Bae Sung-jin, a 30-year-old office worker, says there’s now one more way to check compatibility during blind dates.

“I get emotionally drained easily and tend to be very sensitive in relationships. So I make sure to check their MBTI and whether they’re a 'teto' or 'egen' type,” he said.

Twenty-two-year-old Lee, who recently got into so-called “identity tests,” introduced herself as follows: “I’m an ‘egen woman,’ so feminine clothing suits me well. But my personality is more like a ‘teto woman.’ — I’m bold and outgoing.”

A new personality classification trend has taken hold among young singles in Korea, with the rise of the “teto-egen” test. The test uses analogies to testosterone and estrogen levels to analyze interpersonal styles and energy types. Social media platforms like Instagram and YouTube Shorts are awash with users sharing their results.

The trend has spilled into pop culture as well. Young K-pop fans analyze celebrities based on the theory: Aespa’s Winter is labeled a teto woman, Karina an egen woman, Suzy a teto woman and IU an egen woman. Countless videos and comment threads speculate about celebrities’ personality types by combining their clothing style, speech patterns and dating histories.

Hormonal archetypes go viral

The “teto” and “egen” arcetypes are derived from the hormones testosterone and estrogen, respectively. According to the typology, a teto man is masculine and athletic, while an egen man is gentle and appearance-conscious. A teto woman is expressive and extroverted, whereas an egen woman is reserved and traditionally feminine.

The teto-egen test from the personality test platform, Types, had attracted over 1.16 million participants as of Thursday. The test, consisting of 28 questions, produces results such as gentle egen man or commander-like teto woman.

One of the main draws of this test is its romantic compatibility analysis. Emotionally sensitive egen men are said to be attracted to charismatic teto women, while strong-willed teto men are seen as well-matched with caring egen women.

The test gained even more attention after the final episode of “SNL Korea” season 2 on Coupang Play last month featured a skit titled “When a Teto Man Falls in Love.”

In the episode, boy group BTOB’s Yook Sung-jae, cast as an egen man, is dumped by his teto girlfriend for a more masculine partner. He undergoes a brutal teto transformation that includes growing a thick beard.

The origin of the trend dates back to June 2021, when a diet content creator first posted about it on his blog. It gained popularity through a web cartoonist on Instagram, going viral soon after.

For Gen Z, who seek quick ways to define themselves, the trend is a form of self-expression. Online content now covers dating, marriage, fashion, beauty and workplace behavior based on these archetypes.

One beauty YouTuber posted a makeup tutorial titled “Makeup for egen women,” featuring a clean and neat look. There are also countless videos on topics like “The ideal woman for an egen man,” “How teto women talk to teto men” and “How teto women date egen men.”

History of typing the self

Self-categorization trends are nothing new. In the late 1990s and early 2000s, blood types were a popular personality metric in Korea and Japan. Statements like “type A people are timid” and “type B people are selfish” were commonly accepted, even though they originated in racially motivated studies by a Japanese eugenicist that have since been rejected by scientists.

Later, the Myers-Briggs Type Indicator, or MBTI, became the most popular personality clasification tool, dividing people into 16 types. People began using MBTI types to explain themselves in conversations and check compatibility on first dates. It even found its way into career planning and hiring processes.

Professor Lim Myung-ho of Dankook University’s Department of Psychology and Psychotherapy explains the popularity of such trends as rooted in a desire for self-discovery and understanding.

“The trend reflects the MZ generation’s effort to understand themselves and build positive relationships with others,” he said.

Curiosity or confinement

In a nationwide survey by Embrain Trend Monitor involving 1,000 Koreans aged 19 to 59, 76 percent of respondents in their 20s and 71.6 percent in their 30s said they “want to understand themselves accurately.”

The 86 percent of those in their 20s and 87.6 percent of those in their 30s said they were “curious about who they are,” yet only 22.4 percent and 36.8 percent, respectively, felt they had truly learned about themselves through experience. The results highlight a growing reliance on type-based classifications to explore identity and match behavior to social expectations.

In essence, these tests are light-hearted forms of entertainment, but they also serve as tools for introspection, self-expression and social communication.

“In an anxious society, it reflects a desire to feel a sense of belonging and create intimacy in relationships,” said Lim. “As long as the intense competition among young people continues, these types of classification trends will persist.”

However, some experts caution that such identity tests risk reinforcing oversimplified binaries. Framing behavior and traits in terms of gendered hormones can make stereotypes further entreched.

“Humans are wired to categorize and group things. Just like with MBTI or blood types, categorizing people into ‘teto men’ or ‘egen men’ is another attempt to simplify complex human nature,” said Kwak Geum-joo, a professor of psychology at Seoul National University. She warned that while such classifications begin as curiosity, they can become self-restrictive if taken too seriously.

Professor Lim echoed the concern, “Blindly believing in these tests can lead to overgeneralization and binary thinking. Identity tests should be treated lightly and used for reference only,” he said.