Optimism vs. Reality in Longevity Science: Analyzing Zoltan Istvan’s Senescence Inference

“Although [Zoltan] Istvan’s general pessimism is understandable, the Senescence Inference takes the pessimism too far for a number of reasons.”

Zoltan Istvan, a prominent figure in the transhumanist movement, recently wrote an article at Merion West explaining why many in the transhumanist community are “overly optimistic about the pace of life extension research.” Despite recent advancements in this field, Istvan’s down-to-earth assessment is most likely correct. There remains a vast chasm between lab studies that extend the lifespan of mice and the goal of extending the lifespan of humans—let alone the objective of reversing the aging process and unlocking immortality. Even as an overly-zealous proponent of the life-extension movement, I have to admit that the current pace of progress does not seem sufficient to warrant anything beyond cautious optimism. As Istvan writes, “biological humans are likely to be mortal for centuries more unless a dramatic increase in both resources and life extension scientists is marshaled.”

Istvan’s pessimism is grounded in a concept he developed called “the Senescence Inference,” which he describes as a kind of Moore’s Law for longevity. Just as Moore’s Law observes that the number of transistors in a chip doubles every year, the Senescence Inference, properly calibrated, would observe how the human lifespan expands as medical technology improves. To quote Istvan’s figures, someone born in 1901 had a life-expectancy of roughly 48 years, while people alive today can expect to live roughly to 72. This, Istvan writes, is a 1.5x lifespan expectancy gain from 1901 to today. Projecting this forward, someone born in 2021 can be expected to live to 110. This estimate is wildly out of step with life-extension proponents, who often make the claim that “the first person to live to be 1,000 years old is alive today,” or, as futurist Ray Kurzweil asserts, if one can live to 2030, he might be able to live forever.

Although Istvan’s general pessimism is understandable, the Senescence Inference takes the pessimism too far for a number of reasons. At a basic level, there is an obvious rebuttal to any argument that is pessimistic about technological advancement: In-the-moment predictions about technological advancements often wildly underestimate the prospect of unprecedented breakthroughs. For example, in 1903, a writer for The New York Times predicted that airplanes would not be functional for 10 million years. In reality, the Wright Brothers accomplished this only nine weeks later. And despite all odds and predictions to the contrary, humans set foot on the moon a mere 65 years after the Wright Brothers took flight. Similar overly-pessimistic predictions were made regarding atomic energy, the Internet, the adoption of the personal computer, and the Human Genome Project. So, when someone writes that scientists will not radically extend the human lifespan for centuries, there is quite a lot of precedent to shrug this view off as overly pessimistic.