Final answer:
The belief in a genetic 'death gene' directing the body to age and die aligns with the concept of programmed factors of aging and represents a variant of the death gene theory of aging.
Step-by-step explanation:
The gerontologist's belief that our genetic material contains a death gene programmed to direct the body to deteriorate and die parallels the programmed factors category of aging causes. This view is essentially the death gene theory of aging, which is not listed widely but resonates with certain programmed aspects of cellular aging, such as apoptosis. This theory suggests that there are inherited genetic programs that dictate the process of aging and eventual death. It markedly differs from the cellular theory of aging which focuses on cellular damage and the evolutionary theory which looks at aging from the perspective of evolutionary biology.