Increased Longevity and Cultural Stagnation

One concern that people have about increasing healthy human longevity is that society would become stagnant and innovation would cease as a result of people living too long. However, stagnation probably won’t happen as a result of increased longevity.

Increasing human longevity vs the status quo

Steve Jobs once said that death is life’s single best invention because it gets rid of the old and makes room for the new. This view is the core of another fairly common objection to increasing human longevity: “cultural stagnation”.

Wouldn’t all those rejuvenated people, however physically young, be always old people “inside”, and drag everyone down with them into their anachronistic, surpassed ways of thinking, making it harder for fresh ideas to take hold, ultimately hindering social progress and our growth as a species? Maybe it’d be best not to take the risk, forget increased healthy longevity, and be content with old age as it is.

Try explaining to your grandfather that the reason he has to put up with heart disease is that we’re afraid that people his age may all become troublemakers if allowed access to medical technology that might increase their healthy longevity.

Facts, please

This concern implies that the death of older people is somehow essential to the thriving of society, and that is a very bold claim; as such, it requires extremely solid proof, because we can’t ask people to give up good health and life over someone else’s worst-case-scenario guesses.

Do we have compelling evidence that chronologically elderly people are so prone to stagnation that enough of them may actually have a negative effect on social development based on stereotypes? Are there any studies showing that people who live past a certain age inescapably become a drag on the advancement of the species? Assuming such a tendency in the elderly, is there any proof that it’s an unavoidable consequence of chronological age that can’t be interfered with?

Until those questions can be unequivocally answered affirmatively, the thought of forestalling this hypothetical catastrophe by opposing the development of life-saving medical biotechnology shouldn’t even cross our minds. Even then, denying medical treatments to a few people who might be a hindrance to society, or not developing the treatments at all, precluding their use to everyone, doesn’t seem a very ethical way to “make room for the new”.

In any case, we can’t predict the future, so we can’t rule out any doomsday scenario with 100% accuracy. The best we can do is figuring out how much, if at all, rejuvenation biotechnology and a possible resulting increase of healthy longevity might contribute to this problem and if there wouldn’t be a way around it that doesn’t involve letting people die.

Socio-cultural contributors of stagnation

If the problem is cultural stagnation, preventing people from living too long won’t solve it. There are no guarantees that generational turnover will necessarily lead to a majority of forward-thinking people. Leaving the matter up to chance, assuming that this will create the best outcomes, is a rather simplistic and short-sighted approach to the problem.

If old people today tend to be resistant to change and stick to their ways, it’s likely because the elderly of today come from an age when knowledge wasn’t readily accessible to everyone and the stages of life were still somewhat set in stone: birth, school, work, family, retirement, death.

In this framework, it’s clearly easier for young people to think out of the box since they’re starting essentially from a clean slate and are ready to absorb new information. A lot of the knowledge that young people have access to was generally not available at all when their elders were young. On top of that, as continuous learning isn’t part of this framework, new knowledge isn’t accessible to old people even later on.

However, old people aren’t automatically closed-minded. Learning opportunities play a big role in this sense. If you maintain a healthy skepticism even about your own convictions, never stop learning, and never let your gut take your brain’s place when considering a new idea, so why would you suddenly forget all of that and become the exact opposite of yourself in your old age?

Since we’re currently living in an age of ever-increasing free access to the whole of human knowledge, and continuous learning is actively promoted as a good thing, is it reasonable to expect that the young people of today, used to this new way of life, will lose their ability to learn simply because of chronological, not biological, age?

A society is only as culturally stagnant as its members, and as long as we offer access to knowledge, their chronological age is unlikely to matter much. A society where people could enjoy increased longevity would be unlikely to change that; if anything,  this may lead to a wiser society.

Biological contributors of stagnation

Neuroplasticity is the property of the brain to form new connections between neurons, and thus ultimately the brain’s ability to reshape itself, which enables us to learn new ideas and habits and thus change our minds. As such, it is definitely a necessary condition for avoiding stagnation: if your brain can’t rewire itself, you’re going to have one heck of a hard time learning new concepts or approaches.

Younger brains are generally more plastic than older ones, and they have more pronounced neurogenesis (the ability to grow new neurons), as explained for example in this TED Talk. The talk also explains how neurogenesis and its benefits can be fostered, giving us some control over our own learning ability. However, if neuroplasticity and neurogenesis are properties of young brains, sufficiently comprehensive rejuvenation therapies might be able to restore them.

It has been shown that brain plasticity can be induced. For example, antidepressants restore neuroplasticity back to more youthful levels in the cerebral cortices of adult rats [1, 2]. This effect has been noticed even in the visual cortex [3], and it could be induced even without the use of drugs [4].

A study on senescent cell clearance showed that elderly mice whose senescent cells were regularly purged exhibited some behavioral traits typical of younger mice, such as exploring a cage as opposed to sticking to its sides most of the time [5]. It is unclear if senolytic treatment has had an effect on the mice’s brain in terms of plasticity, but this result is a cause for optimism.

We cannot yet conclude that rejuvenation biotechnology will necessarily be able to restore youthful neuroplasticity to a brain of any age, but there is evidence that manipulating brain plasticity pharmacologically is possible to an extent; future interventions might help us exceed even that.

Literature

[1] Castrén, E., & Antila, H. (2017). Neuronal plasticity and neurotrophic factors in drug responses. Molecular Psychiatry.

[2] Karpova, N. N., Pickenhagen, A., Lindholm, J., Tiraboschi, E., Kulesskaya, N., Ágústsdóttir, A., … & Hen, R. (2011). Fear erasure in mice requires synergy between antidepressant drugs and extinction training. Science, 334(6063), 1731-1734.

[3] Vetencourt, J. F. M., Sale, A., Viegi, A., Baroncelli, L., De Pasquale, R., O’Leary, O. F., … & Maffei, L. (2008). The antidepressant fluoxetine restores plasticity in the adult visual cortex. Science, 320(5874), 385-388.

[4] Baroncelli, L., Sale, A., Viegi, A., Vetencourt, J. F. M., De Pasquale, R., Baldini, S., & Maffei, L. (2010). Experience-dependent reactivation of ocular dominance plasticity in the adult visual cortex. Experimental Neurology, 226(1), 100-109.

[5] Baker, D. J., Childs, B. G., Durik, M., Wijers, M. E., Sieben, C. J., Zhong, J., … & Khazaie, K. (2016). Naturally occurring p16Ink4a-positive cells shorten healthy lifespan. Nature, 530(7589), 184-189.