> So the question that I don't know the answer to: would those couples have engaged each other in meaningful conversation (meaningful to them) had cellphones not existed? Or does the presence of cellphones reveal that a large number of people were never particularly interested in engaging meaningfully with others but would only feign interest when the alibi of the cellphone isn't available?

I would add a followup to that. Would this also mean that more people are together now that otherwise wouldn't, without that crutch?

Not sure I want anything said with that, but I couldn't help but draw the conclusion.