Smile when you read this. We don't ordinarily try to turn academic theories upside down without a shred of academic evidence on our end. But we cannot quietly go along with what a linguist told a meeting of the Acoustical Society of America: that that smile we asked you for may be the remnant of a sign of submissiveness with origins in the animal kingdom. To be more detailed than the traffic will probably bear, the baring of teeth might seem hostile, but grinning from ear to ear changes the timbre of an accompanying cry to make it sound like one produced by a smaller beastie.
Well, we've come a long way, beastie. If the smile of friendship were a signal of submission it would be a shadow of a smile, indeed.
As a parent we know points out, those first baby smiles that come from nowhere can hardly be such signals. They make usm submit to them.m As for the accompanying gurgle. . . .