A further limitation is that Duck’s phase model can be criticised for lacking cultural relativism as most of the research is carried out in Western cultures. Relationships in these cultures are generally voluntary and often come to an end. However, relationships in collectivist cultures are more likely to be compulsory, and involve wider family. For example, they will speak to their family about a problem before their partner. This suggests that Duck’s phase model of relationship breakdown is not applicable to all relationships across all cultures, lowering the external validity of the theory.