In modern societies, occupation is usually thought of as the main determinant of status, but other memberships or affiliations (such as ethnic group, religion, gender, voluntary associations, fandom, hobby) can have an influence. Achieved status, when people are placed in the stratification structure based on their individual merits or achievements like education or training, is thought to be reflective of modern developed societies. Consequently, achieved status implies that social mobility in a society is possible, as opposed to caste systems characterized by immobility based solely on ascribed status.