This smile is the gold standard of all smiles.The <a href="https://www.healthline.com/health/duchenne-smile">Duchenne smile </a> AKA genuine smile make you seem <a href="https://ambadylab.stanford.edu/pubs/2010-Ozono%20et%20al.pdf">trustworthy </a>, authentic, and friendly.Mechanism :It’s the one that involves the mouth, the cheeks, and the eyes simultaneously. It’s the one where your whole face seems to light up suddenly.

10. Duchenne smile

Most of the smiles comes from a positive reaction — contentment, approval, a "well done" from your peers.<a href="https://doi.org/10.1177/0956797617706082">Researchers </a>describe these as “reward” smiles because we use them to motivate ourselves or other people.

1. Reward smiles

People <a href="https://www.healthline.com/health/successful-smiles-and-when-to-use-them">smile</a> to reassure others, to be polite, and to communicate trustworthiness, belonging, and good intentions.Smiles like these have been termed as “affiliation” smiles since they function as social connectors.A gentle smile is often perceived as a sign of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6343863/">compassion </a>Mechanism:These smiles involve the upward pull of the lips, and according to researchers, often trigger <a href="https://www.healthline.com/health/cheek-dimples">dimpling in the cheeks </a>.

2. Affiliative smiles

The list of social situations requiring a pleasant expression is long, one of them is when you greet a person.Lots of social situations calls for trustworthy friendliness but not emotional intimacy .Mechanism: Most of the time, a polite smile involves the zygomaticus major muscle, but not the orbicularis oculi muscle. In other words, your mouth smiles, but your eyes don’t.

6. Polite smile

This might sometimes be difficult to show or understand.One <a href="https://www.tandfonline.com/doi/abs/10.1080/02699931.2013.817383">study </a>found that attractiveness is heavily influenced by intense smile that can “compensate for relative unattractiveness.”Tips: Some tips are subtle: Keep your lips together and lift an eyebrow . Some are coy: Smile while tipping your head down slightly . Some are downright comical: Smile with a little whipped cream or coffee froth on your lips.

7. Flirtatious smile

People can use smile to show their superiority, to communicate discontent, and to make others feel inferior. One can call it a sneer.Mechanism: A dominance smile is more likely to be asymmetrical - One side of the mouth rises, and the other side remains in place or pulls downward.It may also include a lip curl and raising of an eyebrow t, both of which are definite signals of disgust and aggresion.Studies show dominance smile works.

3. Dominance smiles

This smile gets its name from the Pan Am flight attendants who were required to keep smiling, even when customers and circumstances made them want to throw peanut packets across the cabin.It can be seen as forced and fake.Mechanism: they use extra effort to yank on their zygomaticus major muscle.As a result, the corners of the mouth are extra high, and more of the teeth are exposed.

9. Pan Am smile

If you’re trying to find a reliable lie detector, the face isn’t !According to <a href="https://journals.sagepub.com/doi/abs/10.1207/s15327957pspr1003_2">research </a>, even the most experienced law enforcement officials only spot <a href="https://www.healthline.com/symptom/lying">liars </a>about half the time.Such smile patterns are commonly seen among people who were actively trying to deceive others in high-stakes situations.Mechanism: The zygomaticus major muscle — the one that pulls your lips into a smile — becomes very active

4. Lying smile

This can be seen in situations of commiting blunders in front of group of people. However, smiling can actually alleviate some awkward scenarios.Mechanism: A study found that a smile provoked by embarrassment is often accompanied by a downward tilt of the head and a shifting of the gaze to the left.If you’re embarrassed, you’ll probably touch your face more often, too.

8. Embarrassed smile 

Nothing transcends the language barrier like a smile

The sheer dexterity of human emotion is astonishing. So, we’re able to smile in the midst of both emotional and physical pain.It acts as a coping mechanism to smile and laugh during the grieving process (emotional/physical pain)<a href="https://www.hindawi.com/journals/prt/2013/128093/">Researchers </a>monitored the facial expressions of people who were undergoing painful procedures and found that they smiled more when loved ones were present than when they were alone as a sign of reassurance.

5. Wistful smile

Researchers have identified 10 main types of smiles. Here’s an explanation of these smiles, what they mean, and how they may affect the people you encounter.