real identity of an object in order to treat it with its pretend identity varies with age and what attributes the child needs to ignore, form and/or function. Overall, prior research has shown that pretend play activities can improve a child's executive function, but whether the act of pretending or some other part of the activity such as practice inventing a story or building a fortress is responsible is still an open question. Learning and knowledge acquisition Pretend play is not only associated with developing general cognitive abilities and reinforcing existing knowledge, but recent research has been investigating how children learn new knowledge during pretend play. While children do not invent new knowledge on their own, when pretending with others, children make judgements about the generalizability of unknown information introduced by others in the pretend context. These judgements affect the degree to which children believe the information is applicable and reflective of the real world. There are a number of factors known to influence these judgements including the fantastical themes employed in the pretend world as well as the credibility of the other play participants. Emotions By the age of three, children are generally able to distinguish fantasy and pretense from reality, but there are a number of reasons why children might confuse the two. In some cases, it appears as though children are unable to regulate their emotions, especially fear, and this leads to what may seem like confusion between reality and pretense, such as monsters hiding in their toy bin. Negative emotions such as fear and anger also seem to have a negative effect on children's tendency to believe an event is either possibly real or fantasy and either more or less likely to actually happen in reality. Prior knowledge From ages as early as 15 months, children demonstrate both an understanding of pretense and expectations of reality being reflected in pretense. At times, pretend play may involve animals, objects, or places that the child knows little or nothing about, and any information about these subjects that is introduced during the pretend play is readily associated with the subject. However, when the child has some knowledge about the subject of pretense, like being familiar with the behavior of lions, and new information is introduced that is contrary to their knowledge, such as lions only eat animal crackers, they are less likely to learn this information as being generally