Dumbing down

Darrell has taken up reading regularly since being married to a bookaholic - the only proviso is that I must keep him supplied with books - he doesn't want the hassle of having to chose them himself.
His current book is My Cousin Rachel by Daphne Du Maurier and at first he found it hard going. His chief objection to the book, as far as I can make out, was that the protagonist, who happens to be male, thinks too much. He declared that men don't think. Well, they think about work or sport or food or the other thing (!) but not about people and emotions etc. Far be it from me to argue with him.
However, he's now getting into it, and pointed out to me that there was no TV back then so maybe men DID think in those days.
Which made me think - with the advent of TV and other technologies, has there been a dumbing down of the general mind? As machines get smarter do we get dumber? If something needs an ernest application of the mind, it's easier to turn the TV on and decide to think about it when the PGA is finished. Or if we need a sum solved (how many Wii games can I buy with 100 dhs?), it's easier to plug it into our phone calculator.
Have we become more emotionally divorced? And stupider?
I'm sure someone (probably Roland) will be kind enough to point me in the direction of an entire book about this issue. I'd appreciate it, and will make the time to read it as soon as I get off my PC....