Tag Archives: smile

Children smiling.

AI can now tell if you’re a man or a woman, just by your smile

Men and women have different patterns of smiling, new research reports — and this, the authors add, can allow AI to easily distinguish between the genders.

Children smiling.

Image credits Benjamin D. Glass / U.S. Navy.

Many a man has been enraptured by the right smile, and many more will probably follow — although the opposite doesn’t seem to hold true. Regardless, while romance unfolds across the world, one team of researchers from the University of Bradford is working to bring this subtle yet powerful gesture to bear in our interactions with artificial intelligence (AI). According to them, computers can learn to differentiate between men or women simply by observing a smile.

Led by Professor Hassan Ugail, the team mapped 49 distinct points (or ‘landmarks) on smiling human faces — mainly around the eyes, mouth, and down the nose. These points were then used to measure how underlying muscle movements changed the participants’ faces while smiling. These recorded changes included both the distance between different points and the ‘flow’ of the smile, i.e. how much, how far, and how fast the different landmarks moved as a person was smiling.

Birds of a gender smile together

Then, the team crunched the data to determine if ladies smile differently than gents — and they did. The team notes that there are ‘noticeable differences’ in smile-patterns between the genders, with women able to boast having the more expensive ones.

“Anecdotally, women are thought to be more expressive in how they smile,” says Ugail. “Our research has borne this out.”

“Women definitely have broader smiles, expanding their mouth and lip area far more than men.”

Based on their findings, the team created an algorithm to analyze smile patterns and tested it against video footage of 109 people as they smiled. They report that the algorithm correctly determined the gender of the smile-es in 86% of the cases — and they believe that this accuracy can be easily improved. Ugali claims the algorithms relied on “fairly simple machine classification” as they were just testing the validity of the concept; a more sophisticated AI could easily improve the recognition rates, he adds.

Automatic gender recognition is already available and in use today. But existing methods draw on static images, and compare fixed facial features. This is the first software to use dynamic movement to distinguish between men and women, and the team hopes that their work will help enhance machine learning capabilities in the long run.

However, their research has also raised some intriguing questions that they’re planning on pursuing — for example, how would their software respond to the smile of a transgender person, and how would plastic surgery impact the smiling patterns of a subject?

“Because this system measures the underlying muscle movement of the face during a smile, we believe these dynamics will remain the same even if external physical features change, following surgery for example,” said Professor Ugail.

“This kind of facial recognition could become a next-generation biometric, as it’s not dependent on one feature, but on a dynamic that’s unique to an individual and would be very difficult to mimic or alter.”

The paper “Is gender encoded in the smile? A computational framework for the analysis of the smile driven dynamic face for gender recognition” has been published in the journal The Visual Computer.


Smiles can both induce and reduce stress — it depends on how you wield it

New research finds that smiles can be used to both soothe or attack — at least, as far as the brain’s stress pathways are concerned.


Image via Pixabay.

A faltering voice. A racing heart. Sweaty palms. Those are some of the symptoms of stress that we’ve all experienced at one time or another — during an exam, before an exciting date, before speaking in public. We know that such events can instill stress even in the most level-headed out there, but new research shows that a single smile can also have the same effect — if done well.

The study, published by researchers from the University of Wisconsin-Madison and Bar-Ilan University, looked at the interaction between nonverbal feedback and the activity of the hypothalamic-pituitary-adrenal (HPA) axis, our body’s central stress response system.

We know that verbal feedback, such as telling someone “that was/wasn’t good” following a speech can influence the activity of the HPA axis, either determining a rise or a lowering of stress-hormone cortisol. However, there was very little scientific research looking into how our HPA axis responds to purely nonverbal feedback, such as facial expressions.

Turns out your brain is actually paying a lot of attention to all of these cues. The team reports that smiles can reduce or increase physical stress, depending on how they are perceived. They also showed that smiles with different social functions have different effects on the HPA axis, when perceived as feedback in the context stressful social situations.

