group attribution error
the tendency for perceivers to assume that a specific group member’s personal characteristics and preferences, including beliefs, attitudes, and decisions, are similar to those of the group to which he or she belongs. For example, observers may assume that an individual who is a member of a group that publicly announces its opposition to an issue also opposes the issue, even though the group’s decision to take the stated position may not have been unanimous. See also group fallacy; outgroup homogeneity bias. [originally described in 1985 by U.S. social psychologists Scott T. Allison and David M. Messick]