The team found that having more than 300 Facebook friends increased teenagers’ levels of cortisol while those who only posted “likes” on their Facebook friends to encourage them actually decreased their cortisol levels.
“We were able to show that beyond 300 Facebook friends, adolescents showed higher cortisol levels. We can imagine that those who have 1,000 or 2,000 friends on Facebook may be subjected to even greater stress,” explained Professor Sonia Lupien from University of Montreal.
“While other important external factors are also responsible, we estimated that the isolated effect of Facebook on cortisol was around eight percent,” Lupien noted.
Lupien and her colleagues recruited 88 participants aged 12-17 years who were asked about their Facebook use, number of friends, self-promoting behaviour, and the supporting behaviour they displayed toward their friends.
Along with these four measures, the team collected cortisol samples of the participating adolescents.