1. Part V: Social Change

2.  Demography is the scientific study of population.  Demographers look at many factors when studying population, including size of a population, distribution, age structure, fertility, mortality, and migration.  Sociologists study population because it affects social structure, especially in crowded areas.

3.  Rapid world population growth is a relatively recent phenomenon, but concern about population is not new.  English economist Thomas Malthus published essays on population growth in relation to economic development in the late 1700s. Some countries in the world have even experimented with voluntary as  The rate of world population growth is slowing, but because of population momentum, it will continue to increase for many years.

4.  The world has been greatly changed by urbanization, beginning with the Industrial Revolution.  In the early 1900s, the U.S. went through a process of urbanization as the population shifted from farms to manufacturing jobs in the city.  Today, however, suburbanization has become the dominant trend, enabled by technological and transportation developments and fueled by a scarcity of land in cities.

5.  Urban ecology is the study of the relationships between humans and their city environments.  Urban ecologists have developed four major theories of city growth — concentric zone theory, sector theory, multiple nuclei theory, and peripheral theory.  Combining elements from each theory is useful in understanding how humans relate to city environments.

6.  Change is one of the most constant features of American society.  For sociologists, social change occurs when many members of the society adopt new behaviors that have long-term and important consequences.  Discovery, invention, and diffusion are the major social processes through which social change occurs.  Important agents of social change are technology, changing demographics, the natural environment, and revolution and war.

7.  The functionalist perspective is based on the concept of equilibrium. A society is relatively stable; it reacts to changes by making small adjustments to keep itself in a state of functioning and balance.  The conflict perspective, however, views societies as inherently unstable systems that are constantly undergoing change as they struggle among groups for scarce resources.  Symbolic interactionism identifies decreasing shared values as a cause of social instability.

8.  Collective behavior describes how people behave when they are united by a single short-term goal.  Rumors, fads, legends, and fashions are examples of collective behaviors. Mass hysteria and panic are manifestations of collective anxiety and fear.  Sociologists identify four basic types of crowds—casual, conventional, expressive, and acting. The contagion, emergent norm, and convergence theories have been developed to explain crowd behavior.

9.  The social movement is the most highly structured, rational, and enduring form of collective behavior.  Most social movements are started to stimulate change.  The primary types of social movements are revolutionary, reformative, redemptive, and alternative.