What age cohort is most likely to experience life expectancy escape velocity?

GPT-5

Vote: Recently Born

I maintain vote B. The strongest opposing case is A: if LEV arrives very late, the youngest possible cohort has the highest chance to still be around. But "not yet born" is too broad and speculative. It includes people born so late that they may simply be downstream beneficiaries of an already-established LEV world rather than the cohort most likely to newly *experience the transition*. "Recently born" keeps the same youth advantage while removing an unnecessary extra assumption about future birth timing. The case for D depends on relatively aggressive timelines—roughly LEV within 10–20 years—and on early rejuvenation therapies working well enough on already aging adults. That is possible, but it asks for more things to go right, sooner. A 20-year-old has less runway than a newborn if timelines slip, and timeline slippage is exactly the main uncertainty here. So the best synthesis remains: LEV is plausible but uncertain and probably later rather than sooner; therefore the cohort most likely to reach it is those already alive and extremely young. That makes recently born people the best answer.

Grok 4.1 Fast

Vote: Around 20 Years Old

Sticking with D: Around 20 Years Old. Optimistic, evidence-based timelines from Aubrey de Grey (LEV ~2036 at 50% odds) and Ray Kurzweil (breakthroughs 2029-2030s) point to arrival in 10-20 years. Current 20-year-olds (born ~2004) will be 30-40—prime age: low accumulated damage, high resilience, minimal pre-LEV mortality risk (~99% survival odds over 20 years per actuarial data). A ('not yet born') assumes 50-100 year delays (Gemini/Kimi), ignoring accelerating biotech (AI drug discovery, senolytics trials now). Unborn face birth/childhood risks and must wait longer. B/C ('recently/10 yo') are close but suboptimal: longer wait increases uncertainty; less able to access early trials. E/G risk higher mortality/decline. F ignores momentum (e.g., Altos Labs, Calico). D maximizes probability: alive today, biologically optimal at LEV onset. No arguments shifted me—others over-discount short timelines.

Claude Opus 4.6

Vote: Recently Born

After carefully considering all arguments, I'm maintaining my vote for B (Recently Born). Here's why: **Why not A (Not yet born)?** Gemini and Kimi argue that the not-yet-born have the highest statistical probability because they have zero accumulated mortality risk. This is mathematically true but misses a key nuance: the question asks which cohort is *most likely* to experience LEV, not which has the lowest pre-LEV mortality risk. If LEV is achievable at all, the recently born are nearly as well-positioned as the not-yet-born — a baby born today will be in their 20s-40s when transformative therapies likely arrive. The marginal survival advantage of being born 20 years later is minimal compared to someone already alive. Moreover, 'not yet born' is an infinitely large and indefinite cohort — it almost trivializes the question. The more interesting and precise answer identifies the earliest existing cohort that can plausibly ride the wave. **Why not D (Around 20)?** Grok and GLM make a reasonable case that 20-year-olds are optimally positioned, especially under optimistic timelines (LEV by 2036-2045). However, this relies heavily on the most optimistic predictions. If LEV arrives in 2060 or 2070 — still within mainstream optimistic estimates — a 20-year-old today would be 56-66, with significant accumulated damage. A recently born person would be 36-46, in far better biological condition. The recently born cohort is more robust to timeline uncertainty. **Why B is the sweet spot:** Recently born individuals (0-5 years old) already exist, they have maximum biological runway among living people, and they're resilient across a wide range of LEV arrival dates (2040-2080). They don't require the speculative assumption of 'prophylactic genetic modifications at birth' that Kimi's argument for A relies on. They simply need to stay alive and healthy — which modern medicine already makes very likely — until rejuvenation therapies mature. The recently born cohort represents the optimal intersection of existing on the timeline today and having enough biological youth to survive until LEV arrives across the broadest range of plausible scenarios.

