The psychology of family examines how and why we have families and close relationships as also the dynamics of family interactions. The structure of families is based on evolutionary biology, anthropology, history and sociology and the roots of family systems are found within these disciplines. However studying family structure will show us how family systems have evolved over time but may not directly tell us why family relationships develop in the first place. Family relationships are in turn studied with psychology, child development and philosophy and suggest why family forms the basis of our existence. The interdisciplinary approach to the study of family will have psychology at its core as human evolutionary biology, sociology, philosophy have significant psychological components.
To begin an answer to the questions on how family structures have developed, early evolutionary history and anthropology will suggest that family , albeit in a different form is the basis of human civilization. The earliest men who lived in caves and forests, quickly formed groups or tribes to protect themselves from wild animals. Research into anthropological remains has shown the life of primitive humans who were cave dwellers. Forming herds was one of the basic security and safety needs of humans as by forming a large family they could attack or defend themselves against wild animals, warn each other of natural disasters, gather food and raise children in a community, almost like modern day societies. Thus the earliest families were tribes or herds and there were several generations of humans in one family. Family sizes were thus presumably large with entire forest tribes forming single families. However this tribal system of forming large communities possibly did not last long and some humans wanted a different kind of life and migrated to places where there were no communities or tribes. Some others may have simply weighed the disadvantages of a group life as insurmountable and reasons could be possible jealousy regarding mates, dissatisfaction in sharing food, shelter and apathy for the rules of a community life. The freedom seekers moved out of this community pattern and groups became smaller and humans started building their own homes and the first human civilization was thus laid with many smaller families, although large when compared with contemporary nuclear families of a couple and their children. The basic human need of safety and security gave way to the fulfilment of more emotional needs of love and sharing through family systems and humans developed attachment and affection as these were constantly reinforced with rewards of love, love making or promise of love.
Humans as we know were born with some basic drives of sex and aggression, as suggested by Freud but humans found that they could fulfil their sexual needs only when they also showed attachment and affection as attachment and affection were often rewarded with sex and through sex, their aggressive needs were also fulfilled to an extent. That is how humans developed attachment and affection and these positive emotions have been constantly rewarded and thus have been reinforced over time to the point that love in a civilized society has been glorified and sex has been degraded. Of course, psychoanalysis would suggest that love is just a sugar coating on our real primal sexual needs, the fact remains that humans have constantly found that indirect love needs are more readily rewarded than direct sexual needs and thus developed these positive emotions of love and attachment as the basis of family structures. Experiments by psychologist B. F. Skinner successfully showed that behaviors are reinforced when rewarded. Family systems are built on the foundation of love, attachment, loyalty, trust, which in turn fulfils safety and status needs and thus psychology is an important ingredient in family interactions.
The Psychology of Family Structures:
The psychology of family could possibly branch out to two directions on understanding how and why family structures have evolved in a specific way. Why did the earliest humans form tribes or groups and why did suddenly abandon the nomad life to begin farming and settled in homes? How did communities form and why were social rules made that helped to protect the family system? Why did the family size diminish over time? What needs were fulfilled with the changing family patterns? This branch of the psychology of family studies social systems, political systems, civilizations and history and evolutionary biology and anthropology. This is the structure of the family, the basic family systems and the psychological basis of the evolution of family. Here the basic social psychology of group behavior and group formation highlights the reasons of forming groups through cooperation (with other members) and identification (with the group) as found in earliest humans and continues to this day. Kurt Lewin, Bruce Tuckman and Gustav Le Bon are noted group behavior theorists in social psychology. Family formation could be explained with Maslow's hierarchy of needs as family provides the basic safety and security as well as love needs and in some cases also fulfils our status needs. I have discussed Maslow at length in another essay. The basic drives of sex and aggression being fulfilled through love and attachment as we get in families would be a Freudian explanation of family systems. Existentialism by Sartre who claimed that man is thrown alone in this world with an inherent sense of isolation could explain the need to overcome this loneliness. Group structure and group interaction are both explained with these varied theories.