I’ve been reading a fantastic book by Nir Eyal called “Hooked – How to Build Habit Forming Products.” In it Nir explores the brain’s trigger + reward response to being stimulated by software, games and social networks.

Uhg! What’s that Nir? I’m an addict? Checking Email seems to be my primary vice… then Facebook, then Tumblr. But it is good to know I’m not alone. Apparently, about 1/7th of the world’s population is also addicted to Facebook these days. Wow! And why?

According to Facebook’s Newsroom Facebook now has 936 million daily active users on average for March 2015. And it turns out, there is scientific research that explains this widespread use of Facebook. Liking and commenting on posts, sharing links, posting status updates; these simple actions provide a psychological satisfaction for users, and here’s why:

Liking: According to the Pew Research Center, 44% of Facebook users “like’ posts at least once on a daily basis. One of the reasons of the reasons for this is that it helps us make contributions to a conversation. A “like” is the online version of a nod, a “yes”, or an “I agree”, which makes the reader feel good for contributing their opinion. Another reason is that a “like” is a wordless statement about ourselves. The content we choose to “like” can actually predict our race, gender, political party, and other traits, so what we “like” says a lot about ourselves. Lastly, “liking” a post lets us express virtual empathy. Studies have shown that those who are more empathetic online are also empathetic in real life, and “liking” a post is a way to show this empathy.

Commenting: People choose to comment on a post when they have something to say. This is actually more satisfying for users than “liking” because it makes people feel less lonely, and it feels more personal than a single “like.”

Updating Your Status: posting a status update makes users feel more connected and less lonely, but only about 10% of users update their status daily. The reason for this is that when someone receives little to no comments or “likes” on their status, they feel more lonely and left out, which discourages users to post anything in the first place.

Sharing Content: Users tend to share engaging, funny, or interesting content that appeals to strong emotions on Facebook. A study done by the New York Timesshows some of the major reasons that people choose to share content: 49% of users shared content that they thought would entertain their friends, 68% shared content that would explain their personalities or things they like, 78% shared content to help build or strengthen relationships, 69% shared information that helped them feel connected to the world, and 84% shared information on issues or causes that were important to them.