Do women really show their emotions more than men?

It's a stereotype that has improved a little over the years but still persists: women are more emotionally expressive than men. Like Bridget Jones, we constantly reveal exactly how we're feeling, while men, Mark Darcy-like, look on impassively.

Although prior evidence suggests that women really do smile more often, a new study, published in PLOS One, has considered a greater variety of facial expressions, and it finds that the gender pattern is more complex, with some emotions displayed more by men than women. Arguably, this work helps to reveal not only differences in the emotional signals men and women send to others, but also differences in the emotions that we feel.

Daniel McDuff of Microsoft Research, Redmond, US and his team used a new automated facial coding technology to analyse the expressions of 2,106 people as they watched a series of 10 video adverts at home.

The participants were crowdsourced from France, Germany, China, the US and the UK. While they watched ads from their own countries on everything from confectionary to cars, their webcams streamed images of their faces to a remote server.

The women smiled more than the men, replicating the earlier research. They also engaged in more "inner brow raises", an expression taken to indicate fear or sadness. But the men frowned more. Frowns are usually taken to be a show of anger, though the researchers noted that in this study, they might have reflected greater concentration, or confusion. There were no gender differences in some other expressions, including downturned mouths.

There is an ongoing debate in psychology about the extent to which facial expressions, including smiles and frowns, actually reflect and match felt emotions. When you smile, is it always because you're feeling happy? Or do you sometimes smile when you're anxious? And just because you're frowning, does it necessarily mean you're mad – or you just want someone else to think you are?

But given work suggesting there is a close association between emotions and facial expressions, an implication of the new results is that women are more prone to feeling happy and also more anxious (or at least more inclined to show these emotions), and that men are more likely to feel angry (or more confused…), which raises the question of why might this be?

McDuff and his team suggested that at least part of the explanation could be down to the different social expectations and pressures placed on the genders. For example, there's evidence that in many countries, happiness is seen as more desirable for girls than boys.

Such an account would help explain why the size of the observed gender differences varied around the world, being the smallest in the UK, consistent with the idea that gender-related social expectations are less marked in some countries than others.

There were a few other geographical differences: women in the US were the smiliest, while women in the UK and Germany frowned least. But the general data patterns in each of the five countries were the same.

One limitation with the study was the fact that volunteers knew they were being videoed, which might have influenced their reactions. But a major advantage was the use of rapid automated coding technology. This allowed for many more participants than would normally be practical in research on facial expressions, which are usually decoded by a researcher. Crowdsourcing volunteers and using computer-based decoding, as in this case, could open the way for many more mass-studies of emotion and behaviour.