For the study, the team worked with 90 male undergrad students, using the cortisol levels in their saliva as a measure of their HPA activity. They report that ‘dominance’ smiles, those smirky things we use to convey disapproval or to challenge social standings, were associated with higher HPA axis activity — this type of smile correlated to an increase in heart rates and levels of cortisol in the participants’ saliva. Those who perceived ‘dominance’ smiles also needed a longer period to return to their baseline cortisol levels after experiencing a stressful event. All in all, the team notes, the physical responses to dominance smiles mirror the effect of negative verbal feedback on the HPA axis.

On the other hand, ‘reward’ and ‘affiliation’ smiles — which reinforce behavior, grease social wheels, or are meant to signal the lack of threats — have an effect similar to displays of friendliness or positive verbal feedback on the HPA axis, lowering the participants’ stress and improving their psychological resilience to stress.

Types of smiles.

Reward smiles (left) reinforce desired behavior by signaling positive feelings; affiliation smiles (center) promote approachability by signaling non-threat; dominance smiles (right) influence social hierarchies by signaling superiority.
Image credits Jared D. Martin, Magdalena Rychlowska.

The authors further report that individuals with higher heart-rate variability (the variation in time between heartbeats) showed the widest range of responses to different smiles. Higher heart rate variability has previously been correlated with a higher ability to recognize facial expressions.

“The findings provide further evidence for the view that smiles do not necessarily constitute positive nonverbal feedback, and that they may impact social interactions by affecting the physiological reaction of people who perceive them,” the authors write.

“In addition, cortisol appears to support the detection of social threat and coordinate biological activity needed to adequately respond to the threat.”

The findings help patch in our understanding of the depth of nonverbal communication in human language — as a tool to unnerve, a hand to soothe, and as an outside effect on our psychological state. However, the team cautions that because of the small sample of exclusively male participants, the findings shouldn’t be generalized until replicated. Thus, further research will need to explore whether or not men and women react differently to the same kind of smile, and to test more overt (both negative and positive) facial expressions.

The paper ” Functionally distinct smiles elicit different physiological responses in an evaluative context” has been published in the journal Scientific Reports.

According to scientists, these are the three kinds of smile

People smile in a number of ways and in a wide range of contexts, but according to a new study, all of them fall into one of three categories: rewardaffiliation, and dominance.

A smile can change the world

A smile is a strange thing. We do it by using our facial muscles, but more often than not, it’s more than just the mouth that smiles. A smile which doesn’t involve contracting the corners of the eyes, for instance, always looks a bit weird. It’s also not a completely involuntary reaction (like a grimace) — cross cultural studies have found significant differences in the way different cultures smile; obviously, we can also fake a smile. But no matter how people smile around the world, smiling is one of the most important social cues, and people have been doing it since forever. Actually, smiling predates the existence of modern people by quite a lot.

Primatologist Signe Preuschoft traces the smile back over 30 million years of evolution to a “fear grin” stemming from monkeys and apes. Across history, smiling evolved differently in different species, and in humans, in different cultures.

Also contrary to popular belief, smiling isn’t really a precursor for laughing — although we use it a lot when we’re amused. More than anything, smiling is used to convey social information. Sexual advertisement is one of its main functions. Every flirt starts with a smile, and smiling to someone is one of the simplest and more effective ways of telling someone you find them appealing. But a smile can do much more than that. It can show reinforcement, it can be used for manipulation, or even to mask confusion. Different people smile in a lot of different ways, but according to researchers from the University of Wisconsin-Madison, they all fall in one of three categories.

Smike like you mean it

“When distinguishing among smiles, both scientists and laypeople have tended to focus on true and false smiles,” said Paula Niedenthal, a psychology professor at the University of Wisconsin-Madison.

The classical belief, she adds, is that a person smiles but isn’t happy, the smile isn’t sincere. But smiling is associated with so many emotional states, that belief is simply not true. In fact, it’s more than not true, it’s counterproductive. Believing that smiles are intrinsically linked to happiness skews our understanding of the process, and scientists want to change that idea.

