"Linguistic diversity can lead to lower trust levels." Yes, I believe that's true. I'd add that if you are going to push for trust and better communication via linguistic homogeneity, the lingua franca that works best is: - one that is easy to learn - one in which the speakers tolerate and can understand imperfect speaking I'm thinking of situations in history where there were insiders and outsiders based on one's complete mastery of a difficult to learn language (Attic Greece, for instance.) The increasing number of outsiders who could not speak Attic Greek undermined trust of the greater society of Classical Greece.

"There are folks who claim that such a lingua franca has already evolved within the community of people working for multinational corporations and doing business internationally, in the form of English with a restricted vocabulary and simplified syntax (“Globish”)." Yes, of course, it's English, at the moment. I don't think it's just confined to multinational corporations. Most university educated Europeans and Asians speak it as a second language. English is considered to be one of the easiest languages to learn to speak, at least to a functional level. I do think that there is a compromise to be made for less common languages. It's to have an easy to learn language like English (or Spanish) that everyone can learn and then to leverage the prosperity that comes from having a common language to promote more traditional languages. You see this in Canada with French and in Scotland with Scots Gaelic, for instance. There is a limit however, and it is not for free. To be successful, countries do have to decide which languages they are going to promote and finance. "It only means that a purely logical “deep” representation (as assumed in Desperanto) does not capture all significant correlations between word meanings." Yeah. I agree. For instance, it's often hard to translate irony.