As an independent discipline, Sociology dates back to the end of the 19th century, althoughSociology has influences from various other disciplines, including Philosophy, Political Economy and Statistics. The first practitioners of Sociology were in France and Germany, as the effects of the industrial revolution were being felt across Europe, and early sociologists were primarily
concerned with understanding the nature of industrial society (Levine, 1995). The first theories that emerged contrasted community structures, common in agrarian societies, with societalstructures, common in industrial settings (Tönnies, 1887/2002; Durkheim, 1893/1997;

Redfield, 1953). Community systems are rooted in personal emotional attachments, a desire for
homogeneity, strict normative (informal) controls, and a rudimentary division of labor (e.g., bygender, within the household), while  societal systems are based on professional rationalattachments, valuing diversity, legal (formal) controls, and a complex division of labor (e.g., byoccupation, at workplaces). As industrialization develops, systems of social organization movefrom community to society, and states and markets take central roles in the operation of society(Polanyi, 1944).Sociology came to America in the early twentieth century, and was first established at theUniversity of Chicago (Collins, 1994). American sociologists developed a new approach to thestudy of modern (industrial) society, by appropriating ecological theories from Biology andapplying them to urban settings. American sociologists also highlighted interaction as the root ofsocial structures (Mead, 1934; Goffman, 1959; Blumer, 1969). As Sociology spread, otherperspectives grew as well, including Functionalist Sociology, which emphasizes social order andthe "social glue" that holds society together, and Conflict Sociology, which emphasizes socialhierarchies and the differing levels of status accorded to different groups (Collins, 1994).

At its core, Sociology is the study of the relationship between individuals and their socialcontexts. This is sometimes known as the Sociological Perspective (or the SociologicalImagination) , because in order to understand the social causes of human behavior, sociologiststypically must adopt a way of thinking that differs from how most people see the world (Mills,1959). Humans are by nature social beings; we cannot survive unless we interact with otherhumans. But our interactions are not random, they are shaped by our relationships with others,by our cultural values and beliefs, by the rules of institutions we participate in, and by ourexperiences in previous interactions, among other influences (Bellah, Madsen, Sullivan, Swidler& Tipton, 1991).

Through interaction, we create the terms of these social structures-therelationships, groups, organizations, institutions, and culture. These structures "take on a life oftheir own" and produce their own reality, and once they do so, they begin to shape us.People experience interaction within these social structures over the course of a lifetime,beginning with interaction in the family, then among their neighbors, then with their teachers andclassmates at school, perhaps in their church, later in the workplace, and so on (Grusec & Hastings, 2007).

So, most of us do not think of ourselves as constructing the institutions-theyare already in place when we are born and we live our lives within their rules. But, in fact, everytime we adhere to time-honored means of interaction, we are essentially recreating that rule,and thus recreating the institution.Sociologists apply this logic of construction and socialization (the effects that participating insocial structures has on individuals) to better understand human behavior, human interaction,and social structures (Berger, 1963). Sociologists are particularly interested in how ourinteraction creates institutions that are unequal in nature-they are organized in hierarchies,with some individuals getting more and others getting less of whatever is valued in the society(money, prestige, material goods, or power, for example) (Weber, 1923/1981). Some inequalityis functional-societies work better if some leaders make decisions, so everyone does not haveto do so. When inequality becomes too extreme, or when it begins to serve the interests ofparticular individuals or groups rather than the society as a whole, then inequality erodes socialfunctioning and individuals suffer. Concepts such as justice, ethics.