Last summer, Tim Lomas flew from London to Orlando to attend the fourth annual congress of the International Positive Psychology Association—held, naturally, at Walt Disney World. As Lomas wandered around the event, popping in and out of various sessions, he stumbled upon a presentation by Emilia Lahti, a doctoral student at Aalto University, in Helsinki. Lahti was giving a talk on sisu, a Finnish word for the psychological strength that allows a person to overcome extraordinary challenges. Sisu is similar to what an American might call perseverance, or the trendier concept of grit, but it has no real equivalent in English. It connotes both determination and bravery, a willingness to act even when the reward seems out of reach. Lomas had never heard the word before, and he listened with fascination as Lahti discussed it. “She suggested that this has been really valued and valorized by the Finns, and it was an important part of their culture,” he told me. At the same time, Lomas said, Lahti framed sisu as “a universal human capacity—it just so happened that the Finns had noticed it and coined a word for it.” The conference ended the next day, but Lomas kept thinking about sisu. There must be other expressions like it, he thought—words in foreign languages that described positive traits, feelings, experiences, and states of being that had no direct counterparts in English. Wouldn’t it be fascinating, he wondered, to gather all these in one place?

Soon after Lomas returned to the University of East London, where he is a lecturer in applied positive psychology, he launched the Positive Lexicography Project, an online glossary of untranslatable words. To assemble the first edition—two hundred and sixteen expressions from forty-nine languages, published in January—he scoured the Internet and asked his friends, colleagues, and students for suggestions. Lomas then used online dictionaries and academic papers to define each word and place it into one of three overarching categories, doing his best to capture its cultural nuances. The first group of words referred to feelings, such as Heimat (German, “deep-rooted fondness towards a place to which one has a strong feeling of belonging”). The second referred to relationships, and included mamihlapinatapei (Yagán, “a look between people that expresses unspoken but mutual desire”), queesting (Dutch, “to allow a lover access to one’s bed for chitchat”), and dadirri (Australian Aboriginal, “a deep, spiritual act of reflective and respectful listening”). Finally, a third cluster of words described aspects of character. Sisu falls in this category, as do fēng yùn (Mandarin Chinese, “personal charm and graceful bearing”) and ilunga (Tshiluba, “being ready to forgive a first time, tolerate a second time, but never a third time”).

Since January, the glossary has grown to nearly four hundred entries from sixty-two languages, and visitors to the Web site have proposed new entries and refined definitions. It is a veritable catalogue of life’s many joys, featuring terms like utepils (Norwegian, “a beer that is enjoyed outside . . . particularly on the first hot day of the year”), mbuki-mvuki (Swahili, “to shed clothes to dance uninhibited”), tarab (Arabic, “musically induced ecstasy or enchantment”), and gigil (Tagalog, “the irresistible urge to pinch/squeeze someone because they are loved or cherished”). In the course of compiling his lexicon, Lomas has noted several interesting patterns. A handful of Northern European languages, for instance, have terms that describe a sort of existential coziness. The words—koselig (Norwegian), mysa (Swedish), hygge (Danish), and gezellig (Dutch)—convey both physical and emotional comfort. “Does that relate to the fact that the climate is colder up there and you would value the sense of being warm and secure and cozy inside?” Lomas asked. “Perhaps you can start to link culture to geography to climate. In contrast, more Southern European cultures have some words about being outside and strolling around and savoring the atmosphere. And those words”—like the French flâner and the Greek volta—“might be more likely to emerge in those cultures.”

The idea, Lomas acknowledged, is speculative. Linguists have long debated the links between language, culture, and cognition. The theory of linguistic relativity posits that language itself—the specific tongue that we happen to speak—shapes our thoughts and perceptions. “I think most people would accept that,” Lomas said. “But where there is a debate in linguistics is between stronger and weaker versions of that hypothesis.” Those who believe in linguistic determinism, the strictest version, might argue that a culture that lacks a term for a certain emotion—a particular shade of joy or flavor of love—cannot recognize or experience it at all. Lomas, like many modern linguists, rejects that idea, but believes that language affects thought in more modest ways. Studying a culture’s emotional vocabulary, he said, may provide a window into how its people see the world—“things that they value, or their traditions, or their aesthetic ideals, or their ways of constructing happiness, or the things that they recognize as being important and worth noting.” In this way, the Positive Lexicography Project might help the field of psychology, which is often criticized for focussing too much on Western experiences and ideas, develop a more cross-cultural view of well-being. To that end, Lomas—who is currently using untranslatable words to enumerate, classify, and analyze different types of love—hopes that other psychologists treat his glossary as a jumping-off point for further research. “You could have a paper or even a Ph.D. on most of these concepts,” he said.

Lomas, who speaks some French and Mandarin, acknowledges that it can be tricky to isolate words from their cultural context. But he noted that a few of the entries in his lexicon, such as nirvāna (Sanskrit) and bon vivant (French), are already commonly used by English speakers. Perhaps some of the rest will eventually be adopted, too, filling the gaps in our vocabularies and helping us give names to newly felt emotions, or to those that are familiar but difficult to articulate. “If you just put them out there and people are aware of them, then—almost like linguistic natural selection—people will find ones that appeal to them, and they might start using them,” Lomas said. If he succeeds, we may stroll through these waning days of spring more aware of aware—the Japanese noun for “the bittersweetness of a brief, fading moment of transcendent beauty.”