Proponents of a Universal Grammar argue that humans are born with a dedicated language system that shapes and restricts the number of grammars found in human languages (Chomsky, 2005). It is essentially innate and has a genetic manifestation. Such an innate system is necessary because human grammars are too complex to be passed on through social interactions and probabilistic learning alone. However, this view is contested by a combination of emergentist approaches and a number of studies suggest that many of the core assumptions of Universal Grammar are either unnecessary or do not hold. Furthermore, this review will explore theoretical criticism of the Universal Grammar research programme.