When you post to Facebook, do you share a bikini selfie or one of you all pumped up from the gym? As studies are increasingly showing, who you project yourself to be on social media matters — especially to teens.

Platforms such as Facebook, Twitter, Instagram and Snapchat clearly don’t have to cause people to freak out about how other people perceive them and then rush to the plastic surgeon. But in some social media circles, as with certain cliques in high school, postings can actually cause others to place more of an emphasis on their self-image.

You’re probably familiar with the idea of objectification, which is when someone views someone else as more of an object (usually a sexual object) than a person with thoughts and feelings. Social media provides an easy way for people to portray themselves — yes, themselves — in an objectified manner. It’s called self-objectification.

Perhaps they only post selfies with their tummy sucked in, or when their makeup is just so, or when their clothes look good, or when they stand next to a clean and shiny car. You get the (perfect) picture.

Well, there’s reason to believe those images of unattainable perfection could actually affect the people who see them.

In one online experiment, Dutch researchers Dian de Vries and Jochen Peter had 221 women between ages 18 and 25 participate in what the women thought was a consumer survey. They were shown fragrance advertisements that depicted either a perfume bottle (non-objectified ad) or a sexy woman in lingerie (objectified ad).

Then the women had to create an online profile and write a description of themselves. Some were told it would be seen by an online audience, while others were told it wouldn’t.

Those who were primed with “sexually objectifying stimuli,” as the study put it, and who believed their profile would be public, were more likely to get caught up in the “glory” rat race. In their self-descriptions, they were more likely to say they were interested in fashion or cosmetics, or describe their physical characteristics in positive ways. Essentially, they were more likely to self-objectify.

The study shows how images in the media — and the power of public attention — may alter the way people perceive themselves, causing them to place more value on physical qualities and less on the human element.

In an unofficial survey, the American Academy of Facial Plastic and Reconstructive Surgery released information about a change noticed by its plastic surgeons. A third of those surveyed saw an increase in 2013 over the previous year in requests for plastic surgery stemming from people being more self-aware of their looks because of social media.

Can a proliferation of selfies online really propel people toward Botox and rhinoplasty?

We don’t really know. Only 69 doctors answered the question in a Survey Monkey poll, so the review wasn’t scientific by any means — though it proved good fodder for debate in blogs.

But the idea that social media can change the way people think and act is a powerful one. Facebook and Twitter have aided revolutions. They can certainly affect how people, particularly teens, feel about themselves — for good or bad.

As one recent study found, emotions online can be kind of contagious. After examining a billion updates from a million or so Facebook users, researchers found that when people post something sad or grumbly, it can cause others to post downbeat messages, too. Though the effects were relatively small, the same happened with upbeat messages: Positive posts generated more positive posts.

So the next time you’re itching to share something about your day, think twice about posting your lingerie or Speedo selfie and making the rest of us feel bad about ourselves. Or, perhaps the rest of us should just get over it and use our knowledge about the emotional ripple effect of social media to prevent ourselves from getting swept up in the unrealistic expectations glaring out from our Facebook news feed.