I was thinking and thought I referred to intellectual capacity so the ability to think things through, critical thinking not pure intelligence which is a measure of IQ. If you are creating lots of worlds with storylines that mimic real life so friendships, family relations, good and bad with your toy characters, then it develops empathy and emotional intelligence.
I had that connection with my DC from reading to them and by nurturing that imagination with helping them with ideas or putting on plays, puppet shows, dancing or whatever. I can't see how the above isn't crucial to child development, I know that it is as my Mum specialised in that area in her job and gave me lots of advice on how to go about this when my children were young. Equally, how can you dismiss kindness as irrelevant, it's arguably the most crucial element of a child's character if you want them to make good choices later in life. And affection, yes it goes without saying that that's essential for feeling confident and secure.
R.e 'dumbing down', there is an intellectual malady that we have descended into, lots of people finding it easier to just roll their eyes and not give a crap which means that actively engaging in civic responsibilities and understanding your position within a community, believing in something worthwhile, is now seen as sentimental but people still want to believe in something so that feverish desire has turned to hate as it is easier to do so than actively engaging in substantial issues which require a level of understanding and critical thinking skills that many lack or can't be bothered to pursue.
I disagree that those with greater intellectual capacity are easily indoctrinated, they aren't, purely because if you know enough stuff you can offer a credible condemnation of it. How can you do that if you don't even know what a democracy is or what government is or what ethics are for example! This is very different from having a high IQ. IMO, boys who are easily indoctrinated into thinking like this are angry but they don't even know what they are angry about, they can't articulate it and they certainly can't rationalise it.