The view is presented that the theory of altruism, mainly focusing on the origins and the stages of altruistic development in children, has understudied its varied manifestations in adults. That has resulted in some inconsistencies in a conceptual framework of prosocial behaviour research. The approach taken here attempts to clarify chosen elements of terminology and suggests a possible avenue for research. An analysis of the hypothetical levels in the development of altruism in adults is performed as an introduction to altruistic typology. Its implications, as they relate to prosocial behaviour theory and terminology are considered. Definitions of altruistic attitude and behaviour, pre-altruistic behaviour as well as helping and charitable behaviours are proposed. The nature of reinforcers of altruistic behaviour and their gradual extrinsic/intrinsic transformation is discussed. Altruism is regarded as a phenomenon resulting from a dynamic schema of psychological functions and simultaneously as an indicator expressive of the level and direction of their development.