"Over the course of 7 years, we replace 48% of our friends with new ones … The total never changes: there's only so much room for new people in your life", Gerald Mollenhorst, 2009
The survey contained questions such as: Who do you talk with, regarding personal issues? Who helps you with DIY in your home? Who do you pop by to see? Where did you get to know that person? And where do you meet that person now?
You may have more Facebook friends as the years go by, but when it comes to your close friends, you lose about half and replace them with new ones after 7 years. Managing relations on a large scale is impossible. Mollenhorst also established that networks were not formed based on personal choices alone. Our friend choices are limited by the opportunities to meet.