[Unlike objects, people are] usually perceived as action centers and as such can do something to us. They can benefit or harm us intentionally, and we can benefit or harm them. Persons have abilities, wishes, and sentiments; they can act purposefully, and can perceive or watch us. They are systems having an awareness of their surroundings and their conduct refers to this environment, an environment that sometimes includes ourselves.

p. 21 ; as cited in: Albert A. Harrison (1976), Individuals and Groups: Understanding Social Behavior, p. 88 - The psychology of interpersonal relations, 1958