I have two versions of myself. There’s English Elyar, who is direct, makes quick decisions, says "no" without guilt, and splits restaurant checks without thinking. Then there’s Farsi Elyar, who uses three sentences where one would do, insists on paying the entire bill, and physically cannot end a phone call with his mother in under 40 minutes.
These aren’t personality quirks. This is the bilingual brain doing exactly what research says it does: running different cognitive software depending on which language is active.
If you’re a Farsi-English bilingual. heritage speaker, advanced learner, or somewhere in between. you’ve probably felt this. You’re not imagining it. The science backs you up, and the implications go far deeper than you think.
The Personality Switch Is Real
Nairán Ramírez-Esparza and her colleagues at the University of Connecticut ran a study that made bilinguals take the Big Five personality test twice. once in each language. Same people, same questions, different language. The results weren’t subtle.
Bilinguals scored higher on agreeableness, conscientiousness, and extraversion when tested in the language associated with those cultural traits. Spanish-English bilinguals were more agreeable in Spanish. English made them more assertive.
For Farsi-English bilinguals, the pattern maps onto what every Iranian kid who grew up in the West already knows:
In Farsi: More formal. More emotionally expressive. More family-oriented. More indirect. More likely to use ta’ârof strategies. hedging, deflecting, performing modesty.
In English: More direct. More individualistic. More comfortable saying no. More likely to state opinions without the ritual softening that Farsi demands.
This isn’t acting. fMRI studies show that different neural networks activate depending on which language a bilingual is processing. You’re not performing a different personality. your brain is literally running different software.
Moral Decisions in Your Second Language
Boaz Keysar’s lab at the University of Chicago presented bilinguals with the trolley problem. the classic moral dilemma where you can pull a lever to divert a train, killing one person to save five. They tested people in their native language and in their second language.
The result: people were significantly more willing to pull the lever in their L2. More utilitarian. More coldly rational.
Why? Albert Costa and his team explained it through emotional distance. Your native language is wired into your emotional circuits. you learned it as a baby, soaked in the emotions of your childhood. Your second language sits one step removed. The words carry meaning but less emotional weight.
For Farsi-English bilinguals, this creates a strange split. Emotional content. love, grief, anger, family drama. hits harder in whichever language you experienced those emotions in. If your parents fought in Farsi, conflict feels more intense in Farsi. If you went through your first breakup in English, heartbreak lives in English.
This explains why heritage speakers sometimes describe a bizarre experience: they can discuss deeply personal topics more easily in English (less emotional activation) but feel things more intensely in Farsi (deeper emotional encoding) even when they lack the vocabulary to express it.
Memory Lives in Language
You remember events better in the language they happened in. This isn’t a theory. it’s one of the most replicated findings in bilingual cognition research.
Aneta Pavlenko, whose book The Bilingual Mind is the definitive reference here, documented bilingual subjects who could recall childhood memories in rich detail when prompted in their L1 but drew blanks when asked about the same events in L2. The memories were there. The language was the key that unlocked them.
For Iranian immigrants and their children, this creates layers:
- Grandma’s kitchen in Tehran? Those memories are in Farsi. English can describe them but can’t fully access them.
- High school in Los Angeles? Those memories are in English. Farsi might tag them with emotion but can’t reconstruct the details.
- The phone call from Iran where someone died? That memory is locked in whichever language delivered the news, and switching languages dulls the edges.
Active recall. the study technique of retrieving information from memory. works best in the language you encoded the information in. If you learned a Farsi word in an English context, you’ll retrieve it best through English cues.
Heritage Speaker Grief
This section is for the kids who grew up understanding Farsi perfectly but answering in English. Who can follow an entire family argument but can’t participate. Who feel something shift inside them when they hear a Persian song but can’t explain what.
Heritage speakers of Farsi occupy a unique cognitive position. They have the emotional wiring for Persian. the sounds, the rhythm, the affective associations. but lack the productive vocabulary to use it. It’s like having a fully built engine with no ignition key.
Pavlenko’s research describes this as "emotional attrition without linguistic attrition." The emotions stay. The words fade. A heritage speaker might feel the full weight of دلتنگی (deltangi). that specific blend of heart-narrowing, homesickness, and missing. but reach for it and find only "I miss home." The English approximation captures maybe 60% of what they’re feeling.
This isn’t sentimentality. It’s a measurable cognitive phenomenon. When heritage speakers regain productive Farsi skills, they consistently report that certain emotional states become "available" again. as if a dimmer switch got turned back up.
Code-Switching Is Intelligence, Not Confusion
If you’ve ever been told you’re "mixing up your languages" or that code-switching means you don’t speak either language well. ignore that. The research says the opposite.
Code-switching. alternating between Farsi and English within a conversation, sometimes within a single sentence. requires sophisticated cognitive control. You’re maintaining two active grammatical systems, monitoring the listener’s language competence, selecting the most precise word regardless of which language it comes from, and doing all of this in real time.
Studies show that habitual code-switchers have better executive function. they’re faster at task-switching, better at filtering irrelevant information, and more cognitively flexible than monolinguals. The bilingual brain isn’t confused. It’s overclocked.
Farsi-English code-switching is particularly common in diaspora communities because the two languages serve different social functions. English handles the professional, the technical, the institutional. Farsi handles the emotional, the familial, the culturally specific. Switching between them isn’t a failure of either language. it’s an optimization.
من امروز یه meeting داشتم. man emruz ye meeting dâshtam. "I had a meeting today." The English word "meeting" stays because the Farsi equivalent جلسه (jalse) implies something more formal than the casual work meeting being described. The code-switch is a precision choice.
What This Means for Learners
If you’re learning Farsi as a second language, the bilingual brain research has practical implications:
Emotional depth takes time. You’ll understand Farsi words long before they carry emotional weight. Del-compounds will be vocabulary items before they become felt experiences. This is normal. Costa’s research suggests emotional encoding in L2 deepens with immersion and emotionally significant experiences in that language.
Think in Farsi, don’t translate. Every time you construct a Farsi sentence by first thinking in English, you’re running it through your English cognitive framework. The personality switch research suggests that the more you can stay in Farsi-mode. thinking, feeling, reacting in Persian. the more natural your speech will become.
Your Farsi self will surprise you. You might find yourself being more polite, more indirect, more emotionally expressive in Farsi than you are in English. That’s not you being fake. That’s the language activating its cultural framework.
When you learn Farsi, you’re not adding a translation layer. you’re building a new self. ZabanYar was designed for this: not just vocabulary cards, but the cultural context that lets you think in Farsi, not just speak it.
For the full Sapir-Whorf framework applied to Persian, see the hub post. And if the diglossia problem. two registers of the same language. isn’t enough, now you’re dealing with two languages, two selves, and one brain trying to run it all.