Doesn’t account for cultural differences. Social penetration theory was based on research in a Western, individualist culture, so it may not apply to collectivist cultures. Tang et al 2013 found that men and women in the USA disclosed more sexual thoughts and feelings than those in China, however the level of relationship satisfaction was high in both cultures. This demonstrates that social penetration theory is culturally biased and self-disclosure is not a requirement for successful relationships in all cultures.