The idiom “Don’t judge a book by its cover”  means you shouldn’t form an opinion about someone based on appearance or personality. Yet the reality is, much of society – from school to the business world – does just that. That’s where a simple smile can make a major difference.

This tendency can be particularly rough on a young person’s psyche – and future development – when classmates tease them about their looks. One of the top reasons students give for being bullied is physical appearance, according to the National Center for Educational Statistics. Studies show victims of this type of ridicule are often withdrawn and lack self-confidence, which can affect them well into adulthood.

“Children can be cruel to each other about appearance, and being the target of mockery or bullying leaves a real mark on on a child’s psyche,” says Dr. Kerry White Brown, an orthodontist and author of A Lifetime of Sensational Smiles: Transforming Lives through Orthodontics. “The pressure only gets worse as they get older; they’re less likely to participate, and that holds them back from realizing their true potential, both in school and out.”

Conversely, making improvements can enhance the story of one’s life. For example, losing weight or making cosmetic changes like straightening teeth often alters how we’re perceived and feel about ourselves. A Penn State University study found that people who smile more tend to be seen as more likeable and more competent, and an article in The Washington Post cited statistics that attractive smiles lead to higher-paying jobs and greater satisfaction in life.

“When you look at the research, a child that has a confident and consistent smile makes them a healthier person overall,” White Brown says. “They’re seen in a more positive light, versus someone who never smiles, and this can carry into their future prospects.”

White Brown gives three ways a smile makes your child healthier, which can lead to a happier adult:

  • Lowers stress and anxiety. Smiling releases endorphins, the chemicals in your body that make you feel happier. “Kids with crooked teeth hide their smile or never smile, and often they’re bottling up stress,” White Brown says. “They become introverts. Being confident to smile relaxes them and gives them a new lease on life.”
  • Strengthens the immune system. “The physical effects can’t be understated, and are all the more reason parents should make sure they have happy children who aren’t overly self-conscious or down about their appearance,” White Brown says. “It’s been proven that smiling helps your body produce white blood cells to help fight illnesses.” Hungarian health research teams studying smiles published evidence that sick children who were made to smile significantly increased their white blood cell count.
  • Makes you more self-confident. “It starts with the fact that when you smile, others are more likely to smile back at you,” White Brown says. “It makes you more approachable, more likely to engage with others and grow in the process. That’s one reason some business people think a winning smile is as important to leadership as management technique.”

“How you feel about yourself isn’t just important when you’re a child,” White Brown says. “How you saw yourself then and how you see yourself as an adult can be linked, and it can impact your choices and options throughout your life.”