Question

Trey's older sister is playing a game with him. she hides the ball they are playing with, and trey quickly loses interest in the game. he makes no attempt to look for the ball and instead picks up another toy that is close by. this suggests that trey has not yet developed:

Answer 1

This suggests that Trey has not yet developed a legitimate understanding of the permanency of tangible objects. This can be evidenced by the fact that Trey lost interest in the ball once it was no longer in his range of sight. He has not yet learned that the object does not just disappear if he is unable to see it.