Various educators have estimated that Esperanto can be learned in anywhere from one quarter to one twentieth the amount of time required for other languages.[86] Claude Piron, an Esperanto-Activist and Chinese–English–Russian–Spanish translator for the United Nations, argued that Esperanto is far more intuitive than many ethnic languages: "Esperanto relies entirely on innate reflexes [and] differs from all other languages in that you can always trust your natural tendency to generalize patterns.... The same neuropsychological law [—called by] Jean Piaget generalizing assimilation—applies to word formation as well as to grammar."[87]