I agree you used chauvinistic to mean that, but you then followed it up by saying that you didn't have to justify why what they said is wrong. You do. It's also not the case that what they said was definitionally chauvinistic, although I'll let that slide because it was something similar enough.

Suppose it was the case that one nation was in every way better than all other countries. Shouldn't the citizens of that country be proud of that? Beyond pride, shouldn't they do everything they can to spread their glorious system to the world and bring prosperity to all? That doesn't necessarily mean wars and colonialism, that simply means all soft power efforts to implement systems that show themselves to work. I think the answer to this hypothetical is this nations citizens should feel pride and should spread their system.

The key point here is the United States isn't better than every country in the world, thus Americans shouldn't feel such extreme pride about their country. However, the United States is pretty good. I think some form of pride / patriotism are justified for Americans and even forms of soft power to implement effective policies are justified, but this answer is impossible to reach when you throw out all feel good thoughts about nations as chauvinistic.

Ah, what a great example of a thought terminating cliche, a statement that does what it says to save you from cognitive dissonance and nuance. You are clearly using chauvinistic as a pejorative, so you need to either justify how they're wrong or take it back and stop muddying the waters with your empty ideological language.

To be clear, I don't necessarily agree with op's statement. The US as a developed nation clearly has more opportunities and advantages than developing nations, but there are other developed nations that meet and sometimes beat the advantages the US brings. I'd argue the US is at least in top 3 of being the most successful nation in diversity and global influence, but other nations have better welfare programs, housing policy, and cultural aspects imo.

Another answer to your question is that it's fundamentally misguided due to your assumption that good and evil are absolute concepts and that there can't exist separate and consistent moral worldviews. Consider the historical crusaders joining a brotherhood of Christ to save their holy land from the infidels and secure safe pilgrimages for millions of their fellow Christians, and then consider a Muslim warrior defending his homeland and family in the name of Allah from crazed zealots of an imperfect prophet. Who is good there? If you asked them, they'd both say they're the good one and the other is the evil one. They'd both say the reason they KNOW they're the good one is ultimately due to insight into the moral fabric of the universe granted to them by God (the same god, funnily enough). Ultimately, it's impossible to say absolutely which one is right without appealing to something like divine revelation.

Another assumption I think you should reconsider is your implied stance that good people are necessarily absolutists in their principles. You say the good people wouldn't use nuclear bombs, but why? Nuclear bombs have ushered humanity into the greatest and longest period of peace in human history. You say the good people would never use torture, but why? I agree with other commenters that for practical purposes torture is nearly always useless and inhumane, but suppose a hypothetical hemophobic (and Evil!) nuclear terrorist that you'd just need to barely cut (light torture!) and then he'd tell you the secrets to his dastardly plan to bomb an orphanage. Are you sure that a good person would be obligated to stand by as the orphans explode instead of giving that guy a pinprick? Suppose the "good person" sticks to their principles and lets the orphans dies, what should they do to the terrorist? This guy's really evil, he spits on puppies and doesn't even feel bad about it. You also know with 100% certainty that he'll never reform, Doctor Strange told you so. If so, wouldn't it be more moral to just kill him? Why waste resources on his useless imprisonment when it could be spent on thousands of mosquito nets saving thousands of nonevil lives from malaria? Also, why is he evil? Suppose it's even 1% likely that evilness spreads through genes, if the good guy knew that and let him have kids wouldn't it be partially the good guy's fault if his nuclear terrorist baby bombs another orphanage? Perhaps you have satisfying answers to all these questions, but if you don't you just justified the torture, killing, and eugenics-ing of "evil" people.

Ultimately, the impression I want to leave is that ethics are hard and complicated and most certainly more nuanced than a good and evil divide. There exist counter arguments to some of the things I said in this comment, but I'm guessing exploration of those counter arguments would leave you with a more nuanced view of good and evil regardless.

To some extent you probably get more generally intelligent from practicing IQ tests in the same way you might get more generally intelligent from stretching your mind in any way. However, the increase in IQ score you achieve after practicing for the IQ test is (just guesstimating because there's obviously no studies on this) >90% due to learning the patterns of IQ tests and <10% due to increased general intelligence as a result of studying.

To answer as to why IQ is helpful, it's useful for making conclusions about how different factors influence intelligence. It's more difficult to prevent lead from poisoning people's brains when you can't conclusively say how much it's poisoning. Supposing all the people with low IQ scores due to lead poisoning practiced for the test to make themselves feel better with a higher score, their studying would muddy the stats and make for weaker arguments on the side of those wishing to ban excessive lead. IQ is also relevant to certain diagnoses, such as for the diagnosis of ADHD where a deficiency in working memory and processing speed but not elsewhere supports a diagnosis.

In terms of whether IQ / intelligence is 100% genetic, obviously not, I don't think I said anything that could even suggest that. I'm not an expert so I'd appeal to this link for specific answers. Just skimming it seems to suggest anywhere from 50% to 80% heritability of IQ, although heritability as a concept is kinda unintuitive and hard to apply to everyday things.

Very generous and wrong. Any psychiatrist would tell you to not practice, and a when not practiced it's a very useful metric. We couldn't make as strong hypotheses about the effect environmental lead had on earlier generations without IQ tests. We couldn't measure the very interesting trend upwards in IQ scores over time regardless of lead, which implies anything from a structural problem with the test to a real improvement in intelligence in the general population since the test's invention. We couldn't quantify the genetic or environmental influences on intelligence without IQ either.

It's like saying a psychiatric test for depression is bad because you can practice to know the answers a depressed person would give.

The way I see it, IQ is a proxy for this concept of generalized intelligence with the test also measuring more specific measures of intelligence like working memory and visual processing. It's certainly fine, even good, to practice the underlying mechanisms of intelligence, such as learning memorization techniques and practicing to improve your working memory and thus become more intelligent. It's not good for the validity of the test to practice the specific questions and sections they put on the test to artificially inflate your score while leaving your underlying intelligence unchanged. Veritasium did the latter, not the former in his video.

God that video annoyed me so much. You aren't supposed to practice for an IQ test. If you practice, whatever result you get is basically invalid as the test presumes you are approaching the problems for the first time. It wouldn't annoy me if it wasn't Veritasium, but he presents himself as a science educator and should know better.