According to Motherboard, Facebook determines those nine friends based on 12 factors, including your interactions with those people on Facebook, profile views, tagged photos, wall posts, likes, comments, viewed photos, private messages, mutual interactions, friends who are currently online, friends you've added to the "friends" list, and friends you've added to the "friends" list. The site does not explain how it makes its determination for each user.
The site also notes that some options may not be available to users in certain countries. For example, users from France cannot see who has blocked them from their feed.
Finally, the site points out that people appear in your feed based on the actions they take, such as posting updates or tagging photos. If they stop posting content or remove themselves from your feed, then they will no longer appear there.
Facebook determines those nine friends based on several factors, including your interactions with those people on Facebook, profile views, tagged photos, wall posts, likes, comments, viewed photos, private messages, mutual interactions, friends who are currently online, friends you've added to the "close friends" group, and friends you've added to the "close friends" group. Changes to your privacy settings can also affect what information Facebook uses to determine which of your friends to show you.
For example, if you stop interacting with someone through email or Facebook, they will be removed from your list of friends. If you also don't visit their page, then there's no need for Facebook to connect with them any more. A similar thing happens when you delete your account; all of the content associated with your account is deleted, so Facebook cannot use that content to suggest other people to add as friends.
In addition, Facebook checks to make sure you're not using a fake email address to create accounts. Therefore, it's possible that even though you know someone personally, they won't appear on your friend list if their email address is fake or if you haven't communicated with them in some time.
Finally, Facebook looks at how many people you'd like to be your friends. If you ask too many people at once, you'll probably get told "you're already friends with most of these people," which explains why only nine friends show up on your profile.
Although Facebook's algorithms are unknown, there are several elements that influence them. It is the mechanism that determines which nine friends appear at the top of your profile page's list of friends. The order in which you list your friends is one factor used by Facebook to determine their ranking.
Other factors include the number of "likes" each friend page receives and how often you interact with these friends. For example, if a friend requests to be added to your list, this will increase the likelihood of them appearing at the top of your page.
As well as the ordering, other aspects of your profile that can affect your rank include your location, age range, gender, interests, and relationship status. For example, people in rural areas may be shown first because there are fewer opportunities for them to see her/him listed below. Likewise, someone who is not connected to the internet would not appear in your friend list at all.
Your age is another factor. People younger than you will usually be shown first as they are likely to be relevant to you based on your current life stage or situation. Those older than you also have an advantage as they will be seen by more people and therefore have greater chances of being shared with others.
These elements are as follows:
Here are a few variables that influence the algorithm that selects who appears at the top of your list:
Your relationship with each friend - new or old - will factor into the order in which they appear. For example, if you delete a friend, that person's name will no longer appear at the top of your list.
Similarly, the more activities you participate in together, the higher that friend will rank in the list.
If you comment on many of their updates, they will appear at the top of your feed.
Finally, the more friends you have, the better chance you have of appearing in someone's news feed. The goal is to make sure that every one of your friends sees some form of content from you.
In conclusion, the algorithm that decides what shows up in your news feed is complicated, but it does take into account various factors such as your relationship with each friend, the amount of activity between you and they, and most important, how many other friends you have.
Professor Robin Dunbar investigated the link between Facebook friends and actual friends and discovered that only 14 of the average 150 Facebook friends a person has would exhibit sympathy for the user in real life; just five Facebook friends could be termed "close friends." His research also revealed that people tend to have more close friends than casual friends.
People have different numbers of friends on Facebook because people have different levels of involvement with the site. Someone who is very involved will add many friends, while someone who is not at all involved will only have a few friends. There are two types of friends on Facebook: explicit and implicit. Explicit friends are people you know personally such as family members or friends from work or school. They can be added directly from your contact list or through a search option on the site. Implicit friends are people who have liked some of your photos or joined some of your groups. These friends cannot be added directly but appear on your news feed each time you log in to the site.
According to Professor Dunbar, there is a maximum number of friends that any human being can have without becoming unpleasantly crowded. He estimated this number to be around 200, by comparing the online friendship network with social networks found in other species.