Their social rules for online interaction require a higher level of sensitivity than do those for in-person communication.
Teens work very hard to create a favourable online image by carefully selecting which photos, activities and links to post on Facebook and Instagram, a study has found.
Content that makes them appear interesting, well-liked and attractive to their friends and peers is a primary goal for adolescents when deciding what to share in digital spaces, researchers said.
"Teenagers arent just posting carelessly; theyre surprisingly thoughtful about what they choose to reveal on social media," said Joanna Yau, a PhD candidate at University of California, Irvine in the US.
"Peer approval is important during adolescence, especially in early adolescence, so theyre sharing content that they think others will find impressive," said Yau.
Facebook and Instagram provide opportunities for young people to connect and communicate with friends as well as people they know in person but are not necessarily close to, such as classmates.
These social media channels allow individuals time to craft and edit posts and, unlike offline situations, offer teens the chance to consider - even strategise about - how they want to present themselves online.
Researchers found that for girls, the effort to construct a favourable image can involve lengthy deliberation and advice from confidantes.
The process of posting pictures is particularly time-consuming and can be a joint endeavour among friends - ensuring that only the most flattering photos, filters and captions are selected.
Girls also actively enlist their friends to comment on and like their posts in an attempt to boost their popularity index, with especially savvy Instagram and Facebook users being active during peak social media traffic hours in order to maximise their number of likes.
Boys in the study did not ask pals for feedback or to like their posts.
"We found that some teens invested great effort into sharing content on Facebook and Instagram and that what may seem to be an enjoyable activity may actually feel tedious," Yau said.
"Their social rules for online interaction require a higher level of sensitivity than do those for in-person communication," she said.
"Even interesting and positive posts can be interpreted negatively. For example, sharing about college admissions could come across as pretentious and prideful," she added.
The study included 51 Southern California adolescents - 27 females and 24 males - between the ages of 12 and 18.
Ten focus groups - based on proximity, grade level and gender - consisting of three to eight youngsters were conducted.
At each grade level, there were female, male and mixed-gender groups, with no adults known to the participants present.