I've actually been aware of this debate since 2010. And quite frankly the hereditarians are probably right. Not least of which because the Egalitarians were always the more manipulative side in any debate: trying to shift the debate into minutiae or using audience condemnation to their advantage.
 
The Hereditarians made me want to study what I am currently studying. As such I would like to guide readers of this through the basics of this. Help them understand the debate and some of the immediate political implications of this (that will wait until the end). I confess, I will tip my hand with the political talk but I will try to keep it focused on a few central points that I do not think are controvertible. I may throw in some errant details that are debatable but that's not the focus of the issue. Remember that.
 
And for full disclosure, the reason I care is because half of my family is from South Africa. That nation has seen firsthand what denying this looks like.
 
But of course that brings me to my next point: none of this justifies brutally murdering the lesser beings or anything like that. Moral value is something entirely different.
 
But do keep in mind that also applies to the people who just wanted to keep their homes and neighborhoods a nice place filled with people like them.
 
1. This is almost certainly true. The Egalitarians in the debate have run rather short on evidence as genetic technology improves, and for a while they simply resorted to assuming their position was the default and critiquing hereditarians from that position. The former being the issue. It reflects that their position was not dependent on evidence but rather the hegemony of their ideas and status. Hereditarianism was the low status underdog
 
2. The reason why it is almost certainly true is based on the truism that nature doesn't have a goal or a moral compass. To assume nature left everyone the same in the brain, when the brains of different races have morphological differences on average no less, is to impart contemporary human morality onto nature. Nature is cruel and capricious really. So whenever we find a gene with influence in the brain and it isnt evenly distributed, it is unlikely nature balanced it all out in the end by giving every other population compensatory genes. In fact is is impossible.
 
Even worse, the effects of civilization on our genetic makeup is not 0, in fact it is a lot. And different people have lived in different societies with different pressures for difference periods of time. Enough time for specific adaptations to take place https://en.wikipedia.org/wiki/The_10,000_Year_Explosion
 
And most damning of all, researchers Wu and Zheng found that different human population groups differed more in the brain than anywhere else in the body.
 
3. Iq is not everything. Population groups differ in many respects. Just because one group has a higher IQ, for instance, does not necessarily mean they will make a nicer society or make better neighbors. Case in point: Western Nations routinely outscore East Asian nations on most metrics (that Westerners care about anyway). I could elaborate further but I will instead just pre-empt the charge that Western Nations getting a headstart or benefiting from Colonialism explains this. It does not because the biggest colonial powers or earliest risers in Europe are rarely the best places to live in Europe, nor the most materially well off.
 
4. Now we get political. This is where things get messy and biased so I will stay close to the shore. The European Far Right is not only totally right about demographic concerns, they are honestly not strict and exacting enough. Every pro-open borders claim is a bold faced lie. Even intelligent groups don't exactly assimilate, they're merely law abiding so nobody cares that much. But even so, there is an argument that they still compete as groups against the majority. Chinese ethnic politicking in Australia and Canada especially is one such example. Different people are different and have different interests. That's why diversity is inherently a challenge, not because of underperforming groups. That's only sometimes a problem. Now this doesnt mean high IQ immigration cant be a benefit, but it is not a panacea with no drawbacks
 
To get grandiose for a moment: group cohesion and dynamics matter a lot. Even intelligent newcomers can undermine this in sufficient numbers as the interests of both groups collides. In fact there is a paper submitted to the Pentagon in 2013 outright arguing that China's biggest advantage over the US is its homogeneous unified society. This gives it a resiliency the US lacks. And the paper minces few words to say that this is maintained by a racist belief in Chinese exceptionalism. I choose my words carefully here because the paper points out that America used to have this as well. In fact, China's Pride is remarkably similar to American exceptionalism http://archive.is/mENR7, it sees itself as unique among nations and with a great destiny. For America an overriding belief in its own exceptionalism rested on a foundation of Anglo Protestant Values. I would point out that this was strongest during the Great Depression and saw the nation through that, World War II, and culminated in the Moon Landing. Not a time when universal tolerance was seen as the greatest value.
 
5. A lot of the things people (Europeans) criticize America for are due to the diversity. Either directly by dragging down the average or indirectly by digesting political resources. Not the evil right wing policies America enacts. To go further, a lot of the things left wingers like to use to attack Republican policies (like that Republican States suck) is also due to this. The fact that Red States are poorer and less educated has a lot more to do with many of them being in the South. Which has a large population subset that drags it down, tend to be composed of whites who are from more clannish European groups, and lost their talented tenth because of these factors (and the Civil War). Nobody talks shit about Utah aside from attacking Mormonism.
 
Now obviously I am not saying Right Wingers are always right. But they didn't bet all their political capital on diversity, some societal standards are needed to maintain a moral order, and free markets are good (at least domestically)
 
6. Rhodesia and South Africa. Those countries got fucked over and are worse places to live now. And it was all because of other White Nations sanctioning them until they folded.
 
Rhodesia once fed all of Africa. Now it cant feed itself.
 
South Africa once had a burgeoning Nuclear Program. Now it has blackouts