Primates live significantly longer than other mammals of the same size because their large brains act as a thermodynamic shield against aging.
High neural investment is usually studied as a path to intelligence, but it also serves as a physical strategy for extending life. By allocating a massive portion of the body's energy budget to the brain, primates reduce the overall entropy production within their physiological cycles. This thermodynamic efficiency allows a human to live much longer than a similarly sized deer or goat. The brain effectively slows down the biological clock by managing the body's energy use with extreme precision. Intelligence is a survival mechanism that physically keeps the body from falling apart rather than just a way to solve problems.
Neural Investment as an Entropy-Budget Strategy: A Thermodynamic Derivation of Primate Longevity from the Principle of Biological Time Equivalence
arXiv · 2604.27937
Primates exhibit a robust deviation from canonical allometric scaling: at fixed body mass, their lifespans exceed those of non-primate mammals by factors of two to three. A rhesus macaque (8 kg) lives 25-40 years, whereas a cat of similar mass rarely exceeds 18 years. This statistically significant clade-level excess cannot be explained by standard metabolic or ecological models. We provide a thermodynamic explanation within the Principle of Biological Time Equivalence (PBTE), where lifespan is