Surely this is a simple case of MANNERS, good or bad. It is thoroughly BAD MANNERS to ignore other people like this at a social occasion. But I also suspect there is something obsessive/addictive about nearly all the technology in use by folk today, they just can't seem to limit themselves or turn it off. I reckon it would be torture for them to be made to sit quietly in a room with no means of communicating, texting, hearing music or watching something on TV. It's similar to drug addiction in a way, they'd get withdrawal symptoms! Even in lifts,shops, my local bus, music is tinkling away, people are loudly declaring "I'm on the bus" etc. It's total madness, whatever have we become?