It means that any political argument, any social policy, any philosophy, predicated on the cognitive abilities of groups being equal, needs to be re-evaluated. A lot of things have it as a hidden assumption. Here are a few examples:
Immigration. In order to make a proper analysis of what X number of migrants per year will do to the country, it's not enough to assume that each potential migrant has the same cognitive capacity relative to both other migrants and to the natives. If migrants from ethnic group A have a higher IQ than ethnic group B, is it a good idea to let a lot of Bs into the country?
School performance. Though it has closed a little over the decades, the gap between Black and White achievement in schools remains persistent and large. All manner of interventions have been tried to try to close the gap. If it is due to a real genetic difference between the two groups, much of this may have been pointless. Given what we also know about the drawbacks of mixed-ability classrooms, segregation comes back on the table as a plausible candidate.
Fertility. In the US, the White total fertility rate is below replacement (1.84), while Blacks are just above (2.11). Hispanics are even higher, at 2.99. What implications does this have for the intellectual capital of the USA in the coming decades?
International competition. China does not have the same taboos on group differences in cognitive ability that the Western world does. They are also quite happy and capable to do immense social engineering programs. Putting the two together ...
If migrants from ethnic group A have a higher IQ than ethnic group B, is it a good idea to let a lot of Bs into the country?
It is much more effective to give individuals IQ tests rather than try to divine the results based on weakly correlated features such as ethnic group.
Now, it is said we all here pride ourselves on our intelligence, rationality, and moral sense. It is also said, however, that we are a fiercely independent bunch, and that we can let this pride of ours get the better of us. There have also been comments that the live communities that appear at meetups provide much more positive interactions than what goes on on this site's discussions; this might merit further investigation.
My point is; we've done a lot of research on how to do proper ethical and metaethical calculations, and on how to achieve self-empowerment and deal with our own akrasia, which is awesome. We've also done some work on matters of gender equality, which is very positive as well. But I haven't seen us do anything about the basic details of human interaction, what one would call "politeness" and "basic human decency". And I think it might be useful if we started tackling these, for our own sakes, that of those who surround us, and that of easing our mission along, which is, as I understand it so far, to save the world (from existential risk (at the hands of (unfriendly and self-modifying) artificial intelligence))).
What inspired me to propose this post was a video I just saw from Hank Green of the famed and fabled vlogbrothers. I hold these two individuals in very high esteem, and I would expect many here to share my feelings about them, on account of their values and sensibilities largely overlapping with ours; namely the sense that intelligence, knowledge and curiosity are awesome, and that intellectuals ought to use their power to help improve themselves and the world around them.
Here it is; I hope you enjoy it