With the widespread emergence of required community-service programs comes
a new opportunity to examine the effects of requirements on future behavior
al intentions. To investigate the consequences of such "mandatory volunteer
ism" programs, we followed students who were required to volunteer in order
to graduate from college. Results demonstrated that stronger perceptions o
f external control eliminated an otherwise positive relation between prior
volunteer experience and future intentions to volunteer A second study expe
rimentally compared mandates and choices to serve and included a premeasure
d assessment of whether students felt external control was necessary to get
them to volunteer: After being required or choosing to serve, students rep
orted their future intentions. Students who initially felt it unlikely that
they would freely volunteer had significantly lower intentions after being
required to serve than after being given a choice. Those who initially fel
t more likely to freely volunteer were relatively unaffected by a mandate t
o serve as compared with a choice. Theoretical and practical implications f
or understanding the effects of requirements and constraints on intentions
and behavior are discussed.