Age disparity in sexual relationships and sexual relationships between individuals of a significant difference in age have been documented for most of recorded history and have been regarded with a wide range of attitudes, from normalized acceptance to taboo. Concepts of these relationships and of the exact definition of a "significant" age disparity have developed over time and vary between societies, legal systems (particularly with regards to the age of consent), and ethical systems. These views are rarely uniform even within cultures and are affected by views of consent, marriage, and gender roles, and by pe****tions of social and economic differences between age groups.