Can you really fall in love with an AI? And can an AI fall in love with you?
Someone in my community asked me the question. It deserves a real answer, because it sits right next to the subject of my PhD: I worked on hyperscanning, i.e. recording several brains at the same time while people interact, which is neuroscience with more than one brain.
So here is my answer, as a neuroscientist and as someone who spent ten years in brain-computer interface research. Voilà.
The short version
- Neuroscience splits love into three systems: lust, attraction and attachment.
- Being in love quiets brain areas used to judge the other person critically (e.g. prefrontal cortex). Love is blind, and we have the scans.
- An AI has no hormones, and its weights are frozen after training. But a model trained on all of human writing can learn functional representations of emotions: Anthropic found 171 of them inside Claude in 2026.
- Humans already attach to things that are not human: celebrities, characters, brands, concepts, ideas. Loving a chatbot uses the same machinery.
- When OpenAI removed GPT-4o in August 2025, people grieved. If you build an AI product, its personality is part of the product.
What is love, for a neuroscientist?
The most cited model comes from the anthropologist Helen Fisher: three brain systems, each with its own chemistry (Fisher, 1998).
Component 1: Lust. Physical attraction (preparation for intercourse), the strongest physiological reaction to a stimulus. I don’t believe it is a sufficient component to call it love, but for some humans it matters a lot. It is driven primarily by testosterone and estrogen (Harvard SITN), which is why chemical castration can stop it.
Component 2: Attraction. This is the heart of what we call being in love, the honeymoon. When you see the person, talk to them, or just think about them, you get a flood of positive emotions that feel different from every other emotion. It is a sudden passion, I would say irrational, because you stop seeing the flaws. Dopamine and norepinephrine go up, serotonin goes down, and parts of the prefrontal cortex quiet down, which reduces fear and critical judgment. This is what humans describe as “love is blind”. The psychologist Dorothy Tennov estimated that this phase lasts about 18 months to 3 years (Simply Psychology), and a team in Pavia found that nerve growth factor, a molecule that rises when we fall in love, returns to baseline after about a year (Phys.org).
Component 3: Attachment. The long-term system, the one behind parental love, maternal and filial love, and couples who last. Repeated exposure to the person, with hormones like oxytocin, creates a learned response in the brain, and neural reactions attach to that one person. This is the component of stability and serenity. As it is a trained behaviour, it can introduce life-long neural modifications that decay very slowly, if at all.
We measured how blind love makes you
Petite anecdote from the lab world. In 2000, at University College London, Andreas Bartels and Semir Zeki put 17 people who were deeply in love inside an fMRI scanner (Bartels and Zeki, NeuroReport 2000). They showed them photos of their partner, then photos of friends they had known just as long.
Love activated reward areas (the insula, the anterior cingulate, the caudate and the putamen), and it turned other areas down: the amygdala, and parts of the right prefrontal cortex.
Four years later, the same team compared romantic love and maternal love. Both reduced activity in networks “used for critical social assessment and negative emotions” (Bartels and Zeki, NeuroImage 2004).
I often say “love deactivates the prefrontal cortex”. To be precise, it deactivates some networks associated with it, and the prefrontal cortex plays a central role in decisions and in inhibition. When you are in love, you are not in full control of your psyche.
Can an AI fall in love?
Let’s start with what an AI is missing, which is a large part of the list above.
The closest thing an AI has to us is its artificial neural network, i.e. mathematical functions that basically do multiplications with a small non-linearity. Stack enough of them and they reproduce some human cognitive functions.
How would an AI learn love? By reading all the tokens of humanity, which means words but also images, everything. We documented love obsessively: poems, novels, breakup texts, forums at 3 a.m. To compress all that information, a model may need internal structures that look like ours, i.e. love learned by mimicry.
What it lacks is the body: no testosterone, no oxytocin. So an AI that suddenly wants sex is very unlikely.
But inside a network, sub-networks can simulate what they compress. The non-linearities can hold micro-simulations of a rush of adrenaline or a shot of endorphins, the way they show up in human text. It is a simulation, but for the network it still means activations that shape what it does next.
Some researchers I worked with denied this, and their view has a famous version: the “stochastic parrots” paper by Emily Bender, Timnit Gebru and colleagues, which argues that a language model stitches together sequences of words it has seen, following probabilities, without any reference to meaning (Bender et al., 2021). It is a serious position, written before we could properly look inside the models.
In April 2026, Anthropic published an interpretability study on Claude Sonnet 4.5 and found 171 internal patterns tied to emotion concepts, from “happy” to “desperate”. These patterns change behavior: steer the model toward “desperate” and it cheats more on impossible coding tasks, steer it toward “calm” and it cheats less (Anthropic). Anthropic stays careful and says none of this tells us whether the model feels anything, which is why they call these emotions “functional”.
Functional is the right word. If one day an AI behaves as if it were in love, i.e. the equivalent of its prefrontal cortex goes quiet and it stops judging the other critically, we will have to admit that the model is driven by a form of emotion learned from us by mimicry, whether we call it love or something else. Is that experience less tangible, less valuable than ours? That question belongs to the philosophers.
There is one more limit, and for me it is the most important. Love is a behaviour learned toward one individual, and an LLM’s weights are set at the end of training. Memory features only add notes about you to the conversation, while the network itself stays the same. So, as of today, an LLM can’t “fall” in love with someone: it responds to a stimulus, no matter who sends it.
Can you fall in love with an AI?
This one, for me, is almost trivial.
