Inclusive Fitness Theory
Evolutionary success can include effects on relatives as well as direct reproduction.
The Mechanism: Inclusive fitness accounts for an individual's direct reproductive success and the effects of its actions on relatives' reproduction, weighted by relatedness. It is an evolutionary bookkeeping framework, not a conscious goal pursued by organisms.
The Philosophical Pivot: A gene-centered account can illuminate why helping relatives may evolve without explaining the lived meaning of family affection. Mechanism and experience are different levels of description.
The Horizon: Inclusive fitness is one part of evolutionary theory and does not erase other explanations of cooperation, including mutualism, reciprocity, and group-level processes under debate.
Applying the concept to human decisions requires special care. Kinship does not determine moral obligation, and a biological model cannot tell people whom they ought to love or support.
A theory can widen the account of survival while leaving the meaning of belonging open.
A biological ledger can describe inheritance without measuring the meaning of care.
When I explain family care through shared genes, what emotional or social meanings does that explanation leave out?