-investigated when perspective-taking happens, asked ppts to take the role of different people.
-60 ppts: 30 boys; 30 girls; 20 aged 4; 20 aged 5; 20 aged 6.
-gave ppts a scenario: Holly promised her dad she wouldn't climb up trees but a friend's kitten is stuck in a tree and she is the only one who can climb high enough to get it. Then asked them questions about how others would feel e.g., if she didn't save the cat. Tested individually. Asked different questions e.g., 'should Holly be punished if she climbs the tree?'
-found that the level of perspective-taking was distinct based on age, correlated with age, clear developmental sequence.