Stanford University has published research that analyzes the development of human beings through blood samples from 4,263 volunteers. This detailed study explores changes in the body and the advancement of biological aging, which is influenced by the behavior of proteins in the blood. The researchers have established a framework for understanding human aging, which is divided into three distinct phases based on molecular changes encountered throughout an individual's life.

The first phase is identified as adulthood, spanning from 34 to 60 years old. In this phase, individuals generally maintain their physical capabilities as the body reaches its peak functioning. The second stage, referred to as maturity, occurs between the ages of 60 and 78, during which individuals begin to experience the initial signs of aging, although still active and capable.

Finally, the study concludes that biological aging is formally recognized to begin at 78 years old. This pivotal finding suggests that societal perceptions of aging may need to shift, respecting the scientific delineation of aging stages based on biological evidence rather than just chronological age. The implications of this research extend to health care, sociological perspectives on aging, and public policy related to elderly care and support.