PIP: Genetic counselors are generally trained in genetics only and often have no basis for determining when a counselee has made an informed decision and the counselor's function is complete. A theory of genetic counseling (GC) is offered which interrelates genetic information, psychological responses, learning theory, and decision making, reflecting a shift from a eugenic orientation to an orientation concerned with the physical and mental well-being of counselees. GC is 1st defined as enabling the counselee to comprehend the medical facts of genetic disorders, heredity, risks, and alternatives, as well as to make a healthy adjustment to a family member's disorder and risk of recurrence. The process of learning is broken down into a hierarchical relationship between acquisition, understanding, and personalization of facts, and applied to the GC situation; e.g. "the options are as follows;" "they can be exercised by couples in certain ways;" and "we have the following choices to make." Personalization of knowledge means integration into one's own value system where it will affect decisions made, a process affected by factors such as stress. Often, the information provided by GC is not the only information the counselee possesses, and it will be integrated with other conceptions. Normative social influences (e.g. a family's attitude towards abortion) affect the behavioral intention. And finally, the behavioral intention is not always equivalent to the actual behavior. These process are all related to the way in which a family deals with the stress caused by a genetic disorder. GC outcomes are easier to measure than those of psychological counseling. Extending the model to clinical application implies 1) assessment; 2) setting objectives; 3) counseling; and 4) evaluation.