Reproductive value is the expected number of offspring an individual will produce given their current age and condition. A young healthy woman has high reproductive value (many potential future offspring). An elderly woman has low reproductive value (few remaining reproductive years).1
Parental investment should be proportional to reproductive value: parents should invest more in high-value offspring (young, healthy, viable) and less in low-value offspring (old, sick, poor prospects).2
The prediction is counterintuitive: parents should invest less in children as they approach adulthood (reproductive value peaks), because the offspring can soon provision themselves. Parents should invest most heavily in young children whose survival is uncertain but whose reproductive value will peak if they survive.3
The theory predicts systematic shifts in parental investment across the child's lifecycle:4
Early Childhood: High investment intensity (feeding, protection, constant supervision) because survival is uncertain and reproductive value is unknown.
Adolescence: Peak reproductive value; parental investment begins transition toward independence because the offspring is approaching reproductive capacity.
Early Adulthood: Reduced parental investment as offspring become reproductively independent; parents redirect resources to younger offspring or to their own continued reproduction.
Parental Investment in Grandchildren: Renewed high investment (grandparental caregiving) reflecting the grandchild's high reproductive value and the grandparent's inability to produce new offspring.5