FWIW, after reading the 40 or so comments posted so far, here are some of my thoughts, observations and things I've learned after submitting the original post (in no particular order):
1. Either there are very few people on HN who can relate to this "problem" (when I put something in quotes, it sometimes means I am doing so for the sake of brevity ie. I understand the implications and various connotations of a term but explaining that I do would take up to much time/space. Like now.), or they felt more compelled to comment on aspects of my post than post their own experiences. Both of these explanations echo what I've observed in the real world and on other sites
2. Intelligence is a very touch subject for many people. Many people chose to comment on my choice of using the phrase "dumbing down". I'm still trying to find a good choice of words that doesn't need to fill entire paragraph, and that can adequately express what I mean. I think the audience here plays a big role is choosing the correct phrasing.
3. I should spend more time thinking about the examples I cite. A few people based parts of their comments around the fact that I mentioned "strip club" (apparently sex still sells). I don't enjoy strip clubs at all. I mentioned it because a) it's true, b) I thought it would provide a good contrast.
But more importantly, instead of spending time agonizing over examples (I spent quite a bit of time considering whether or not I should use the "10% of our brain" bit), perhaps I should try to express more clearly that I'm talking about patterns of behaviour, rather than individual occurrences.
4. I'm under no illusions - it's very, very difficult if not impossible to generalize human behaviour. People are different and they can interpret things in very different ways. Culture also plays a very big role. That's why I don't really expect to find the answer here or anywhere else. (Maybe there isn't an answer? Maybe this is a non-problem?) I just tend to look for patterns in responses and try to improve/change my own attitude, mindset, communication and relationships with people (if I do find great advice, it's a bonus). Most of the replies I've read have misinterpreted something I've said. That could be partly my fault and/or partly the reader's.
5. One can't really quantify aspects of social relationships objectively, so you resort to using qualifiers like "tend to", "many" (instead of "any"), and "probably" etc, rather than talking about "10% of the time", or "60% of my discussions". But considering that most people seemed to ignore these qualifiers, is this really the best way to express these ideas?
6. Believe it or not, I get along with people very well. I know about adapting to different situations and can do it with great ease, and I do recognize what I'm talking about as my own shortcoming rather than blaming others.
There are many other things but I think these are the most significant for now.