Dolphins are considered to be one of the most intelligent creatures on Earth, and it has long been suggested that dolphins are incredibly social creatures who form deep connections with one another and exhibit intricate social dynamics. New research even indicates that dolphins may potentially ‘smile’.

Dolphins frequently exhibit open-mouthed facial expressions, often considered to be ‘smiles’. Although they are often interpreted positively, there has been limited research into the role of facial communication in dolphins. Much is still unknown about how dolphins use these expressions in social interactions and what they might convey about their inner thoughts and emotions.

[…] there were around 1300 instances of ‘smiles’.

Researchers from the University of Pisa – Elizabetta Palagi and her colleagues – recently examined the behaviour of 22 captive bottlenose dolphins (Tursiops truncatus) at two wildlife parks: Planète Sauvage in Port-Saint-Père, France and Zoomarine in Rome, Italy. Their aim was to explore this knowledge gap and try to answer the question: do dolphins really smile?

The researchers observed 80 hours of footage – nearly 900 play sessions among the dolphins. Within this they found that there were around 1300 instances of ‘smiles’. About 90% of the time, these occurred when the dolphins were in view of one another. Furthermore, most of these ‘smiles’ occurred during play with other dolphins, and rarely alone. These aspects of the research indicate dolphins are highly social: these ‘smiles’ could give us a huge insight into their social lives.

One significant finding of the study was that a dolphin expressed this open mouth ‘smile’, often within a second, another dolphin reciprocated. In this study, 33% of the time the dolphins appeared to ‘smile’ back. In humans, a similar rapid mirroring tends to occur, and this parallel may extend further than the physical gesture. When humans mimic one another, it is generally unconscious, and vital to non-verbal communication. A smile, for instance, can be an instinctive response to another person smiling. This is very important for interpersonal connection, empathy and emotional bonding. It takes just milliseconds to recognise a facial expression and reciprocate.

It’s a step forward in understanding the social dynamics of dolphin, but not everyone is convinced.

Smiling amongst humans has been well researched and understood to have these social links, but the research into similar instances within a completely different species is fascinating. It is an area which will require a great deal of further research to completely determine what is behind the smile of a dolphin. To distinguish between playfulness and a myriad of other emotions in these creatures is very complicated.

About her research, Palagi said the open-mouthed expressions were a ‘very sophisticated form of communication’. It’s a step forward in understanding the social dynamics of dolphins, but not everyone is convinced. Heather Hill, professor of psychology at St Mary’s University in Texas, is sceptical. She said, ‘I do think that the dolphins engage in an open-mouth response during play situations, and it […] does seem reasonable that it is a form of communication […] I’m not comfortable calling it a smile, because they also use the open-mouth displays in a lot of other contexts’. 

Despite this, Palagi remains convinced that the open mouth is specific to playful contexts. In her study, when the dolphins were aggressive or anti-social, her and her team did not observe these ‘smiles’. She recalls that ‘During the few aggressions we witnessed, we saw the opening of the mouth, but after this extremely rapid opening, either a bite or an attempted bite followed’.

There remains no certain answer on this topic, however, I think Elizabetta Palagi proposing a smiling community of social dolphins is a lovely image, and an optimistic look into the animal kingdom.

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