This lecture explores the topic of proxemics, or the ways in which people use space in their day-to-day interactions with others. Four core processes of human spatial behavior are privacy, personal space, territoriality, and crowding. Examples of these processes and the ways they work together as part of a dynamic system to regulate individuals’ privacy needs are discussed. Cultural differences in people’s use of personal space and territoriality are illustrated. Also, distinctions between the physical conditions of spatial and social density as compared to the motivational state of crowding stress are noted. Finally, key differences between human and non-human territorial behavior also are described, as well as various types of human territories including primary, secondary, and public spaces.