property is more or less egalitarian, as in the case of traditional Romania, northeastern Thailand or Mesoamerican indigenous peoples. In these cases, the child who cares for the parents usually receives the house in addition to his or her own share of land and moveable property.
In an extended family, parents and their children's families may often live under a single roof. This type of joint family often includes multiple generations in the family. From culture to culture, the variance of the term may have different meanings. For instance, in India, the family is a patriarchal society, with the sons' families often staying in the same house.
In the joint family, the workload is shared among the members. The patriarch of the family (often the oldest male member) is the head of the household. Grandparents are usually involved in the raising process of the children along with guidance and education. Like any family unit the success and structure are dependent on the personalities of the individuals involved.
Amy Goyer, AARP multigenerational issues expert, said the most common multigenerational household is one with a grandparent as head of household and his adult children having moved in with their children, an arrangement usually spurred by the needs of one or both to combine resources and save money. The second most popular is a grandparent moving in with an adult child's family, usually for care-giving reasons. She noted that 2.5 million grandparents say they are responsible for the basic needs of the grandchild living with them.
The house often has a large reception area and a common kitchen. Each family has their own bedroom. The members of the household also look after each other when a member is ill.
It has often been presumed that extended family groups sharing a single household enjoy certain advantages, such as a greater sense of security and belonging due to sharing a wider pool of members to serve as resources during a crisis, and more role models to help perpetuate desired behavior and cultural values. However, even in cultures in which adults are expected to leave home after marriage to begin their own nuclear-based households, the extended family often forms an important support network offering similar advantages. Particularly in working-class communities, grown children tend to establish their own households within the same general area as their parents, aunts, uncles, and grandparents. These extended family members tend to gather often for family events and to feel responsible for helping and supporting one another, both emotionally and financially.
While contemporary families may be considered more mobile in general than in the past, sociologists find that this has not necessarily resulted in the disintegration of extended family networks. Rather, technological aids such as the Internet and social networking sites such as Facebook are now commonly used to retain contact and maintain these family ties.
Particularly in the case of single-parent households, it can be helpful for extended family members to share a single household in order to share the burden of meeting expenses. On the other hand, sharing a household can present a disadvantage depending on the sizes and number of families involved, particularly when only a few members shoulder most of the responsibility to meet expenses for the family's basic needs.
An estimated 49 million Americans (16.1% of the total population) live in homes comprising three or more generations, up from 42 million in 2000. This situation is similar in Western Europe. Another 34 percent live within a kilometer of their children. 
In many cultures, such as in those of many of the Asians, Middle Easterners, Africans, Eastern Europeans, Southern Europe, indigenous Latin Americans and Pacific Islanders, extended families are the basic family unit. Even in Western Europe, extended families (mostly of the stem type) were also clearly prevalent, England being a rare exception. Some have stated that the relative "uniqueness" of the traditional English family (the absolute nuclear family) was at least partly responsible for the birth of industrialization, free-market capitalism and liberalism in that country.
It is common for today's world to have older children in nuclear families to reach walking up to driving age ranges before meeting extended family members. Geographical isolation is common for middle-class families who move based on occupational opportunities while family branches "retain [their] basic independence". Some extended families hold family reunions or opportunities for gathering regularly, normally around holiday time frames, to reestablish and integrate a stronger family connection. This allows individual nuclear families to connect with extended family members.
Australian Aborigines are another group for whom the concept of family extends well beyond the nuclear model. Aboriginal immediate families include aunts, uncles and a number of other relatives who would be considered "distant relations" in the context of the nuclear family. Aboriginal families have strict social rules regarding whom they can marry. Their family structure incorporates a shared responsibility for all tasks.
Where families consist of multiple generations living together, the family is usually headed by the oldest man. More often than not, it consists of grandparents, their sons and their sons' families.Extend families make discussions together and solve a problem.
Historically, for generations South Asia had a prevailing tradition of the joint family system or undivided family. Joint family system is an extended family arrangement prevalent throughout the Indian subcontinent, particularly in India, consisting of many generations living in the same home, all bound by the common relationship. A patrilineal joint family consists of an older man and his wife, his sons and unmarried daughters, his sons’ wives and children. The family is headed by a patriarch, usually the oldest male, who makes decisions on economic and social matters on behalf of the entire family. The patriarch's wife generally exerts control over the household, minor religious practices and often wields considerable influence in domestic matters. Family income flows into a common pool, from which resources are drawn to meet the needs of all members, which are regulated by the heads of the family. However, with urbanisation and economic development, India has witnessed a break up of traditional joint family into more nuclear-like families and the traditional joint family in India accounted for a small percent of Indian households.
