Slow Blink — Cat Behaviour Glossary

Slow blink

Slow blink — a feline affiliative signal in which a cat deliberately half-closes and slowly reopens its eyes, communicating relaxation and the absence of threat. Used between bonded cats and between cats and trusted humans. Scientifically confirmed to function as a positive social signal in a 2020 study published in Scientific Reports.

What it communicates

In cat-to-cat communication, a direct, unblinking stare is a threat display — it signals challenge or dominance. Deliberately breaking that stare by closing the eyes is a de-escalation signal: it communicates "I see you, I am calm, I pose no threat." The slow blink is the opposite of a hard stare.

Cats that feel safe and relaxed around a person often initiate slow blinks spontaneously. Owners frequently notice their cat looking at them from across the room and blinking slowly — and then looking away. This is an active social communication, not incidental sleepiness.

The research

Prior to 2020, the slow blink was described anecdotally in cat behaviour literature but had not been rigorously tested. The study by Humphrey, Proops, Forman, Spooner and McComb (2020) used two controlled experiments:

Experiment 1: Owners slow-blinked at their own cats in a familiar home environment, then held a neutral expression. Cats slow-blinked significantly more during the slow-blink condition.
Experiment 2: An unfamiliar experimenter slow-blinked at cats, then offered an open hand. Cats were significantly more likely to approach a slow-blinking experimenter than one with a neutral expression.

The results suggest the slow blink is understood cross-individually (not just between bonded pairs) and cross-species (humans can use it meaningfully with cats).

Try it. Look at your cat from a comfortable distance. Soften your gaze (avoid a hard stare), slowly half-close your eyes, hold, then slowly reopen. Look slightly away afterward. Many cats respond with their own slow blink within a few seconds — sometimes followed by approaching you.

Related signals

The slow blink sits within a broader set of feline affiliative signals. It is often seen alongside bunting (face-rubbing), relaxed tail posture, and vocalisation (trilling or soft chirping). All are signals of comfort and social positivity. For a full overview of how these signals fit together, see our cat body language guide.

Frequently asked questions

Is the slow blink scientifically proven?

Yes. A 2020 study by Humphrey et al. in Scientific Reports used two experiments to test whether cats slow-blink in response to humans who slow-blink at them. In both experiments, cats slow-blinked more and were more likely to approach a researcher who slow-blinked, compared to a neutral expression. The study also confirmed that cats slow-blink more when their owner initiates the signal than when a stranger does.

How do I do a slow blink correctly?

Make eye contact with your cat at a relaxed distance. Let your eyes go slightly soft (not a hard stare), then slowly half-close them — hold for one to two seconds — then slowly reopen. You can combine this with looking slightly away rather than maintaining a direct stare. Do not rush it; the slow pace is the signal. Many cats will respond within seconds.

What is the difference between a slow blink and a cat just being sleepy?

Context. A slow blink as an affiliative signal happens when the cat is alert and oriented toward a person or another cat. Sleepy eye-closing is accompanied by a generally drooping, relaxed body. In practice, the affiliative slow blink is often accompanied by a brief look-away afterward — the cat breaks the gaze after blinking, which is a deliberate de-escalation signal.

Can I slow-blink at a cat I don't know?

Yes — and it can be a useful trust-building tool. The same study found effects with unfamiliar researchers as well as owners, though the response was stronger with the owner. When approaching an unfamiliar cat, a slow blink combined with crouching to cat level and extending a hand low is a respectful greeting. International Cat Care recommends this approach for interactions with cats in shelters or rescues.

Do cats slow-blink at other cats?

Yes. Slow blinking between cats — particularly bonded pairs — has been observed as part of mutual affiliative behaviour, often alongside allogrooming and resting in contact. It appears to be a general relaxation and non-threat signal in feline social communication, not specific to human-cat interaction.