Does your personality change when you speak another language?

Ask a room of multilingual people whether they feel like a different person in each language, and most of them will say yes. Ask them what exactly changes, and the answers become vague: more confident in one, quieter in another, funnier in a third.

There are two views. One holds that your personality stays the same and only the circumstances change. The other holds that a language brings its own way of behaving and thinking with it. The research supports a position between the two, closer to the first: the feeling is real and common, and the measurable change is small.

What the research says

Three lines of research are quoted most often. They measure different things, so it helps to keep them apart.

Study	What was done	What it found	Limits
Ramírez-Esparza and colleagues, 2006	Spanish and English bilinguals in the US and Mexico filled in the same personality questionnaire in both languages	Slightly higher scores for extraversion, agreeableness and conscientiousness in English, in three separate samples	Small differences, self-report only, one language pair
Dewaele, 2016, building on a survey by Dewaele and Pavlenko	1,005 bilinguals and multilinguals were asked whether they sometimes feel like a different person in their different languages	A majority said yes	Self-selected, highly educated respondents; it measures a feeling, not behaviour
Keysar, Hayakawa and An, 2012	Students made decisions about risk in their native or a foreign language	Classic framing effects and loss aversion shrank in the foreign language	Later replications are mixed and the effect is small

Cultural frame switching

The 2006 study, published in the Journal of Research in Personality, is the source of the headline "bilinguals have two personalities". Its authors did not claim that. They called the effect cultural frame switching: a language acts as a cue for the culture you associate with it, and you shift a little towards that culture's norms.

The shifts matched the differences between English and Spanish speakers in general, and they were modest. People kept their rank within the group: someone more outgoing than the others in Spanish was also more outgoing than the others in English. A later study by Chen and Bond with Chinese and English bilinguals in Hong Kong added a useful detail. It was not only the language that mattered, but also who the person was talking to and what they believed about the typical speaker of each language.

Feeling different

Jean-Marc Dewaele has spent years on the emotional side of multilingualism. In his 2016 paper he tested the obvious explanation, that people feel different because they learned the language late or speak it less well. The data did not support it: neither age of learning nor self-rated proficiency predicted the feeling. What did correlate was education, age and anxiety about speaking the foreign language in certain situations, such as on the phone.

Earlier, the anthropologist Michele Koven recorded bilingual daughters of Portuguese migrants in France telling the same personal stories in both languages. They came across as different characters in French and in Portuguese, to themselves and to listeners. The self that others see is partly made of the speaking styles a language offers you.

The foreign-language effect

Keysar's team at the University of Chicago found that well-known decision biases weakened when people worked in a foreign language. Their explanation was distance: a foreign language carries less emotional charge, so choices become cooler.

Treat this one with care. Two meta-analyses, in 2021 and 2022, found the effect to be real but small, some individual attempts have failed to reproduce it, and the results in moral dilemmas are inconsistent. It also describes a decision made in the moment, not a trait. It does not show that you become a more rational person in Japanese.

Do bilinguals have two personalities?

No. The careful summary is one personality with several settings.

Everybody already behaves differently with a grandmother, a manager and old friends, and nobody calls that three personalities. A second language adds another context, with its own audience, its own rules and its own history in your life. What people report as a change of personality is mostly a change of situation, culture and confidence.

Kungfucius has put the question to a good number of polyglots over the years. Most say that something shifts, and several add at once that "personality" is the wrong word for it. That is anecdote, not evidence, but it agrees with the studies.

Why you feel different in another language

Politeness is built into the grammar. Japanese and Korean make you choose a level of respect in nearly every sentence. You cannot say "I went" without deciding how formal you are being and to whom. Speakers of these languages as a foreign language often feel more careful and more polite, because the language keeps asking.

Directness has other rules. Chinese can sound blunt to Europeans in some places, such as plain questions about salary, age or weight, and very indirect in others, such as refusals, where saving face matters. Following those rules feels like being someone else. It is only being appropriate.

Humour is the last thing to arrive. With a small vocabulary you cannot be ironic, quick or precise. Many learners feel duller and more agreeable in a foreign language for exactly this reason. The opposite also happens: mistakes are forgiven, embarrassment weighs less, and some people become bolder than they are at home.

You sound like the people you learned from. If your Chinese came from one teacher, a partner or one group of friends, you have borrowed their vocabulary, their tone and their jokes. Learners who picked up a language from television sound like television.

Emotional weight differs. Dewaele's surveys show that swear words and declarations of love usually feel strongest in the first language. A foreign language can make hard things easier to say, sometimes easier than they should be.

Examples from Chinese, Japanese and Korean

Term	Reading	What it means for how you behave
敬語	keigo	Japanese honorific language: respectful, humble and polite forms chosen according to who you are talking to and about
空気を読む	kūki o yomu	"Reading the air": sensing what is expected without being told. Good Japanese starts with listening
존댓말	jondaenmal	Polite speech in Korean, used with strangers, elders and seniors
반말	banmal	Casual speech in Korean, for close friends and younger people. Switching too early is a real offence
눈치	nunchi	The Korean skill of noticing the mood and acting on it
客氣 (客气)	kèqi	Being polite and modest in Chinese, for example by declining an offer once before accepting
面子	miànzi	"Face": the reason a Chinese refusal often arrives as "let me think about it"

A learner of Japanese who becomes quieter and more attentive has not grown a new character. The language rewards listening, and the learner has noticed. The same person may turn louder and more talkative in Chinese, where a lively dinner table is a compliment to the host.

Your starting point matters too. Whether a language makes you feel more open or more reserved depends on what you are comparing it with, so two learners of the same language can report opposite changes.

Borrowing a voice: shadowing, echoing and chorusing

There is a practical side to all this. When you practise with shadowing, echoing and chorusing, you copy more than sounds. You copy a speaker's rhythm, pitch, pauses and manner. In Kungfucius's experience, some aspects of "personality" are transferred this way, and which ones depends on the language: the measured politeness of a Japanese announcer, the warmth of a Korean variety host, the directness of a Taiwanese podcaster. Choose your models with that in mind. You may end up sounding a little like them.

What learners can do with it

• Use the other self. A slightly different persona lowers the fear of speaking. If you are bolder in Korean than in your own language, good. Keep it.
• Choose your models. Since you will sound like the people you imitate, pick speakers you would like to resemble, and more than one. Shadowing is the direct way to borrow a voice.
• Learn the politeness layer early. It is part of the language, not decoration. The language and culture section of the skills guide explains where it sits.
• Check your strong statements. If a foreign language makes swearing, criticism or big promises feel light, remember that they land at full weight on a native listener.
• Expect your personality to catch up. The dull, agreeable beginner is a vocabulary problem. Humour returns somewhere in the intermediate stage.
• Keep the languages apart. If Japanese politeness starts leaking into your Chinese, that is language interference, and it has its own remedies.

A practical test: record yourself telling the same short story in two languages, and listen to both. You will hear the same person, wearing a different coat.