Population validity – Kohlberg used participants from 6 different countries which means that his study could have PV as it represents cultures from different parts of the world.
There was a limited number of participants (75 in the USA, not declared in the other participant groups), group can be seen to be unrepresentative of the USA and cultures across the world.
Only contained males - beta bias - Gilligan identified female moral reasoning is based more on care and compassion rather than male based principles of law and justice.
