Unilinear cultural evolution is a phenomenon that describes the development of cultures from simpler basic forms to civilized societies. It is a late 19th century theory that explains evolution of all human societies to have occurred along a common line, from hunters and gatherers to complex civilized communities.
Unilinear evolution, also known as classical social evolution is a social theory about the evolution of human behaviors in its entirety. This theory was a significant concept in the field of anthropology. It envisages that various social statuses are aligned in a straight line that moves from the most uncivilized to the most complex. It states that because mankind was one in origin, their development has been the same upon all continents.
Human cultures evolved from simple species to the more complex beings, evolving by way of labor differentiation. In the early days of humanity, people lived in homogeneous groups, then social hierarchies emerged distinguishing individuals as kings, scholars and workers. Increasing accumulation of knowledge further differentiated people into different groups.
This theory lost favor among scholars upon the introduction of a divergent view, or multilinear cultural evolution at the beginning of 20th century. This shaped much of the subsequent research in the fields of anthropology and archaeology.