From my 50+ years of enquiry into existential risks and their possible mitigation strategies, I am now clear that the greatest source of existential level risk comes from the structure of our brains and wider cognitive architecture, and the evolutionary pressures to prefer simple certainty over complex uncertainty.
This delivers two different yet related sources of risk:
1 is a tendency to over simplify that which is truly complex;
2 is a tendency to be over confident where uncertainty is the appropriate response.
It is relatively easy to understand why both of these factors are present.
There are a couple of quite different major drivers for simplicity.
i) Time and energy are important factors in living systems, and evolution tends to select for the fastest and lowest energy system that is actually survivable (think of evolution essentially being lazy, and you will get a feel for how it works, even if the mathematics and strategy of it is deeply more complex than that).
ii) Then there is that fact that if you are to have a generalised network that is capable of learning, then it must start with relatively few constraints, and must then learn most of the distinctions it needs from experience. At least in the initial stages, most of that experience will be transferred implicitly via culture and language, and it must all start with simple distinctions. The simplest possible distinctions are binaries (one of two possible states), like True/False, Hot/Cold, Light/Dark, Wet/Dry, Sweet/Sour, Right/Wrong. We must all (as children) necessarily start from such simplicity, and such simplicity is always useful when urgent decisions are required.
Thus there is a real reward in many contexts for rapid response. If you are too slow to recognise rapidly approaching danger, or too slow to take effective action to avoid it, then your genes don’t make it to the next generation.
The huge issue with all of this, is that we now have vast sets of evidence that we humans are deeply complex, and contain many classes of fundamental uncertainty, and we live in a universe that is similarly deeply complex, and also fundamentally uncertain at many different levels and in many different ways.
Thus we have very strong tendencies to over simplify that which is truly complex, and then to be far too confident that we are correct in those simple conclusions, and to defend them as being “right” rather than to consider more complex and nuanced alternatives.
The evolved tendency for our subconscious brains to simplify under stress, makes this worse.
The more stressed we are, the more likely we are to experience people as “Friend” or “Foe” rather than as fellow deeply complex, cooperative and fallible individuals; and the more likely we are to consider ideas as “Right” or “Wrong” rather than as “some sort of useful approximation to whatever reality actually is that might have some sort of utility in some set of contexts”. Thus we end up in the almost paradoxical situation that those who are most certain that they are “Right” are probably least likely to actually have a useful approximation to any non-trivial situation that contains real complexity.
It is really hard to give up “being right” and to find a place of “uncertainty” where we are actually able to deeply consider ideas we have never considered before. The simple idea of “being right” is so powerful in all of us at some times, and in some of us at most times, that it prevents any real consideration of novelty. In extreme cases, it can prevent people even seeing novelty that is present in front of them, because it is subconsciously classified as something else, and we only ever get to experience what our subconscious systems decide to let through.
The more stressed we are, the harder it is to see anything new.
We have a lot of sources of stress in modern life.
Very few people experience sufficient abundance that they are able (much less willing) to examine the assumptions behind language and culture.
Simple ideas dominate.
One of those simple ideas dominating much of economics, biology and strategy, is the idea that evolution is all about competition. The reality is deeply more complex and almost the exact opposite for a species as complex as us. The actual reality, is that all new levels of complexity are founded upon and sustained by new levels of cooperation; and competition is only survivable if it is built on a fundamentally cooperative base. That has implications across all levels of economics, politics and strategy.
So our tendency to simplify, while useful, and even essential in some contexts, can in other contexts lead to our extinction, if we fail to recognise it for what it is.
What we need, are economic and political systems that meet the reasonable needs of all individuals for security and freedom; and that demands of all individuals levels of responsibility appropriate to the levels of freedom claimed – and such things can be deeply context sensitive.
Those systems need to recognise that any real freedom results in diversity, and any such diversity that is not an unreasonable threat to survival must be accepted and respected (all levels).
And all levels and classes of agents need to accept a fundamental responsibility for the maintenance of the biological diversity that make our sort of life both possible and interesting. Throwing waste away into the nearest environment is not a stable way of living, we actually need to recycle everything – one way or another.
So right now – our own necessary desire for simple answers, when applied inappropriately to situations that are in fact deeply complex and have no simple answers, does actually seem to be the greatest single source of existential risk for our species (and for many other species on this planet).