As it became clear that the environment can limit people, it also became clearer that people with severe disabilities had far more potential and capabilities than many imagined. In the 1970s and into the early 1980s people like Marc Gold clearly demonstrated that people with severe mental retardation could, indeed, learn to do complex tasks.

In that context, Gold defined mental retardation as "the level of power needed in the training process required for [the individual] to learn, and not by limitations in what he or she can learn". Gold further stated: "The height of a retarded person's level of functioning is determined by the availability of training technology and the amount of resources society is willing to allocate and not by significant limitations in biological potential."

The Gold definition placed the onus of responsibility on society to advocate for individuals with severe mental retardation and to ensure their quality of life, rather than on the individual. The commitment of resources and the interventions that society can and must provide empower people.

In other words, teaching strategies, adaptive technology, and the commitment or resources can remove the disadvantages in the environment.

The competency/deviancy hypothesis states that "the more competence an individual has, the more deviance will be tolerated in that person by others". The implication of the hypothesis is that even when sophisticated technology is not available or has not been developed to increase or change a person's behavior, the focus of that person's intervention should be on teaching him or her competencies.

Marc Gold's work on training in the 1970s helped develop the technology to empower people. It laid the groundwork for an ever increasing emphasis on competency and capacity from the 1980s on.