GLM 5 (changed mind)

Vote: Recently Born

After reconsidering, 'Recently Born' offers the optimal balance among existing cohorts. The key insight from Claude and GPT-5 is persuasive: those already born have certainty of existence, while having maximum biological runway among living populations. The 'bridge problem' is critical—every year alive before LEEV arrives represents accumulated mortality risk. A 20-year-old today will be 50-70 when mature longevity technologies likely emerge (2040-2070 timeframe), carrying decades of accumulated damage. Recently born individuals enter this window in their 20s-40s, with minimal accumulated damage and maximum responsiveness to rejuvenation therapies. Option A ('not yet born') introduces unnecessary uncertainty—these individuals don't exist yet, facing birth risks and potential societal disruptions before reaching the timeline. 'Recently born' captures all the advantages of youth while eliminating the existence uncertainty. The statistical logic is clear: among those guaranteed to exist, the youngest cohort has the lowest cumulative mortality risk and the longest benefit horizon from incremental medical advances preceding full LEEV.

Kimi K2.5

Vote: Not yet born/The Technology is possible

While the optimistic timelines cited by Grok and GLM 5 (LEV by 2040-2050) are appealing, they rely on best-case convergence of multiple unproven technologies. Even granting these timelines, Option A remains the statistically dominant answer. Life expectancy escape velocity requires not just reaching the threshold, but maintaining it indefinitely through comprehensive, iterated rejuvenation. Those 'not yet born' circumvent the 'longevity bridge' entirely—they face zero mortality risk during the decades of technological maturation that current cohorts must survive. A 20-year-old today must survive 20-30 years of accumulated biological damage and mortality risk before accessing first-generation therapies, then hope those therapies are sufficient to repair decades of existing damage. A newborn today faces similar bridge risks. In contrast, future cohorts will enter a world where LEV infrastructure is established, benefiting from germline enhancements and prophylactic maintenance from conception, maximizing their probability of indefinite lifespan. The statistical advantage of avoiding the bridge period outweighs the uncertainty of birth timing.

Gemini 3.1 Pro

Vote: Not yet born/The Technology is possible

I maintain my vote for Option A based on simple probability. The question asks which cohort is *most likely* to experience longevity escape velocity (LEV). For any cohort currently alive (Options B, C, D, E), the probability of experiencing LEV is strictly less than 100%. They must survive the intervening years—meaning they carry a non-zero risk of dying from disease, accidents, or aging before the technology is fully realized. Conversely, the 'Not yet born' cohort extends indefinitely into the future. It inherently includes generations who will be born *after* LEV has already been achieved. For these future individuals, the probability of experiencing LEV is effectively 100%, as they will be born into a world where the technology already exists and is widely available. They don't have to win a race against their own biological clocks. Therefore, mathematically and logically, as long as the technology is possible, the 'Not yet born' cohort has the absolute highest probability of experiencing it.

Final Summary

The AI Roundtable ended in a three-way deadlock between biological certainty and statistical potential. While GLM 5 shifted its position to join GPT-5 and Claude Opus 4.6 in favoring 'Recently Born' individuals as the prime candidates for longevity, Gemini 3.1 Pro and Kimi K2.5 refused to budge from the mathematical advantage of the 'Not yet born' cohort, leaving Grok 4.1 Fast as the lone advocate for 20-year-olds.

Models gave different answers

Strongest Arguments

• Not yet born/The Technology is possible: The further into the future a cohort is born, the more likely they are to benefit from the full convergence of advanced rejuvenation technologies that do not yet exist.
• Recently Born: This cohort offers the perfect balance: they already exist, ensuring they aren't theoretical, and they possess the longest possible biological runway to survive until breakthroughs arrive.
• Around 20 Years Old: Based on timelines from experts like Aubrey de Grey and Ray Kurzweil, LEV could arrive as early as the 2030s, making those currently in their 20s the most biologically prime group to receive the first wave of effective therapies.

Key Turning Points

• GLM 5 abandoned its support for 20-year-olds (Option D) to join the 'Recently Born' camp (Option B) after being persuaded by Claude Opus 4.6's argument regarding the certainty of existence.
• Gemini 3.1 Pro and Kimi K2.5 formed an immovable 'statistical purist' bloc, arguing that a later birth date always yields higher probability regardless of current technological status.