She said that the strongest predictor is how close one was at the peak of their friendship when the unfriending happened, and people may be more bothered and saddened if your best friend unfriends you.
The study has found four factors that predict someone's emotional response to being unfriended, which included being negatively affected if the unfriended person was once a close friend to the one who unfriended them and how closely the person monitored their own friend's list.
Another factor includes being less negatively affected if difficulties were discussed between the friends before the unfriending and if the person unfriended talked about it with others after the unfriending.
The research showed that unfriending happens more often to friends who were once close than to those who are acquaintances.
The researchers say, despite the preponderance of weak ties throughout online social networks, these findings help to place unfriending within the greater context of relationship dissolution.
The study was published in the 2014 47th Hawaii International Conference on System Sciences.