1. Aknin and Human (2015)發現如果禮物可以反映interests and passions of the giver，可以加強大家的bonding effects，所以唔一定要送人地鍾意既禮物先開心，比對方知道你鍾意咩可以加深彼此的了解(opens up and makes himself vulnerable)，例如送一場你喜歡的音樂會門票。
2. 貴價禮物證明the willingness to invest in a relationship，即係誠意，strong signal of the perceived depth of the relationship，所以愈熟的人送禮反而會ignore the explicit preferences of the recipients on the wish lists，而將禮物視作一個relationship signal，反而唔熟的朋友會傾向送你想要既野，因為佢地do not feel the motivational conflict and select something from the wish lists。
