Facebook has an ingrained algorithm that keeps track of exactly how you interact with your friends and after that sorts appropriately. Resource
Facebook Friends List Order Meaning Timeline
While the specific ranking algorithm is secret, it does take into consideration the following factors:
* Exactly how typically you see your friends' accounts
* How usually you click on your friends' links
* Photos/tags alike
* Typical groups/ organizations
* utual Friends
* How commonly you search for friends
* Loved one appeal (exactly how prominent your friends are amongst your shared connections).
So, the real sorting is not arbitrary, however rather meticulously crafted to promote communication as well as website interactions.
