We treat the smile as if it can cover anything. We believe that if we curve our lips upward, the feeling underneath stays hidden and no one is the wiser. The truth is more interesting than that. A genuine smile and a social, put-on smile are not even produced by the same machinery in the brain — they are controlled by two completely different systems. That is why one can be faked on demand and the other cannot.

Two smiles, two parts of the brain

The smile we manufacture for a photograph or a polite moment is a voluntary movement. We decide to do it. The smile that arrives when something genuinely delights us is involuntary — it happens to us before we choose it. This is why a posed smile so often looks slightly off, and why a real one is hard to summon on command when the feeling isn't there. The lips can be instructed. The rest of the face is harder to direct.

The clearest marker of a true smile lives in the eyes, not the mouth. When the smile comes from somewhere real, the lips stretch wide and the eyes narrow at the same time — the cheeks lift, fine lines gather at the outer corners, and you can actually see the smile reach the eyes. When the smile is only social, the mouth does all the work and the eyes stay flat and uninvolved.

Slowing down Deepika's smile

I took one of Deepika Padukone's videos — the kind we all enjoy watching — and ran it in slow motion to read it frame by frame. For most of the clip she is smiling, and it reads warmly enough at full speed. But slow it down and watch the moment her smile forms, and something specific happens: her nose shrinks. There is a small wrinkling and pulling-in around the nose.

That detail matters. A wrinkle across the bridge of the nose is one of the recognised signals of disgust, not joy. When it appears underneath a smile, what you are usually seeing is a smile placed on top of another feeling — a pleasant expression masking a flicker of something she would rather not show. The cheeks aren't doing the lifting, the eyes aren't doing the narrowing in the genuine way; the mouth is performing while the nose quietly tells a different story.

What this actually tells us

I want to be careful here, because reading one cue is not the same as knowing someone's mind. A nose wrinkle in a single clip doesn't make a person dishonest or unhappy. It tells us that in that particular moment, the smile was managed rather than felt — which is something every public figure does constantly, for very ordinary reasons. Cameras, attention and expectation will make anyone reach for a controlled smile.

So when you train yourself to spot the difference, look for these things together:

  • Do the eyes narrow and crease at the same time as the lips stretch, or is the mouth working alone?
  • Do the cheeks lift naturally, lifting everything above them?
  • Is there any nose-wrinkling, lip-pressing or other movement that belongs to a different emotion entirely?

A real smile is a whole-face event. A fake one is a local one. Once you start watching for the eyes and the nose instead of only the mouth, you cannot un-see it — in celebrities, in colleagues, and quite humblingly, in yourself. That is the gift and the discomfort of learning to read faces: the smile stops being something you can fully hide behind.