The terms, father, mother, brother, sister, refer to certain positions in the family group. The sexual and social roles of husband and wife are often described as conjugal roles. The family takes many forms in society, most fundamental of which is the nuclear family (sometimes also called the conjugal family).
The structure of a traditional Nuclear family (so called perfect family), has to be made up of a father figure, mother figure and at least one child. This family structure can been seen in almost every society in the world, although the length and time a society will call themselves a family change. The featured first in Murdock's studies on family's he looked at 250. This even changes from different people in the same society different families will stay a family but not a nuclear family. In the IK tribe there Nuclear family ends at the child's 3-4th birthday. The nuclear family was most popular in the 1950-60's.
The nuclear family can be a nurturing environment in which to be able to raise a child there has to be love, time and emotional support. In a nuclear family the only rule is that both adults are the biological or at least the adoptive parents of their child or children. All sociologists agree on these points. They think its very important to have a family around you when you grow up.
The leading two sociologists that have carried out work on Nuclear families are Murdock and parsons. Murdock (1949) wanted to know if the family was not cultural but actually universal. He claimed that is was universal. He also believed the nuclear family was the universal core of the world's large variety of kinship systems. From this a family could be extended vertically (with upper generations.) or horizontally (with brothers and sisters). Therefore the nuclear family's growing all the time. Many sociologists however will criticise Murdock's work because it was based on readings of other tesxts rather than his own fieldwork.
In the 1950's...