Adults from the mainland United States are tricked by the Ponzo illusion, whereas Guam citizens are often not fooled by it. This is best explained by

Question

Quizplus · Accepted Answer

Guam citizens likely have less exposure to linear perspective cues, which are necessary for the Ponzo illusion to occur. Therefore, their lack of susceptibility to the illusion is likely due to learning-based inference, rather than factors such as Gestalt psychology, heredity, or the laws of continuity and Pragnanz.

Adults from the Mainland United States Are Tricked by the Ponzo