When did political leaders first start showing their teeth in official photographs?

This is a question that occurred to me as I was looking at Wikipedia's list of Vice Presidents of the United States to try to answer a question I had about former Vice Presidents who run for the presidency.

Most of these VPs are not smiling at all, and it seems that only a hint of a smile seemed consistent with the exercise of political power. They look grumpy to us today, but presumably the idea was to look completely serious. We expect smiles now. The emergence of teeth comes in 1953 with Richard Nixon, a person whose smile made many people uneasy and suspicious, oddly enough.

Here's the list of U.S. Presidents, with their official pictures. The first one to smile showing teeth is JFK. Beginning with Gerald Ford in 1974, all the Presidents are smiling showing teeth, except one — Barack Obama.

The baring of teeth is a serious matter. How and when did it become part of a nice, warm smile? "How Did the 'Smile' Become a Friendly Gesture in Humans?" (Scientific American):

Anthony Stocks, chairman and professor of anthropology at Idaho State University, responds: "The evolution of smiles is opaque and, as with many evolutionary accounts of social behavior, fraught with just-soism. Among human babies, however, the 'tooth-baring' smile is associated less with friendship than with fright--which, one might argue, is related to the tooth-baring threats of baboons. On the other hand, a non-toothy, not-so-broad-but-open-lipped smile is associated with pleasure in human infants. Somehow we seem to have taken the fright-threat sort of smile and extended it to strangers as a presumably friendly smile. Maybe it is not as innocent as it seems. All cultures recognize a variety of mouth gestures as indexes of inner emotional states. As in our own culture, however, smiles come in many varieties, not all of them interpreted as friendly."

Here's "When did humans start to smile?" by Professor Antony Manstead (British Academy):

The fact that humans can control most of their facial expressions, including smiling, adds considerable complexity to the relationship between smiling and emotion.... Portraits of men and women typically depict them with a serious, unsmiling expression. The ‘smile’ of Leonardo’s Mona Lisa is an exception, although the fame of the painting arises partly from the ambiguity of the expression. In any case, her smile is not one that shows her teeth. Colin Jones FBA’s study of smiling in French 18th-century paintings charts how the depiction of a smile showing teeth emerged between 1700 and the 1780s. He argues that the absence of such smiles in earlier portraiture stemmed partly from the tooth rot caused by sugar and poor diet, and partly from the aristocratic perception that smiling and laughter were manifestations of a lack of self-control and an absence of good manners....

In a recent study of nearly 38,000 yearbook photographs taken between 1905 and 2013, Shiry Ginosar and colleagues showed that the breadth of smiles increased steadily until the 1950s, when it became the norm to smile for such photographs. As with the changes in portrait painting, these changes can be explained in terms of material factors and social conventions. The material explanation relates to the lengthy exposure times that were needed in early photography, necessitating the maintenance of a pose for seconds....

The social conventional explanation is one proposed by the historian Christina Kotchemidova, who has argued that Kodak, the major player in the rapidly expanding photographic market, sought through their advertising to associate photography with happy occasions like holidays and travel, making the smile the obvious expression to be shown in a snapshot.

The relatively recent phenomenon of smiling in portraits can be attributed at least in part to cultural norms, but these vary from country to country. Studies have shown that the same person is likely to be judged by others as less intelligent when smiling than when not smiling in certain cultures.... Jeffrey Girard and Daniel McDuff analysed the facial responses of more than 850,000 people from 31 countries as they viewed television advertisements. They found that people smiled more when they were from countries that are high in individualism and low in population density. However, the strongest predictor of smiling was ‘historical heterogeneity’: an index of a country’s record of immigration diversity over time.... In countries with a long tradition of diverse immigration (such as Brazil and the United States), people shared neither a language nor social norms but nevertheless had to get along with each other. The absence of shared norms and language made it more difficult to anticipate how others would act or react, but this lack of predictability could be reduced by making one’s feelings and intentions explicit through one’s nonverbal displays....

That's the cue here at Meadhouse to start singing "Wooden Ships"...

Anyway... in the current election season, you've got a big difference in smiling between the 2 major party candidates. Joe Biden has a big toothy smile and Donald Trump keeps an old-time-y grumpy face much of the time. It's the Winston Churchill-type face. Trump speaks humorously more than he actually smiles, and his smiles are often just crooked, sly expressions, reactions to particular things that he's finding funny. His standard presentation is quite stern:



Some people experience that as threatening. For others, it works. But why? We may still have the feelings that led politicians before the Kennedy Era to present us with a sternly serious face.