If your cat looks at you, half-closes her eyes, and slowly opens them again, you have just received one of the clearest friendly signals in the feline repertoire. Behavior researchers call it the slow blink sequence, and cat lovers have long nicknamed it the cat kiss. Here is what the gesture means, what science found when it finally tested it, and how you can answer it.
What a Slow Blink Actually Looks Like
The slow blink is not a single blink. It is a sequence: a series of half-blinks, where the eyelids drift toward each other without fully closing, followed by either a prolonged narrowing of the eyes or a slow, complete closure. The whole thing takes a second or two, and it usually happens when your cat is relaxed, at a comfortable distance, and not asking for anything. That last part matters. A slow blink is offered freely, not as a demand for food or attention, which is exactly why behaviorists read it as genuine positive communication rather than a begging routine.
What the Research Found
In 2020, a team at the Universities of Sussex and Portsmouth published the first experimental test of the slow blink in the journal Scientific Reports. In their first experiment, cats were more likely to slow blink back at their owners after the owners slow blinked at them, compared with an owner sitting nearby and doing nothing. In the second experiment, an unfamiliar researcher slow blinked at cats she had never met, and those cats were more likely to approach the researcher’s outstretched hand afterward than when she kept a neutral expression. In other words, the slow blink is not just a happy-cat reflex. It works as a two-way signal, and it even works on strangers.
Why Cats Use It
Researchers offer two explanations, and both are plausible. First, cats may have simply learned that humans respond warmly to the gesture, so it pays off. Second, and more interesting, the slow blink may have started as a polite way to interrupt a stare. In cat social language, an unbroken stare is threatening; breaking eye contact with drooping eyelids says, in effect, I am relaxed and not challenging you. That fits what shelter workers notice every day: a cat who slow blinks from across the room is telling you that an approach is welcome.
How to Blink Back
- Soften your face first, the way you do just before a relaxed smile.
- Narrow your eyes slowly, then close them for two or three seconds.
- Open them gently and glance away; never hold a stare afterward.
- Keep your distance and let the cat decide whether to come closer.
- Try it during calm moments, not while the cat is eating, playing, or cornered.
The slow blink will not turn every cat into a lap cat. Some cats rarely offer it, and some respond to your first attempts with plain suspicion. But used consistently in calm moments, it is one of the cheapest and most reliable trust-builders an owner has, and it is a rare piece of cat body language that science has actually put to the test.