The Convergence of Intelligence and Longevity

Humans are the most intelligent mammals and the longest-lived. Intelligence and longevity are characteristics of our species, and they probably evolved together. They are also individual traits; individual differences in intelligence, health, and longevity are directly correlated. People who are cognitively well-endowed are more likely to possess a number of favorable physical attributes, including disease resistance and longevity. The convergence of intelligence and longevity during evolution was inevitable. Something as extraordinary as the human brain can only have evolved in an organism whose physiological systems are highly reliable, efficient, and coherent. The human brain takes about 30 years to achieve maturity, although a case may be made for 50 or 60 years. A brain that requires such a long period of development needs a strong supporting cast in the soma. The resilience and longevity of the brain are reflected by the same qualities in the soma, and several ideas have been put forth to explain the association. We propose that the genetic elements that engineered our efficient and durable brain have exercised similar effects on our somatic systems. Almost all of the genes that generate and maintain the human brain are also active in the periphery, endowing our tissues with the same efficiency and durability. The speed, flexibility, and efficiency of neural networks are homologous with similar attributes that govern the behavior of gene networks for intelligence and longevity.