There is support from a meta-analysis for commitment as a variable for relationship maintenance.Le analysed 38,000 participants from 137 studies over 33 years and found commitment a strong predictor of staying in a relationship.This is a strength as provides evidence for commitment being an important variable therefore increasing the validity of the model.Strong real world application for this model across cultures and contexts.Research from US, Netherlands and Taiwan found the three elements of the investment model are found to be predictors of relationship satisfaction.This is a strength as it shows the model has cross-cultural validity and therefore is a representative of relationship maintenance in both individualistic and collectivistic cultures.Investment model provides evidence of why people stay in inequitable relationships, something which the equity theory and social exchange do not.e.g. if a person lacks good alternatives they are more likely to stay with their abusive partner.This is a strength as helps explain vulnerable people behaviour and understanding is the first step to helping.