Barrett offers many other examples of variation between cultures; Utka Eskimos appear to have no clearly defined concept of anger, for instance, while Tahitians seem not to share our concept of sadness. We can also see how emotional concepts have changed throughout history. She points out that the ancient Greeks and Romans did not seem to smile spontaneously with big broad grins, for instance – suggesting that their expressions of pleasure and positive feelings could have been quite different from ours. (Apparently, the word smile does not even exist in Latin.) Instead, it appears that the smiles we recognise today – broad, toothy, and with crinkling at the eyes – only became more common in the 18th Century, as dentistry became more accessible.

As Mary Beard, a classicist at the University of Cambridge, puts it: “That is not to say that Romans never curled up the edges of their mouths in a formation that would look to us much like a smile; of course they did. But such curling did not mean very much in the range of significant social and cultural gestures in Rome. Conversely, other gestures, which would mean little to us, were much more heavily freighted with significance.”

Weathering the storm

This is not merely academic curiosity: Barrett’s book suggests some ways that we could all ride the tides of our emotions a little more wisely.

The fact that states like hunger, fatigue, or illness, all produce the same signals as emotions like anger, anxiety, sadness, or anxiety, emphasises the importance of looking after your body as a way to stabilise your mood. That can include things like a healthy diet and regular exercise, but Barrett also emphasises the importance of comforts like a good massage, which can reduce inflammation in the body. Such pleasures are not just luxuries – they may be a simple, practical way of keeping your mood in balance.

Mindfulness meditation, meanwhile, should encourage you to observe and deconstruct those bodily signals: understanding the physical origins of the emotions can help you to regulate the feelings. “Many things that seem unrelated to emotion actually have a profound impact on how you feel, because of the porous boundary between the social and the physical,” she says.

Barrett also emphasises the benefits of a good emotion vocabulary. As her work has shown, our emotion concepts are not hard-wired, but learnt – and some people have many more nuanced ways of reading their bodily signals and describing how they are making them feel in a particular context. Rather than simply describing yourself as happy, for instance, you may distinguish whether you are “blissful” or “inspired”; rather than just feeling “sad”, you might say you are “dejected” or “disappointed”.