The idea of the reference group effect to be based on the notion that people make implicit social comparisons with others when making ratings on scales, rather than relying on direct inferences about a private, personal value system
was revealed by Peng, K., Nisbett, R. E., Wong, N. Y. C. (1997) in their article "Validity problems comparing values across cultures and possible solutions. Psychological Methods, 2(4), 329-344"
The Reference-group effects are found to occur when there are reponses to self-report issues which are not related to the respondents' absolute level of construct. It is usually on their level that is relative to a salient comparison group.
Slavery weakened the roman republic because Spartacus decided to fight the roman guards because he thought him and his people shouldn't have to die as gladiators so they ran away and caused much chaos
