Some rules are universal, because they're thermodynamic. That's not to say that your species of intelligent individuals is impossible, but it is unlikely. When you really take the time to think through these scenarios, you often find that there is no justification to assume that exceptional intelligence would evolve.
If you're arguing against that suggestion, it seems you would have to be arguing that human intelligence exists at a level that is nestled directly up against some kind of hard thermodynamic limit, even though a non-trivial portion of our species already exists on the other side of that line. I don't see how that argument could plausibly be made.
But, like you say, we don't know we're screwed, so it's a lot of supposition.
If you don't think 20 IQ points make a significant difference, consider some questions: do you believe that the average IQ 100 person is more or less likely than the average IQ 120 person to be concerned about global climate change? What about IQ 100 vs. IQ 80? If IQ numbers have no tangible meaning to you, do you expect the average Walmart shopper to be more or less concerned about climate change than the average graduate student (in any field at all, your choice: agricultural engineering just as much as climatology or gender studies).
Case in point - Silicon Valley has probably an average IQ around 120-130. How many truly planet-saving innovations have been created there? I mean, you fail to eradicate powerty in SF, your backyard. Because why bother if creating ever new and exciting ways to share cat pictures is infinitely more personally rewarding in the short run and who gives a f about anything else?
So, my point is, higher IQ is not a solution in and of itself, since human nature - instinct to care about oneself first and foremost, will still be present. This instinct can be only tamed by education, culture and political and social structures that promote common good. The chances that a society will evolve these kinds of structures is a toss-up. It is a lot more likely that the outcome will be exactly the same as what we see now - much like adding a 1.2 multiplier to all stats for both mobs and pcs in a computer game - numbers are different, but it is still the same game.
The key is culture, and education, and conscious work towards better social, economic and political structures. But I am quite sure that we will all kill ourselves a long time before any of that will happen.
I agree with you that the mechanisms through which greater awareness and active concern for seemingly abstract problems will trickle into the global zeitgeist are things like education, culture, and social/political structures. But where do those come from, and what allows people to perceive their value and meaning? You can't teach people things that you don't understand, and they can't learn things that they can't understand. Better cultural and social structures are a result of better understanding; better understanding is more common with brains that are better able to perceive patterns and project consequences.
But we choose not to. There are loads of VERY smart people in the top positions of gigantic multinationals. They do not lack for IQ, or for information that without a shadow of doubt informs them about the long-term consequences of their actions. They choose, daily, to apply their IQ and information not to create solutions that would benefit humanity as a whole, but to maximize the short-term gains for themselves and (hopefully) their shareholders. The reasons for this behaviour are multitudinous and complex, but I would argue that lack of IQ is not a major contributing factor, quite the opposite.
And all that could still fall in the category of "fine, whatever", if in their greed they would not actively destroy the education system already in place, because people who lack basic knowledge and tools for critical thinking are that much easier to manipulate. Again, it is not the lack of IQ that is the issue, it is the knowledge and exercise it has been exposed to. I myself have an IQ well above average (Mensa member), but before I found out about heuristics, biases and critical thinking, and learned to apply them, I was an easy prey for "mediums", "spiritual guides" and other "new age" crap.
TL;DR people are easy to manipulate regardless of their IQ, if they haven't had an opportunity to learn to use it.
My 11 year old nephew sprained his ankle a few weeks ago playing basketball, badly enough that he started walking in an odd way to compensate for the discomfort. He kept playing sports, including soccer on a rough grass field, every day at school recess, despite us having talks several times about how he needs to stay off it and let it recover or else he risks causing lasting damage. He nods and says, "I know" when I tell him that, but he keeps doing it. I think we are collectively much the same: we 'know', but we don't really believe that the abstract, distant bad thing will ever really happen to us.That is not understanding. That is lip service.
My argument isn't that IQ makes every individual behave better - it is the statistical argument that if the population average went up 20 points (and that number is one I just threw out, but I do think it's close), then we might cross a tipping point where there would then be enough people who take abstract, distant bad things seriously enough to take meaningful action, to form a significantly politically effective bloc.
you mean the thing that allows any of those other things you listed matter at all?
and with all those abilities, it may make no difference, so there's no evidence that the difference in intelligence between yeast and humans is sufficient to save us. then why would 20 more points do it? and if yeast survive but people don't, what then? the point is in both the case of the yeast in the bottle and the human case our drive for survival kills us when we move into sudden abundance. greater average intelligence would just bring that abundance on faster.
since we can't seem to steer this ship, we're at the mercy of the currents. despite all our metaphors and plans and concern about global climate change we don't seem able to do anything. is there much of a difference in carbon footprint between your average walmart shopper and your average graduate student, concern notwithstanding?
20 points on average might push enough people from "unable to genuinely perceive long-term threats as threats" to "able to genuinely perceive long-term threats as threats", that it would move us past the political tipping point of collectively caring enough about doing something meaningful to both figure out what to do (devote money and resources to research) and to do it.
Individual carbon footprints are not meaningful - it doesn't matter how well an individual paddles their canoe when that canoe is in a swimming pool on a cruise liner. What matters is how the liner is piloted. If all people suddenly disappeared off the earth, except for those people who happened to be standing in Walmarts at the time, do you think that society would be better or worse at recognizing and handling abstract, long-term threats like global warming than the society composed only of graduate students would be?
And we ourselves are not that far from being able to deal reasonably with problems like this. If nothing else were different about us, except that average IQ were, say, 120 on the current scale, I think we'd be able to respond sensibly to non-immediate threats.