So, hiding your brains becomes social survival!
I've always been of the firm opinion that more effort needs to be put into programs for the gifted. One major problem with this is public support. Football games draw interest and participation from the lay parents, chess games do not.
I think we've all seen a prejudice against intelligence. "That girl may be book smart, but she hasn't got a lick of common sense." "What a geek! I'm glad I've got a life!" Etc.
While there is a popular aversion to intelligence, I find it interesting that you talk about dumbing down being a social survival skill. That's not necessarily a bad thing. We all do this to one extent or another. When we talk about something we are more familiar with than the person to which we are speaking is, we do not use the same language we would if we were talking to a fellow enthusiast. This facilitates communication, but doesn't denigrate intelligence. Now, you might say this gives the less knowledgeable person a false sense of self esteem. I don't agree in most cases. Doctors speaking Latin to patients would serve little to no useful purpose. The people, in the end, would have gained nothing they didn't have or know before the conversation took place. However, dumbing down the language to the words a common man uses facilitates understanding and puts the doctor and patient, not on a level playing field, but on a mutually beneficial one.
I think the same principle exists when people with vastly different intelligence levels communicate. If done tactfully, the less intelligent person never realizes they were being spoken down to. That's a great "social survival skill," and not necessarily bad. Well, I've rambled incoherently for long enough. I need to get ready for work.