Cognitive Sciences Stack Exchange is a question and answer site for practitioners, researchers, and students in cognitive science, psychology, neuroscience, and psychiatry. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I've recently become aware of this - I kinda knew I was always doing it, but just now it got me self conscious and thinking about it:

When crossing paths with a stranger, you are supposed to be friendly and smile at them, acknowledge them through a nod, and so on.

This is particularly the case in many service industries:

grocery stores - associates and customers acknowledging each other (not during checkout, but just walking around in the store)

fellow gym members as well as staff and members (again only walking around, not during particular business related interactions)

Another example might be you walk in a public bathroom and someone just comes out the door, you'll look each other briefly in the eyes, "smile", nod, acknowledge each other, and move on.

Now here's the thing I've become aware of, and mostly guys do this:

We don't actually smile.

In fact, we are kind of grumpy looking. Our mouth and eyebrows go into a frown, we press our lips together, and the only thing close to a smile that we do is to create a crease on the sides of our mouth.

Hard to explain... And hard to find actual pictures of this...


besides that he looks in the distance and he looks concerned, but imagine he looks at you and gives you a nod like that. pretty close!


he looks slightly more surprised, and worried, then what people usually look like, especially because the eyebrows are going up.


he's got too much "darnit!" on his face, and his eyes are sad looking, but again, the general idea comes across.


he has an actual upward curved smile going on, but definietly the lips pressed together like that

So again:

  • Mostly guys do it
  • it is done for acknlowledgement/politeness when you cross paths
  • it usually goes with a nod and brief eye contact, whereas the nod goes down
  • the eyebrows might seem kind of like a frown, since you're noding down, while looking upwards in the persons eyes
  • your lips are pressed together
  • often the mouth will actually go into a reverse smile curve (meaning frown)
  • the mouth gets kinda pulled to the sides, like we're making a wide mouth, just like when smiling.

First of all: Do you know what I'm talking about? Do you do it? Has it been done to you?

Does it have a proper name?

Why do we do it? Why don't we actually smile? We do we look rather grumpy when smiling like that?

I've noticed that we do a similar face in many different situations. Sometimes someone might tell you something that might make you smile or even laugh, but to them it's rather sincere, so you press your lips together, trying to make a frown, but you still can't help to smile a little. There are many expressions that this kind of face can express (as you can see in the pictures), they all have a certain subtle difference to them, and definitely very different meanings, but I feel as if the mouth pressed together and kinda mixing a grin with a frown remains constant. The particular facial expression I am talking about is also accompanied by a nod, making it distinct.

Why do we do this so often?

Are we hiding something? Is this some sort of a default expression?

share|improve this question
This is interesting. I'm familiar with the distinction between authentic smiles (so-called Duchenne smiles) and inauthentic ones, in that the muscles around the eyes are only activated in the former kind. What you are talking about, though, seems more specific than that. I'm not sure I understand exactly what the phenomenon you're looking for is, but I think you might be over-generalizing a little. – lea Jul 14 '14 at 7:31
@olli: Yes, I do it also, and then I say to myself "where did I pick this up from" ?! I started doing it when I entered "adulthood" after college when working in the corporate world. I think I just picked it up from others around me. Maybe it reflects all the stress of the modern days professional man in a complicated contradictory world? – Greg McNulty Jul 14 '14 at 20:44
Understanding why people move their body in certain controlled and uncontrolled ways formally defined as micro expressions is a worthless endeavor. For one must understand the current state of the stimulus to the brain and the internal programming which dictates how and why a person responds in such a way. Modern psychology does not answer those questions. – user3832 Jul 16 '14 at 15:06
And I thought Dr. Lightman was on to something... – olli Jul 17 '14 at 18:14
up vote 3 down vote accepted

Since this (excellent) question has been around for a while without any answer, I thought I'd give my two cents, like the help centre suggests. Other people may be able to expand on this and find appropriate sources, research, etc.

I think we do this as a gesture of respect to the other person. We may fear that if we don't acknowledge them at all, it will come off as rude or arrogant. Maybe we fear that if we don't even look at the other person, we're basically pretending as if they're not there. So we want to acknowledge them in some way. However, they are often a total stranger, so we may feel that saying "hi" or anything like that, is a bit over the top. (Sometimes we may actually say "hi" combined with the frown, though.)

So, as you suggest in the question itself, it's a way to acknowledge the other person.

Now, why not give an authentic smile? Well, because it's a little bit difficult to give a real smile without actually being happy about something. If you see a dear friend for the first time in months, you'll probably give a real smile, because you are genuinely happy to see them. When you meet a total stranger, the truth is that that person doesn't really mean much to you. You might not really feel that you have anything to smile about.

Have you ever tried to smile on a picture, when you're actually not very happy? It's not easy. The smile often looks inauthentic. So we try our best to greet the passing person with respect, but it's not that easy to smile authentically.

Not wanting to look like a fake smiling clown, we may not even try that hard. The other person knows that we're just trying to acknowledge them. They're not looking to give us an Oscar award anyway. And we know that they know that.

If we were to make eye contact with them without altering our facial expression at all, we might end up looking a bit mad. (Imagine it, you cross paths with someone, and they just look into your eyes without altering their facial expression at all. Personally, I would be a bit freaked out if that happened.) Most changes in our expression will be better than nothing (except, of course for a downright hostile or angry face). It means we acknowledge that they are there, and we are making an effort to do so.

There's another possible reason: Fear of rejection. We want to acknowledge the person. So why not give them a real smile? Well, what if you do, and they respond with a careful nod, a frown like the ones in OP, or even totally ignore you? (This is quite possible, since it's not that easy to produce a genuine smile.) When you genuinely smile at someone, you are giving a little part of yourself out to them. If they then merely nod at you, or something like that, most people will feel uncomfortable. As if they just gave someone a gift and the other person was uninterested in the gift. I'm not saying this is a reasonable feeling, I'm just saying it's the way people might feel, thus motivating their behavior.

share|improve this answer
Nailed it! Sounds plausible to me. Maybe add a little bit of "I have nothing to smile about right now anyway" and I think thats it! – olli May 21 at 14:49
@olli I'm glad you liked it :) – Fiksdal May 21 at 15:01

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.