  • The first type of smile, they say, is the reward smile. This is the most intuitive one, “the kind of smile you would use with a baby, so he will smile back or do things you like”, says Niedenthal. It’s basically a way of saying you’re feeling good about something. It’s the “I like you” smile. The study describes them thusly:

Reward smiles are displayed to reward the self or other people and to communicate positive experiences or intentions… the reward smile may have evolved from the play face of primates and canids.

  • The second type is the affiliative smile, which above anything, communicates tolerance. It’s the “I don’t necessarily like you, but you’re OK” smile. It’s used to ease in social bonding.

Affiliative smiles facilitate social bonding by communicating approachability, acknowledgment, and appeasement and thus may be functionally similar to the silent baredteeth display in chimpanzees that occurs during grooming, sexual solicitation, and submission.

  • The third type has a darker side. The dominance smile is used to signify social status, but it also involves facial movement that is associated with joyfulness, which makes it a bit confusing.

Dominance smiles serve to maintain and negotiate social or moral status and are associated with superiority or pride, defiance, derision, and contempt. Unlike reward and affiliative smiles, dominance smiles are assumed to elicit negative feelings in observers. No homologous primate facial expression is known; however, some facial expressions displayed by high-status animal aggressors involve smile components.

Smile, humanz

Rather ironically, in order to understand how humans smile, researchers analyzed thousands of computer-generated expressions, involving different (random) combinations of facial muscles. They asked volunteers to say whether each was a reward or affiliative or a dominance smile, or not a smile at all. After this, researchers looked at the algorithm that generated each smile and identified the ‘recipe’ for each type of smile.

“We now know which movements we should look for when we describe smiles from real life,” said Magdalena Rychlowska from Cardiff University, who was the lead author of the study. “We can treat smiles as a set of mathematical parameters, create models of people using different types of smiles, and use them in new studies.”

It’s not the first time a trichotomy of smiles has been proposed. Some of the current authors proposed it back in 2010, but this latest work does a lot to solidify that theory. Rychlowska et al. also published a paper in 2015 discussing the “main reasons for smiling” — but that study, just like this one, had a major limitation: participants were all white, American college students, and the virtual faces were also white. But taking this into consideration, the study concludes that “results highlight the versatile nature of the human smile, which can be used for multiple social tasks, including love, sympathy, and war.”

Two boys smiling in Bangladesh. Image credits: Sumon Mallick.

Aside from better understanding our social cues, this study can also have a more pragmatic result: it can help plastic and reconstructive surgeons better repair and reconstruct people’s face bones and muscles, making them seem more realistic.

Journal Reference: Magdalena Rychlowska et al Functional Smiles: Tools for Love, Sympathy, and War. DOI: https://doi.org/10.1177/0956797617706082

Smiling facilitates stress recovery

Just grin and bear it – we’ve all heard it at one point or another in our lives, and we’ve probably hated hearing it. But could there be some real scientific fact behind this piece of advice? Can smiling actually help you feel better?

Smile psychology

In a study forthcoming in Psychological Science, a journal of the Association for Psychological Science, researchers Tara Kraft and Sarah Pressman of the University of Kansas take a look at the benefits of smiling by analyzing different types of smiles, as well as the impact of smiling awareness and how it affects individuals’ ability to recover from episodes of stress.

“Age old adages, such as ‘grin and bear it’ have suggested smiling to be not only an important nonverbal indicator of happiness but also wishfully promotes smiling as a panacea for life’s stressful events,” says Kraft. “We wanted to examine whether these adages had scientific merit; whether smiling could have real health-relevant benefits.”

Smiles are typically divided into two categories: standard smiles and genuine (or Duchenne) smiles. The difference is that in standard smiles, the muscles around the mouth contract, while in genuine smiles, both the muscles around the mouth and the eyes contract. Previous research shows that positive emotions can help during times of stress and that smiling can affect emotion; however, the work of Kraft and Pressman is the first of this kind, which experimentally manipulate the types of smiles people make in order to examine the effects of smiling on stress.

