Given that intelligence, self-control, personality, and so on...
So I agree with you on the points of intelligence, etc. I would guess that most people do... although I guess I'm not certain of that. At the very least I would suspect that there is known causal evidence about these sorts of things.
By contrast, here's an article that explores how certain racial groups appear to be more violent, until you control for class and demographic, when they suddenly aren't. And yet a lot of conversation ignores the second half, which is actually the key to finding a solution.
As a man, I will note that one of the strongest correlates with violence is being a man. Given what we know about things like testosterone, there's probably a substantial degree to which this is genetically/biologically caused. I just find most people emphasize the genetic aspects more than they can reasonably be confident about. For example, regarding heredity of IQ:
"By age 3, a poor child would have heard 30 million fewer words in his home environment than a child from a professional family. And the disparity mattered: the greater the number of words children heard from their parents or caregivers before they were 3, the higher their IQ and the better they did in school.
30 million fewer appears to be about 12 million vs 42 million.
"And they argued that the disparities in word usage correlated so closely with academic success that kids born to families on welfare do worse than professional-class children entirely because their parents talk to them less." — The Power of Talking to Your Baby
Note also:
"They found that parents talk much more to girls than to boys"
So even within families, this can be an issue.
You said:
there are many people who want heredity to explain 0% of IQ
I've recognized a tendency in myself to attempt to go to 0%. Consciously I realize it can't possibly be that low, but I can't be confident it's more than 2%. Or rather, I think that genetics possibly plays a large role now, but that if we raised people better than we could essentially eliminate these issues without focusing on genes.
If, 300 years ago, you were to describe a society in which large portions of the population can do algebra, or several centuries earlier, you were to describe a society in which basically everyone can read, the people you spoke to would probably assume this was a society of high-intelligence people. Rather, it's just today's genetically-basically-identical people, who are learning more effectively, and more, period than people used to.
Sure, genes play a role. But I'm not sure what the value is in focusing on genes.
Well, to partially refute that: Bayesianly-speaking, if you meet someone who has X trait, you might want to update to whatever odds of them having Y correlated trait, sure. That would be generally valuable to have better predictive models. But the brain has trouble separating "I know that X and Y are likely to go together" and "I think that X is a root cause of Y". Especially the brains of people who don't train this stuff, meaning even if you can keep these thoughts separate in your head, they can be dangerous memes to spread, because self-fulfilling prophecies, etc.
http://pss.sagepub.com/content/14/6/623.short
http://dl.dropboxusercontent.com/u/67168735/heritability%20of%20iq.pdf
"Socioeconomic status modifies heritability of IQ in young children".
To make a long story short, this analysis of a large cohort of children assigned a 'socioeconomic status indicator' to each family they were following from 0 to 100 based on a large number of factors. They found that the heritability of IQ was a VERY strong positive function of socioenomic status. At the bottom, they think less than 5% of IQ variation is moderat...
LessWrong has been having fun lately with posts about sexism, racism, and academic openness. And here just like everywhere else, somebody inevitably claims taboo status for any number of entirely obvious truths, e.g. "top level mathematicians and physicists are almost invariably male," "black people have lower IQ scores than white people," and "black people are statistically more criminal than whites." In my experience, these are not actually taboo, and I think my experience is generalizable. I'll illustrate.
You're at a bar and you meet a fellow named Bill. Bill's a nice guy, but somehow the conversation strayed Hitler-game style to World War II. Bill thinks the war was avoidable. Bill thinks the Holocaust would not have happened were it not for the war, and that some of the Holocaust was a reaction to actual Jewish subterfuge and abuse. Bill thinks that the Holocaust was not an essential, early plan of the Nazis, because it only happened after the war began. Bill thinks that the number of casualties has been overestimated. Bill claims that Allied abuses, e.g. the bombing of Dresden, have been glossed over and ignored, while fantastic lies about Jews being systematically turned into soap have propagated. Bill thinks that the Holocaust has become a sort of national religion, abused by self-interested Jews and defenders of Zionist foreign policy, and that the freedom of those who doubt it is under serious attack. Bill starts listing other things he's not allowed to say. Bill doesn't think that the end of slavery was all that good for "the blacks," and that the negatives of busing and forced integration have often outweighed the positives. Bill has personally been the victim of black-on-white crimes and racism. Bill is a hereditarian. Bill doesn't think that dropping an n-bomb should ruin a public career.
Here's the problem: everything Bill has said is either true, a matter of serious debate, or otherwise a matter of high likelihood and reasonableness. Yet you feel nervous. Perhaps you're upset. That's the power of taboo, right? Society is punishing truth-telling! First they came for the realists... Rationalists, to arms!
Or.
We can recognize that statements like these correlate with certain false beliefs and nasty sentiments of the sort that actually are taboo. It's just like when somebody says, "well science doesn't know everything." To this, I think, "duh, and you're probably a creationist or medical quack or something similarly credible." Or when somebody says, "the government lies to us." To this, I think, "obviously, and you're likely a Truther or something." Bill is probably an anti-Semite, but Bill doesn't just say, "I'm an anti-Semite," because that really is taboo. He might even believe that he shouldn't be considered something awful like an anti-Semite. Bill probably doesn't think Bill so unpleasant.
That's the paradox: "taboo" statements like black crime statistics are to some extent "taboo" for sound, rationalist reasons. But "taboo" is not taboo: it's about context. People who think that such statements are taboo are probably bad at communicating, and people often think they're racists and misogynists because they probably are on good rationalist grounds. If you want to talk about statistical representatives on the topic of race, be ready to understand that those who are listening will have background knowledge about the other views you might hold.
All this is the leadup to my question: what highly probable or effectively certain truths are genuinely taboo? I'm trying to avoid answers like "there are fewer women in mathematics" or "the size of my penis," since these are context sensitive, but not really taboo within a reasonable range of circumstances. I'm also not particularly interested in value commitments or ideologies. Yes, employers will punish labor organizers and radical political views can get you filtered. But these aren't clear matters of fact. I also don't mean sensitive topics like abortion or religion, nor do I mean "taboo within a political party."
Is there really anything true that we simply cannot say? I have the US in mind especially, but I'm interested in other countries as well. I'm sure there are things that deserve the label, but I've found that the most frequently given examples don't hold water. I think hereditarianism is a close contender, but it's not an "obvious truth." Rather, my understanding is that it is a serious position. It's also only contextually taboo. If it were a definitive finding, it could perhaps become taboo, though I think it more likely that it would be somewhat reluctantly accepted.
Any suggestions? If we find some really serious examples, we might figure out a way to talk about them.