Likely little change in the past 100 years. In the past the smarter people and their children were often killed, but that happens rarely in recent decades. The other things happening is we are keeping people with bad genes alive long enough to breed in recent decades, which deteriorates the gene pool.
Also the smarter people typically have fewer children, so long term = less intelligent. Neil.
Recently it has been postulated that for the past ten to seventy thousand years we have indeed become less intelligent.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.