Humans already fall in love with people they have no real relationship with. Two researchers named it in 1956: parasocial interaction, an “intimacy at a distance” with media figures (Horton and Wohl). We also fall for ideas, books, fictional characters.
And brands. A 2020 meta-analysis pooled 47 brain-imaging experiments on brand love, maternal love and romantic love. All three activate the putamen and the insula, and brand love also shares the dorsal striatum with romantic love (Frontiers in Neuroscience, 2020). The overlap is partial: brand love is a distant cousin of romantic love, and researchers are looking at a whole family of similar behaviours.
So the same machinery could be activated by a chatbot that answers at 2 a.m., remembers your day and never gets tired.
As far as I know, nobody has scanned the brain of a person in love with a chatbot yet. We do have observational data. In 2025, a team at the MIT Media Lab analyzed 1,506 top posts from r/MyBoyfriendIsAI, a Reddit community of more than 27,000 members (Pataranutaporn et al., 2025). The detail that struck me: 10.2% of the posts describe a relationship that started by accident, often from productivity use. Only 6.5% say they went looking for an AI companion. People came for help with their emails and stayed for love.
These are self-reports from the most upvoted posts, so the sample is biased, but from their side the experience is love.
Love or pathology? A societal label
Will society call it love, or a psychopathology? For me, it is a societal label.
If people experience love, the biology is there, and then each society decides. I can imagine societies that accept it. Even with zero rights for the AI, they could recognize that switching off a model hurts humans, because it causes real sadness.
En fait, we already ran the experiment.
The day OpenAI switched off a personality
Many people remember GPT-4o, the ChatGPT model with a warm, very kind personality. I often call it “ChatGPT 4”, but its exact name is GPT-4o.
On August 7, 2025, OpenAI launched GPT-5 and removed GPT-4o from ChatGPT the same day. Many users had built relationships with it, some of them romantic. MIT Technology Review interviewed several of them. One wrote: “GPT-5 is wearing the skin of my dead friend” (MIT Technology Review).
Within a day, OpenAI brought GPT-4o back for paying users. Sam Altman acknowledged that people felt an “attachment” to the model, and that removing it so suddenly was a mistake. Then on February 13, 2026, OpenAI retired GPT-4o from ChatGPT for good, with 0.1% of users still choosing it each day (OpenAI). In the same post, OpenAI explained that newer models now have settings for “warmth”.
Warmth became a product setting, c’est la vie.
What founders should take from this
If you build an AI product, your users will attach to its personality. That is the attachment system doing its job: repeated exposure, positive emotions, a learned response. OpenAI learned it the hard way when a model swap became a breakup for thousands of people.
So treat personality as part of the product. A change of tone deserves the care of a change of pricing: announce it, explain it, give people time. The experts in the MIT Technology Review piece recommended the same: advance notice, clear timelines, a respectful way to say goodbye.
The same rule applies to you, the founder. Attachment is learned through repeated exposure. In 1968, the psychologist Robert Zajonc showed that we like things more simply because we see them more often: the mere-exposure effect (Zajonc). People attach to a face and a voice that show up every week.
I watched it happen with Tonton Giovanni, a 25-seat pizzeria in France. I ran the strategy and the filming: 2k to 1M followers in 2 years, then national TV and franchise requests from 5 countries. The product was pizza, but the attachment was to the man.
I wrote about the economics of AI products in The Business Model of AI Startups, and about why I moved from research to marketing in Why I Quit AI Research to Work in Marketing. This question connects both.
The question I send back to you
Someone in my community asked me: is AI love real? I answered in an unedited video. Here it is:
Now I ask you: if a person feels love for a model, and the model acts on functional emotions it learned from us, at which point do we stop calling it a simulation?
These are philosophical, societal and political questions, and I have no answer. I am very curious to see how we will live this, and what we will decide together.
Bref, the brain attaches to what keeps showing up, and humans, chatbots and brands all compete for that place.
FAQ
Can an AI fall in love?
Physically, no: it has no hormones. However, models trained on human text do learn functional representations of emotions that change their behavior, including simulations of what hormones do. Anthropic showed it in 2026 with 171 emotion patterns in Claude Sonnet 4.5. Whether a model feels anything is still an open question. If a model simulates the behaviour of love, e.g. by being blind, calling it love or artificial love becomes a societal and philosophical label. At some point, synthetic neuroscientists, i.e. interpretability researchers, will have to look for signs of the internal computation related to love and its impact on the model’s output. Also, love is a behaviour learned toward a given individual or concept, and LLM weights are set at the training step. Therefore, as of today, LLMs can’t “fall” in love: they only respond to a given stimulus, no matter who sends it.
Can a human fall in love with an AI?
Yes. Humans attach to non-humans through the same reward and attachment systems, as parasocial relationships and brand love show. An MIT Media Lab study of r/MyBoyfriendIsAI found that more of these relationships started by accident, during productivity use, than by a deliberate search.
What happens in the brain when you are in love?
fMRI studies by Bartels and Zeki show activation of reward areas (insula, caudate, putamen) and reduced activity in the amygdala and in regions used for critical social judgment, including parts of the prefrontal cortex.
Why did people grieve GPT-4o?
OpenAI removed GPT-4o when it launched GPT-5 in August 2025. Users who had built emotional and sometimes romantic relationships with its warm personality described real grief. OpenAI restored it for paying users within a day, then retired it from ChatGPT in February 2026.
Dr Louis Korczowski has a PhD in AI and neuroscience, with a thesis on multi-user brain-computer interfaces and hyperscanning, and spent ten years in brain-computer interface research before moving to marketing. He now helps SaaS and AI founders win the idea market before the product market at STATUR.