In the present article, I am examining, expanding, and re-evaluating a Lewinian kind of cultural psychology for cultural-psychological informed practitioners. Originating from Lewinian field theory that behavior is a function of a person and environment, B(f) = P,E, I am introducing a specific equation wanting to illustrate Lewin’s theory about cultural psychology. A person is driven by specific needs and goals that develop while him relating to his very own environment. Yet, how these needs and goals are pursued and satisfied (I call that trajectories) depends to a large degree upon his social environment showing him not only which goals are worth pursuing but also which ways to choose in order to attain them. Culture is thus a function of a person’s needs and goals that develop while him relating to his environment and henceforth to the life space of the social other—such as to one’s family—but also implying a specific unique social situatedness within the environment that can alter the culturally accepted way how to reach a specific goal. It is within such a perspective that I deduce a normative appeal character of cultural psychology grounded within Lewinian field theory that can be made fertile for people identifying as cultural-psychological practitioners. In the second part of the article, I am comparing a Lewinian (normative) understanding of cultural psychology with other prominent theories such as the one of Boesch, Bruner, and Valsiner reaching the conclusion that such a Lewinian understanding of cultural psychology is in accordance with their theories.