When faced with specific challenges, three-year-olds approach problems from a single perspective. They haven’t yet developed the ability to see an issue from two angles or to consider multiple aspects of a problem before making a decision. These complex reasoning skills don’t fully develop until around age 7.
Shelov, S. P. (Editor-in-Chief). (2004). Caring for Your Baby and Young Child: Birth to Age 5. The American Association of Pediatrics. Revised edition. New York: Bantam Books.