One of the proposed benefits of life extension is that it will help us long term plan as we will be around in the future, so we will be more likely to care about the long term future of the world if we live longer.

So is this true? Are we rational in this respect or will the mind recoil from thinking in time scales longer than 40-60 years even when we are living hundreds of years, due to biases intrinsic to the mammalian brain.

I don't have time to research this question right now, so I thought I would experiment by throwing out this question to lesswrong and see how people treat it.

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The longer a plan takes, the more things will change before it comes to fruition. The world will be different tomorrow, and different again each day thereafter. Therefore, it is perfectly rational to make plans for the near future, but to wait for more information before making plans for the distant future. We can argue about the precise degree to which we should favor the short term vs. the long term in our plans, and there are some reasons to think that people have it mis-weighted, but simply telling people to "favor the long term more" won't do because it's possible to overshoot and neglect the present.

Modern rich humans live 80 or so years, but most of us have great difficulty planning (or following plans made for) more than a few years or maybe a decade out.

I don't think failure to think long-enough term is caused by our limited lifespans, so increased lifespan is probably not sufficient to improve it. In fact, the opposite is likely true: having longer views and considering multi-decade effects of today's action is likely to RESULT in longer lifespans.

Re: Is short term planning in humans due to a short life or due to bias?

Er, neither: short-term planning is rational in an unpredictable world.

I would argue all three contribute to the scarcity of long-term planning.

We don't know how to reliably plan for long term. We didn't have enough iteration of "long term" in any environment similar to our current environment to have any hope for long term planning to work. Try guestimating 2009 based on data from 1909 alone and tell me how it went. Or 2009 based on 1959.

Even the most basic things like human population, and GDP/capita cannot be estimated with anything remotely resembling reliability past a couple of decades.

You know, that list is surprisingly predictive. They got a lot of stuff wrong, but they managed to predict cell phones and even a primitive form of internet. They're about on par with Heinlein's Future History.

I would submit that it's less an issue of the biologically-imposed limit to our life spans than the biologically-imposed limit to our predictive abilities, to the amount of "moving part" data our brains can work with simultaneously. Considering that we only seem to achieve anything like accuracy when predicting events on a very, very small scale of both time and complexity, one might argue that we actually plan in too long a term.

Gary Becker mentioned in a class on human capital that in Africa, AIDS was reducing people's investments in education because it reduced their lifespan, and therefore the benefits of making that investment.


I think that we do plan long term. At least I do. It is just that long term plans have a lower quality than short term ones because I am much more likely to be wrong about what happens, and what influence my actions will have, in the long term.

I think that the failure of long-term planning in humans is not because we live any specific amount of time, but because we live for a finite amount of time. Only when days and years and decades all the way on up become unlimited (or practically so; we may always be limited by the heat death of the universe or something) and too cheap to meter would I expect to see explosions in long-term thinking.

Can you elaborate on why you believe that? I find it difficult to see how, if lifespans were still finite but measured in millennia instead of decades, it could not have major consequences for long-term planning (on the order of decades to centuries).

It's mostly an intuition backed up by observations of my own thinking around long-term plans; I don't think I would get any better at making them unless I were outright immortal. However, I'm not bad at making long-term plans to begin with. I suppose I could quite easily be an anomaly.

Does "expecting to live for 10,000 years or more" feel subjectively closer to the current status quo than to immortality for you? I'm guessing so, but it's certainly not the case for me.

They don't feel the same - it just doesn't inspire me to fantasize about doing anything much longer term than I already am when I imagine living to be 10,000. This may be because I haven't spent enough time fantasizing about living for lengthy, finite periods of time, or it may be because I already think long-term enough to cover that eventuality.