A 10-space coffee card pre-stamped twice will be completed faster than an 8 with no pre-stamps.
As humans and other animals approach reaching a goal, their efforts toward that goal increase (Locke & Latham, 1984). Rats run faster as they approach a food reward (Hull, 1934), and humans increase effort as they approach rewards such as gift certiﬁcates (Kivetz, Urminsky, & Zheng, 2006) or goals such as visual ﬁnish lines (Cheema & Bagchi, 2011).
Studies have shown that the goal gradient effect has a powerful effect on social motivation. For instance, a recent study has shown that people are more likely to pitch in as charitable campaigns approach their goals. This is because they feel a greater degree of perceived impact and a heightened level of satisfaction in donating at a later stage.
Sadly though, people are not charitable simply to be kind or to relieve negative emotions. Instead, they ﬁnd satisfaction from having personal inﬂuence in solving a social problem.