The couple met while on a social sciences masters' programme at the University of Chicago. Both now work at Whitman College in Walla Walla, Washington. Kim is a professor of sociology and Leavitt has an administrative role, having previously taught in the sociology department. So it is unsurprising that they shared this academic desire to explore the wider meaning of their attraction.
Along with Tiger Mom and her Jewish husband, perhaps the most famous current JewAsian couple is Facebook founder Mark Zuckerberg and his wife Priscilla Chan.
Zuckerberg was raised Jewish and had a barmitzvah but describes himself as an atheist, while Chan is a Buddhist whose parents came to America from Vietnam. The couple are famously private (despite the implicit irony there) and rarely talk publicly about their relationship.
Nonetheless, paediatrician Chan and billionaire tech superstar Zuckerberg are prime examples of Chua's "triple package". They are hardworking and successful, both professionally and, with the birth of baby daughter Max in 2015, personally.
Kim and Leavitt also noticed other Jewish Asian couples featuring in national newspapers, and saw the phrase JewAsian begin to grow. "We found the term was appearing a lot online," says Kim, "especially in reference to certain kinds of food - such as kimchee with latkes - on the one hand, and on the other hand, being used [by people of mixed backgrounds] to refer either to themselves or to their relationships.
"It's one of those terms that tends to appear right after a hashtag."
The idea of a younger generation appropriating a mixed-race identity and translating it into something accessible for the social-media generation is an idea that figures prominently in much of Kim and Leavitt's research. They interviewed 34 couples as well as the children of Jewish Asian couples. "We noticed that when a millennial JewAsian got a question such as 'are you half-Jewish?', the young people responded with a confidence and real understanding.
"In some ways, we went into this project thinking that there would be a certain amount of stress or conflict [between the two identities] but none of that played out. We were amazed by how much 'Jewish' there was, in a variety of ways - study, synagogue affiliation - it was very hopeful."
Their research found that culturally, it was Judaism that tended to shape the home-life of these couples.
"There is an understanding that the key value systems have an overlap that gets played out in Jewish practice," says Leavitt. Kim attributes this mainly to the fact that the Asian partner in JewAsian relationships is usually second- or third-generation immigrant.
"They are removed from the ethnicity of their parents' or grandparents' household," she says. "Some of them had less of a sense of how to bring an Asian ethnicity into the realm of a household." Judaism, however, retains a firmer hold.
Combine that, Kim continues, with the breadth of resources available to the Jewish community - shuls, community centres, texts - and "this organisational aspect makes the instilment of Judaism more accessible."
However, the outside world tends to identify the children of these pairings at least, with the Asian community.
Kim and Leavitt have two children, Ari, 8 and Talia 5. "We wanted to give them Hebrew names so they knew they would always be Jewish," explains Kim, "no matter what people assumed or how they presented to the world, because they look more racially Asian."
London couple Sani and Mike Jackson agree that a shared sense of family values is the main similarity between Jewish and Asian cultures. It's certainly the glue in their relationship.
"From a Taiwanese perspective, family is really important," says Sani. "Previous partners have struggled with that but Mike's Jewish background really helps. There are a lot of shared values and his family is really close, too."
She says that her mother was concerned about her marrying a "Westerner" - "She always used to say to me 'your future partner might not accept the way that we are'. But she sensed it [was different] the first time she met Mike's parents." They also have "similar world views". Mike works in his family business and Sani, who works for Deloitte, says that this "element of being self-sufficient and working hard [is] stereotypically Jewish and Chinese."
Sani and Mike say that they are "lucky" - both of their families "have been tolerant" of their relationship. And while "tolerant" might not seem the most positive word, the details of their life together reflect an elegant combination of two cultures.
Their wedding last September brought together elements from both their backgrounds, including the breaking of the glass and sheva brachot along with a traditional Chinese tea ceremony and fan throwing.
However, reflecting Kim and Leavitt's findings that Judaism often becomes the dominant religious influence in JewAsian households, Sani and Mike are planning on circumcising their first child if it is a boy (Sani is currently pregnant) and the couple currently hold Friday-night dinners, keep Pesach and go to shul for Rosh Hashanah. Sani also says that she's keen for her children to get a Jewish education. "I want Mike's brother, who is more religious, to teach our kids how to be Jewish. I want them to know how to do things properly."
Sani says that she does not personally know other British JewAsian couples, but is aware of a number of Chinese/Jewish relationships across the pond: "A lot of my mum's friends who have emigrated to America have married Jewish people," she says.
Kim and Leavitt's research hasn't extended outside the US but Leavitt did think a big factor in the number of JewAsian relationships was that "they tend to be Reform Jews". Reform Judaism is the largest denominational branch in the US, and represents around 20 per cent of Jews in the UK. In 1983, the Reform Movement in the US made a landmark decision to accept patrilineal descent, allowing Judaism to be passed down by the father alone.
This means that the children of interracial couples can "authentically identify" themselves as Jewish, regardless of whether the Jewish spouse is the man or the women.
Kim says: "In terms of the larger cultural and social trends in the US, we're in an age where being more than one thing - racially, ethnically - is seen as being 'cool'.
"Part of that has to do with the fact that, in the 2000 census, individuals were given the option to self-identify as more than one race. The choice of picking everything that you think you are trickles down into how people see themselves and the kinds of attitudes that prevail."
It was this shift towards more relaxed attitudes that led Kim to convert to Judaism in 2015 – 13 years after marrying Leavitt in a predominantly Jewish wedding ceremony. "I had been thinking about conversion for decades, before Noah and I met, even," says Kim. "There was something I just wasn't comfortable with about conversion but I decided to do it when I saw myself reflected in the American Jewish population.
"There's much more attention being paid to the racial and ethnic diversity of American Jews and that was the tipping point for me."
(University of Nebraska Press, £26.95)
