This integrative review presents the Agentic-Communal Model of Advantage and Disadvantage to offer insight into the psychology of inequality. This model examines the relation between individuals' position of advantage or disadvantage in a social hierarchy and their propensity toward agency and communion. We begin by identifying and reviewing four inequalities — Resources, Opportunities, Appraisals, and Deference, or the ROAD of inequality — that are fundamental to social advantage and disadvantage. We explain how these inequalities can instill a sense of advantage and disadvantage in individuals. Next, we discuss two core drivers of human behavior: agency and communion. We integrate these literatures to introduce the model's central propositions: a sense of advantage orients individuals toward agency and a sense of disadvantage orients individuals toward communion. We review evidence for this model across four distinct social hierarchies: power, social class, gender, and race. A number of findings suggest that higher-power individuals, higher-class individuals, men, and Whites express greater agency, whereas lower-power individuals, lower-class individuals, women, and minorities express greater communion. We also consider results in the literature that appear inconsistent with our propositions (i.e., when the advantaged are communal and the disadvantaged are agentic) and offer theoretical integrations to resolve these apparent contradictions. In particular, we highlight how the orthogonal nature of agency and communion can produce behavior that results from the combination of high agency and communion. To help motivate a future research agenda, we note the importance of both hierarchy salience and cultural considerations in determining individuals' orientations toward agency and communion. Finally, we consider the implications of this model for the study of social hierarchy and inequality, as well as the consequences of rising inequality levels.