Smile like you mean it

The researchers recruited 169 participants from a university, and the study consisted of two phases: training and testing. During the training phase, the participants were divided into three groups, and each group was asked to display a different facial expression. Interestingly, participants were asked to hold chopsticks in their mouths in such a way that they engaged facial muscles used to create a neutral facial expression, a standard smile, or a Duchenne smile. The chopsticks were essential for the task because they forced people to smile without them being aware that they were doing so: only half of the group members were actually instructed to smile.

For the testing phase, participants were asked to multitask; what they didn’t know was that the multitasking activities were designed to be stressful. During all stressful tasks, participants held the chopsticks in their mouth just as they were taught in training. The researchers tested heart rates and self reported stress levels throughout this phase.

The results of the study seem to indicate that there is a clear connection between smiling and our physical state. Compared to participants who held neutral facial expressions, smiling subjects (especially those with Duchenne smiles) had lower heart rate activities after recovery from stressful activities. But whats even more interesting, participants who held chopsticks in a manner that forced them to smile, but were not explicitly told to smile as part of the training also reported a smaller decrease in positive affect compared to those who held neutral facial expressions.

“The next time you are stuck in traffic or are experiencing some other type of stress,” says Pressman, “you might try to hold your face in a smile for a moment. Not only will it help you ‘grin and bear it’ psychologically, but it might actually help your heart health as well!”


Gloomy men are more sexually attractive than happy looking fellas

I a recent study published by the University of British Columbia, Canada, it seems women are more sexually attracted by men who display a more gloomy complexion or awareness of social norms by displaying shame, than men who look happy all the time.

The study published online Tuesday in the American Psychological Association journal Emotion showed pictures of the opposite sex to both men and women. About 1000 participants were then asked to rate the sexual attractiveness of hundreds of photos of the opposite sex, based on the expressions they saw.

“Men who smile were considered fairly unattractive by women,” said Jessica Tracy, a University of British Columbia psychology professor who directed the study.

“So to the extent that men think that smiling is a good thing to do if they want to be found sexually attractive our findings suggest that’s not the case,” Tracy said.

The men’s reaction was just the opposite.

“Women who smile are absolutely very attractive. That was by far the most attractive expression women showed,” Tracy said in an interview.

Thus, researchers could conclude that women were least attracted to smiling, happy men, preferring those who looked proud and powerful or moody and ashamed. The study is only based on first impression alone, and correspondents were asked to fill their perceptions according to sexual desires, and not from a relationship stand point.

Past research has shown that  smiling is associated with a lack of dominance, which is consistent with traditional gender norms of the “submissive and vulnerable” woman, but inconsistent with “strong, silent” man, the researchers say. “Previous research has also suggested that happiness is a particularly feminine-appearing expression,” Alec Beall, a UBC psychology graduate student and study co-author adds.

“Generally, the results appear to reflect some very traditional gender norms and cultural values that have emerged, developed and been reinforced through history, at least in Western cultures,” Tracy says. “These include norms and values that many would consider old-fashioned and perhaps hoped that we’ve moved beyond.

Displays of shame, Tracy says, have been associated with an awareness of social norms and appeasement behaviors, which elicits trust in others. This may explain shame’s surprising attractiveness to both genders, she says, given that both men and women prefer a partner they can trust.

Although, a big smile always helps socially and asserts friendliness, it doesn’t seem to help men socializing in a bar get laid. Nobody likes a guy who smiles too much, it seems. The study also adds fuel to the notion that women are attracted to bad boys.

“Women are attracted to guys like James Dean, Edward the vampire. The guys who are flawed, but who know it and are tortured by it,” Tracy said

She emphasises, however, that the study explored first impression, and the team are not recommending men adopt a no-smile policy for a long-term relationship. “We’re not saying don’t be a nice guy,” she says.

Women of ZME Science, how far is this study from the truth in your perception? Be honest.