A report in the journal Science says that imagination may not belong only to humans. Researchers from Johns Hopkins University and the University of St. Andrews studied a bonobo named Kanzi to learn if apes can understand pretend situations. Imagination means acting as if something is real, even when it is not. In the past, some wild chimpanzees used sticks in ways that looked like pretend play, but this study gives the first clear data about this ability in apes. The results suggest that some animals may also have creative thinking skills.

In the study, scientists poured invisible liquid into cups during simple tests. Kanzi chose the correct cup 68 percent of the time. This showed that the bonobo could understand the idea of something that could not be seen. To make sure Kanzi was not confused, the researchers then offered real juice and a pretend option. Kanzi chose the real juice in 80 percent of the tests. This showed that the bonobo knew the difference between real and pretend. Some scientists say more studies are needed, and they believe the laboratory setting may affect the results. Even so, the study is an important finding in animal psychology.