Multiple alternatives have advocates. The contrary constructivist position holds that human faculties and concepts are largely influenced by socially constructed and learned categories, without many biological restrictions. Another variant is idealist, which holds that human mental capacities are generally unrestricted by biological-material strictures. Another is essentialist, which holds that essential differences may influence the ways individuals or groups experience and conceptualize the world. Yet another is relativist (Cultural relativism), which sees different cultural groups as employing different conceptual schemes that are not necessarily compatible or commensurable, nor more or less in accord with external reality.