Although there are several plausible theories regarding possible underlying sociological and/or psychological mechanisms, there is as yet no proven explanation for this enigmatic effect:
“…our data do not reveal the specific process(es) that may account for the relation between smiling in early life and divorce.”
The study was published in the June 2009 issue of the journal Motivation and Emotion. A full copy may be found here:
Supporting material. One of the most famous smiles in recent Western history, belonging to Lisa di Antonio Maria (Antonmaria) Gherardini, who was not, as far as is known, divorced.
