I think there is a connection here between holding your knife like a pencil and the growth of places like McDonalds.
You see, those kind of places didn't exist when I was growing up in the 50's and 60's. I'm not sure if "fast food" had even been invented over here in Britain. There was fish and chips and that was about all. So most eating was done sitting up at a table in the home, where good manners could be taught and monitored.
But increasingly places like McDonalds are being used for regular family meals, rather then eating properly at home. The last thing you need in McDonalds is a knife. I'm not sure if they have anyway.
Another change is the increasingly common habit of sitting on sofas, watching the telly, instead of using a dining room table. In the course of my work, I visit hundreds of homes every year and a lot of them don't even have a dining table and chairs, especially with poorer and uneducated families.
So is it any wonder that table manners are so bad these days ?
My poor Mum would revolve in her grave if she could see some of the slack behavior that passes for manners now.