&gt; And then, on a national level, mean IQ has a much more pronounced impact (law of big numbers). Averaging down the intelligence of your population is an irreversible process. Once you mixed it down, the only way (for now) to bring it back up would be to be actively reproduce smart people for it. Even if you are not smart yourself, having high IQ people is needed to maintain and improve your surroundings. If I remember correctly, the US Army doesn&#x27;t accept people with an IQ lower than ~85 because it&#x27;s counterproductive to have them around.<p>I think the poster is suggesting making that decision for (presumably) his race.<p>Though implicit is the assumption that the natural way to group people is by ethnicity, but you could argue for grouping by country, social class, income, education, etc. For instance, I feel way more connection with techy&#x2F;nerdy people who grew up similarly than I do to, say, a gang member who spent years in jail but happens to be my ethnicity.