為什麼我們總是沒辦法脫離那些人生中我們覺得很難搞的人？要成為至交好友需要多少時間？能夠量化嗎？這一集我們討論關於友誼的社會學。

本集的參考資料：
Studies show friendships lasting more than 7 years will last a lifetime（標題的說法原文研究沒提到）
Granovetter, M. (1974). Getting a Job: A Study of Contacts and Careers. Harvard University Press.
Social capital I: measurement and associations with economic mobility [Link]
Social capital II: determinants of economic connectedness [Link]
https://d.lib.msu.edu/etd/48309?q=Life
How many hours does it take to make a friend? [Link]
Social contexts and personal relationships: The effect of meeting opportunities on similarity for relationships of different strength