In order to succeed in the task, children had to take into account the psychological properties of Robber and King, including person-specific characteristics, intention, perception, knowledge, and belief. For example, Robber the competitor, who was nasty and intended to take away the treasure, would see the trails, which children inevitably left when hiding the treasure, and would know where to get the treasure. Children by the age of 3 years already understand the relationship between seeing and knowing (Pratt & Bryant, 1990) but it is a challenge for them to take advantage of this relationship to hinder or help someone to find something (Sodian et al., 1991). For example, a child could remove the trails so that Robber would not know where the treasure was or s/he could lay false trails so that Robber would falsely believe the treasure was somewhere else. Alternatively, s/he could enhance the trails or even open the boxes to let King, the nice cooperator, know the location of the treasure. By altering what Robber and King would see, know, and believe, children manipulated their minds. Children who either hindered Robber or helped King would be scored as a ‘1′ and children who both hindered Robber and helped King were scored as a ‘2.’