The situation was further complicated by the arrival of evolutionary psychological thinking in linguistics, with Steven Pinker, Ray Jackendoff and others hypothesising that the human language faculty, or universal grammar, could have developed through normal evolutionary processes, thus defending an adaptational explanation of the origin and evolution of language. This brought about a functionalism‒formalism debate, with Frederick Newmeyer arguing that the evolutionary psychological approach to linguistics should also be considered as functionalist.[10]