This study examined the effects of own need and partner need for a resource
on cooperative behavior in a social dilemma. Based on Deutsch's (1975) nee
d principle, it was hypothesized that (a) participants in cohesive groups w
ould make smaller withdrawals when their partners had high need for the res
ource than when their partners had low need for the resource; and (b) parti
cipants with high own need would make similar withdrawals as those in the l
ow own need condition. Own need for a resource was manipulated by creating
either high thirst (participants ate spicy chips with salsa) or low thirst
(participants drank Gatorade). Partner need was manipulated by telling part
icipants that their partner had either high thirst the or she ate spicy chi
ps with salsa) or low thirst the or she drank Gatorade). Group cohesion was
created by having participants discuss and solve a winter survival problem
, and providing success feedback. Participants withdrew gallons of water fr
om a simulated community water well. The amount of water each participant a
cquired at the end of the trials was converted to a corresponding amount of
a soft drink. The hypothesis was supported. Additional findings showed tha
t participants who had the greatest need for the resource perceived their p
artner as being more honest, trustworthy, and responsible than those who ha
d low need for the resource. The findings support the need principle. Futur
e research should examine how individual and structural variables influence
the emergence and influence of the need norm.