In this example, I would guess that differences in the individual's desire and ability to think through the consequences of their actions is far more important than differences in there IQ.
This may be true, but "ability to think through the consequences of actions" is probably not independent of general intelligence. People with higher g are better at thinking through everything. This is what the research I linked to (and much that I didn't link to) shows.
This graph from one of the articles shows that people with higher IQ are less likely to be unemployed, have illegitimate children, live in poverty, or be incarcerated. These life outcomes seem potentially related to considering consequences and planning for the long-term. If intelligence is related to positive individual life outcomes, then it would be unsurprising if it is also related to positive group or world outcomes.
In the case of avoiding use of nuclear weapons, there is probably only a certain threshold of intelligence necessary. Yet from the historical example of the Cuban Missile Crisis, the thinking involved wasn't always trivial:
We had to send a U-2 over to gain reconnaissance information on whether the Soviet missiles were becoming operational. We believed that if the U-2 was shot down that—the Cubans didn't have capabilities to shoot it down, the Soviets did—we believed if it was shot down, it would be shot down by a Soviet surface-to-air-missile unit, and that it would represent a decision by the Soviets to escalate the conflict. And therefore, before we sent the U-2 out, we agreed that if it was shot down we wouldn't meet, we'd simply attack. It was shot down on Friday [...]. Fortunately, we changed our mind, we thought "Well, it might have been an accident, we won't attack." Later we learned that Khrushchev had reasoned just as we did: we send over the U-2, if it was shot down, he reasoned we would believe it was an intentional escalation. And therefore, he issued orders to Pliyev, the Soviet commander in Cuba, to instruct all of his batteries not to shoot down the U-2.
Both sides were constantly guessing the reasoning of the other.
In short, we do have reasons to suspect a relationship between intelligence and restraint with existentially risky technologies. People with higher intelligence don't merely have greater "book smarts," they have better cognitive performance in general and better life and career outcomes on an individual level, which may also extrapolate to a group/world level. Will more research be necessary to make us confident in this notion? Of course, but our current knowledge of intelligence should establish it as probable.
Furthermore, people with higher intelligence probably have a better ability to guess the moves of other people with existentially risky technologies and navigate Prisoners' Dilemmas of mutually assured destruction, as we see in the historical example of the Cuban Missile Crisis. We don't have rigorous scientific evidence for this point yet, though I don't think it's a stretch, and hopefully we will never have a large sample size of existential crises.
I'm not sure we have serious disagreements on this. Research on intelligence enhancement sounds like a good idea, for many reasons. I'm just choosing to emphasize that there are probably other much more effective approaches to reducing existential risks, and its by no means impossible that intelligence enhancement could increase existential risks.
Jamais Cascio writes in the atlantic:
Read the whole article here.
This relates to cognitive enhancement as existential risk mitigation, where Anders Sandberg wrote:
The main criticisms of this idea generated in the Less Wrong comments were:
These criticisms really boil down to the same thing: people love their cherished falsehoods! Of course, I cannot disagree with this statement. But it seems to me that smarter people have a lower tolerance for making utterly ridiculous claims in favour of their cherished falsehood, and will (to some extent) be protected from believing silly things that make them (individually) feel happier, but are highly unsupported by evidence. Case in point: religion. This study1 states that
Many people in the comments made the claim that making people more intelligent will, due to human self-deceiving tendencies, make people more deluded about the nature of the world. The data concerning religion detracts support from this hypothesis. There is also direct evidence to show that a whole list of human cognitive biases are more likely to be avoided by being more intelligent - though far from all (perhaps even far from most?) of them. This paper2 states:
Anders Sandberg also suggested the following piece of evidence3 in favour of the hypothesis that increased intelligence leads to more rational political decisions:
Thus the hypothesis that increasing peoples' intelligence will make them believe fewer falsehoods and will make them vote for more effective government has at least two pieces of empirical evidence on its side.
1. Average intelligence predicts atheism rates across 137 nations, Richard Lynn, John Harvey and Helmuth Nyborg, Intelligence Volume 37, Issue 1,
2. On the Relative Independence of Thinking Biases and Cognitive Ability, Keith E. Stanovich, Richard F. West, Journal of Personality and Social Psychology, 2008, Vol. 94, No. 4, 672–695
3. Relevance of education and intelligence for the political development of nations: Democracy, rule of law and political liberty, Heiner Rindermann, Intelligence, Volume 36, Issue 4