In the early stages of the twentieth century, it was not very common to find many families with extended kin in their household, which may have been due to the idea that the young people in these times typically waited to establish themselves and start a household before they married and filled a home. As life expectancy becomes older and programs such as Social Security benefit the elderly, the old are now beginning to live longer than prior generations, which then may lead to generations mixing together. According to results of a study by Pew Research Center in 2010, approximately 50 million (nearly one in six) Americans, including rising numbers of seniors, live in households with at least two adult generations, and often three. It has become an ongoing trend for elderly generations to move in and live with their children, as they can give them support and help with everyday living. The main reasons cited for this shift are an increase in unemployment and slumped housing prices and arrival of new immigrants from Asian and South American countries. In 2003, the number of U.S. "family groups" where one or more subfamilies live in a household (e.g. a householder's daughter has a child. The mother-child is a subfamily) was 79 million. Two-point-six million of U.S. multigenerational family households in 2000 had a householder, the householder's children, and the householder's grandchildren. That's 65 percent of multigenerational family households in the U.S. So it is twice as common for a grandparent to be the householder than for adult children to bring parents into their home. The increase in the number of multigenerational households has created complex legal issues, such as who in the household has authority to consent to police searches of the family home or private bedrooms.
Mexican society is broken up into a three generational units consisting of grandparents, children and grandchildren. Further close relationships are maintained with the progenitors of these families and are known as kin or "cousins" When one is born they are born into two extended families, a kinship group of sometimes 70 people. The group traditionally acts as a cohesive unit pooling resources and influence. The extended family also consists of spouses and siblings. This is in contrast to the two generational American nuclear family.
Some scholars have used the term "grand-family" to describe the close relationship between grandparents, children, and grandchildren in Mexican society. Larissa A. Lomnitz and Marisol Perez-Lizaur, for example, describe the grand-family as "the basic unit of family solidarity in Mexico", where basic family obligations between grandparents, children, and grandchildren include "economic support, participation in family rituals, and social recognition". Katie Willis and Cathy Mcilwaine also note that grand-families are a "distinctive feature" of "low-income", "middle-income", as well as "elite sectors" of Mexican society.
Economic background has become a very prominent factor in the likelihood of living in an extended family. Many families who live in low-income areas are beginning to move in with one another for financial and emotional support. The relative economic deprivation of racial and ethnic minorities leads to higher levels of extended family involvement; primarily because blacks and Latinos have less money and education than whites, they are more likely to give and receive help from kin. Having family on which one can rely is very important in times of economic hardship especially if there are children involved. Living in an extended family provides constant care for children and support for other members of the family as well. Analysis of the National Survey of Families and Households suggests there are differences between whites and other ethnic groups because of economic differences among racial groups: blacks and Latinos less often have the economic resources that allow the kind of privatization that the nuclear family entails. Extended kinship, then, is a survival strategy in the face of economic difficulties. Being able to rely on not only two parents but grandparents, aunts, uncles, brothers, and sisters helps to create a support system which in turn brings families closer together. Living in an extended family provides many things that a nuclear family does not.
The number of multigenerational households has been steadily rising because of the economic hardships people are experiencing today. According to the AARP, multigenerational households have increased from 5 million in 2000 to 6.2 million in 2008."There's no question that with some ethnicities that are growing in America, it is more mainstream and traditional to have multigenerational households. We're going to see that increasing in the general population as well," says AARP's Ginzler. While high unemployment and housing foreclosures of the recession have played a key role in the trend, Pew Research Center exec VP and co-author of its multigenerational household study Paul Taylor said it has been growing over several decades, fueled by demographic and cultural shifts such as the rising number of immigrants and the rising average age of young-adult marriages. The importance of an extended family is one that many people may not realize, but having a support system and many forms of income may help people today because of the difficulties in finding a job and bringing in enough money.
"Complex family" is a generic term for any family structure involving more than two adults. The term can refer to any extended family, polyamorous or to a polygamy of any type. It is often used to refer to the group marriage form of polygamy.