It's all in a smile. Or is it a frown?

Every morning, I take the underground to work. Sometimes I read. Sometimes I listen to my MP3 player. But this morning I sat and observed.

I was curious about people's facial expressions. A few days ago, I read that our abiliity to read facial expressions depends on what culture we belong to. How can that be? Well, apparently different cultures concentrate on different parts of the face. This morning, I was testing where I looked.

So on my trip to Spot on today, I looked at lots of people. I worked out that the person sitting opposite wasn't too pleased about going to work this morning. The same could be said about the woman who got on halfway through my journey. And the man I passed on the platform looked upset. Maybe his girlfriend had dumped him, or someone had stamped on his foot!

When I was finished with my test, I thought about where I had looked. I realised I had paid particular attention to the eyes and the shape of the mouth. Is the mouth curled up, or down? Are the eyes wide open, or scrunched up or frowning. We all use this information to decide whether someone is happy, sad, angry, or scared.

Or so we think! In other parts of the world, it appears to be different. According to the article I'd read, researchers in Glasgow have found that Asian people tend to concentrate ONLY on the eyes when working out how someone is feeling. This can make it difficult to tell the difference between surprise and fear, or disgust or anger. Try it out with a friend. Pretend to be disgusted and then pretend to be angry - but cover up your mouth so your friend can't see it! Did they guess correctly? Not seeing an angry flash of the teeth or a disgusted curl of the lips can make it really tricky!

So mouths play a big role in showing people how we feel. But they also play a role when telling someone to stop staring at them! I did find a happy-looking person in the train this morning. But her smile turned to straight lips and angry eyes (or was it disgusted?) when she realized I was watching her. Luckily it was my stop and I managed to escape before she could tell me off. And I'm sure everyone would have understood that.