WHO defines healthy ageing around developing and maintaining the functional ability that enables well-being in older age, shaped by intrinsic capacity, environment, and their interaction.

This page isolates one claim from the wider argument of The Human OS Manual.

The classification describes the evidence supporting this claim, not the Human OS framework as a whole.

The 2015 WHO World Report on Ageing and Health and the associated Lancet policy framework center healthy ageing on functional ability rather than survival alone. Functional ability reflects intrinsic capacity, relevant environmental characteristics, and their interaction.

This is a public-health framework and definition, not evidence that one specific lifestyle preserves every domain of function or that functional ability can be reduced to one clinical measure.

The Human OS uses this framework as a compatible external definition for the book’s emphasis on access and capability across added years.

Sources are listed according to the role they play in this claim. One source may provide direct support, another may explain a mechanism, establish a limitation, or prevent an interpretation from becoming broader than the evidence allows.

The printed book preserves the claim inside the argument that gives it meaning. These references connect the current digital record to the first-edition evidence trail.

This claim connects to the following parts of the Human OS architecture. The module labels locate the claim inside the framework; they do not imply that the research source validates the architecture itself.