The study by Onishi and Baillargeon (2005) investigates whether 15-month-old infants understand false beliefs. Traditional research suggests that young children, particularly preschoolers, struggle with tasks that require understanding false beliefs, indicating a lack of a "theory of mind." However, some researchers argue that this ability is present earlier and that difficulties in standard false-belief tasks may be due to excessive task demands. To test this, the researchers used a nonverbal violation-of-expectation method. Infants watched an actor hide a toy in one of two boxes and then either had a true or false belief about the toy's location. In the test trials, the infants were shown the actor searching for the toy in either the correct or incorrect box. The results showed that the infants looked longer when the actor's search did not align with her belief about the toy's location, regardless of whether the belief was true or false. This suggests that 15-month-old infants have an implicit understanding of false beliefs, supporting the idea that they possess a representational theory of mind from a young age. The findings have implications for understanding atypical development, such as autism, and animal cognition, suggesting that nonverbal false-belief tasks could provide new insights into these areas.The study by Onishi and Baillargeon (2005) investigates whether 15-month-old infants understand false beliefs. Traditional research suggests that young children, particularly preschoolers, struggle with tasks that require understanding false beliefs, indicating a lack of a "theory of mind." However, some researchers argue that this ability is present earlier and that difficulties in standard false-belief tasks may be due to excessive task demands. To test this, the researchers used a nonverbal violation-of-expectation method. Infants watched an actor hide a toy in one of two boxes and then either had a true or false belief about the toy's location. In the test trials, the infants were shown the actor searching for the toy in either the correct or incorrect box. The results showed that the infants looked longer when the actor's search did not align with her belief about the toy's location, regardless of whether the belief was true or false. This suggests that 15-month-old infants have an implicit understanding of false beliefs, supporting the idea that they possess a representational theory of mind from a young age. The findings have implications for understanding atypical development, such as autism, and animal cognition, suggesting that nonverbal false-belief tasks could provide new insights into these areas.