What having a cat does to your brain (and theirs)

Laura Elin Pigott For The Conversation

London: Petting a cat, hearing it purr is not trivial: behind these moments lies a chemical reaction that strengthens confidence and reduces stress, both in humans and animals.

While cats may have a reputation for being independent, recent research suggests we share a unique bond with them, fuelled by brain chemistry.

At the heart of the process is oxytocin , often referred to as the "love hormone." This same neurochemical is released when a mother cradles her baby or when friends hug; it has a beneficial effect on trust and affection . And now, research indicates that it also plays an important role in the relationship between cats and humans.

Oxytocin is central to social bonding—the ability to connect with and trust others—as well as stress regulation in both animals and humans. A 2005 experiment showed that it made human volunteers significantly more likely to trust others in fictitious stock market transactions.

This hormone also has calming effects in both humans and animals: it reduces cortisol, the stress hormone, and activates the parasympathetic nervous system—the rest and digestion system—to help the body relax .

Scientists have long known that friendly interactions between dogs and their owners trigger the release of oxytocin , creating a true emotional feedback loop. But in cats, this phenomenon has been less studied.

Less demonstrative than dogs, cats express their affection in more subtle ways. Yet, their owners often describe the same benefits: warmth, comfort, and reduced stress. Research is gradually confirming these reports. For example, Japanese researchers showed in 2021 that brief petting sessions with a cat increased oxytocin levels in many owners.

In this study, women spent a few minutes interacting with their cats while scientists measured their hormone levels. The result: friendly contact (petting, speaking softly) led to an increase in oxytocin in their saliva.

Many people find petting a purring cat soothing, and it's not just about the softness of the fur. Simply petting a cat—or even hearing one purr—stimulates the production of this hormone in the brain. A 2002 study showed that this touch-triggered surge of oxytocin helps lower cortisol, which can then lower blood pressure and even pain.

When does oxytocin circulate between cats and humans? Researchers are beginning to identify the precise moments that trigger this bonding hormone in the human-cat relationship. Gentle physical contact appears to be the main factor.

A study published in February 2025 shows that when owners caress, cuddle, or rock their cats in a relaxed manner, their oxytocin levels tend to increase, just like those of felines, provided the interaction is not forced.

The researchers monitored the cats' oxytocin levels during 15 minutes of play and cuddling at home with their owners. When the cats initiated contact, such as sitting on their laps or headbutting, they showed a significant increase in oxytocin. The more time they spent with their humans, the greater the increase.

What about less cuddly felines? The same study noted different patterns in cats with more anxious or distant attachment styles. So-called "avoidant" cats, who keep their distance, showed no significant change in oxytocin levels, while anxious cats (always seeking their owner, but quickly overwhelmed) had high oxytocin levels from the start.

In both the latter and the avoidant cats, forced cuddles lowered oxytocin levels. In other words, when the interaction follows the cat's rhythm, the bond deepens; when it is forced, the attachment hormone decreases.

Humans could learn a lesson from this: the key to creating a strong bond with a cat is understanding how it communicates.

Unlike dogs, cats don't rely on prolonged eye contact to bond. They use more subtle signals, such as slow blinking—a "cat smile" that conveys security and trust.

Purring also plays a central role. Its low-pitched rumble is associated not only with self-healing in cats, but also with calming effects in humans . Listening to it can reduce heart rate and blood pressure, and oxytocin contributes to these benefits .

So, the company of a cat—reinforced by all those little bursts of oxytocin from interactions—can act as a real shield against stress, anxiety, and sometimes even depression, offering comfort in some cases close to that of human support.

Are cats less affectionate than dogs? Indeed, studies show that oxytocin is generally released more strongly during human-dog interactions. In a famous 2016 experiment , scientists measured oxytocin in pets and their owners before and after ten minutes of play. Dogs showed an average increase of 57 per cent after play, compared to about 12 per cent in cats.

In humans, too, oxytocin levels rise more when social interactions are strong. Studies show that contact with a loved one produces stronger oxytocin responses than contact with strangers. This explains why a dog's enthusiastic greeting can resemble the emotion felt when receiving a child or partner.

Dogs, pack animals domesticated to live alongside humans, are virtually hardwired to seek eye contact, petting, and approval—all behaviours that stimulate oxytocin on both sides. Cats, on the other hand, are descended from solitary hunters and haven't developed the same demonstrative social signals. As a result, they release oxytocin less frequently, often only when they feel safe.

A cat's trust isn't automatically acquired; it's earned. But once acquired, it's reinforced by the same molecule that unites human parents, partners, and friends.

So the next time your cat blinks gently from the couch or curls up and purrs in your lap, remember: something more than just tender is happening. Oxytocin is circulating in both of your brains, building trust and easing stress. Cats, in their own way, have figured out how to activate the chemistry of love in us.

The author is Senior Lecturer in Neurosciences and Neurorehabilitation, Course Leader in the College of Health and Life Sciences, London South Bank University