Positivity effect (aging)

Biological Parallel

Terminal investment explains age-related positivity shifts: when future lifespan shrinks, allocate to present quality over future vigilance. Old dogs react slower to negative vocalizations but maintain normal response speed to positive sounds—reducing threat-scanning when remaining years are limited. In a 10-year study of 232 female mule deer, older individuals increased relative energy to reproduction even as absolute reproductive capacity declined, prioritizing terminal offspring over long-term survival. Older rhesus macaque mothers spend more time in contact with infants despite having lower body mass and longer birth intervals. The pattern crosses taxa: as actuarial senescence advances, organisms shift from threat-oriented to reward-oriented processing. When you can't invest in tomorrow, optimize today.