1. memory = shared emotional memories - a bond is likely to be formed if these are meaningful events
(eg births, deaths, trauma, joy, birthdays)
2. biography = 'life history' or shared experiences - stronger relationships are formed with those who have the same experiences as you (particularly true for adolescents who strive for independence from blood relations)
(eg travelling together, going to same school/ uni, working at same place)
3. embeddedness = 'interconnected web' or your social circle - who you spend most time with determines how strong your relationship is
(eg more time spent with friends > siblings who are away at uni and vice versa)