Beethoven and Franz Liszt, and the results indicate that negative emotions had a causal impact on the creative production of the artists studied. Psychological stress has also been found to impede spontaneous creativity. In fact, Dr. Robert Epstein describes it as a creativity killer. Instead, people must work to cultivate creativity like any other skill. He found that capturing your ideas, seeking out challenges, increasing your knowledge, and surrounding yourself with others who do the same help creativity grow rather than focusing on your stress. A 2005 study at the Stanford University School of Medicine measured creativity by showing children figures of varying complexity and symmetry and asking whether they like or dislike them. The study showed for the first time that a sample of children who either have or are at high risk for bipolar disorder tend to dislike simple or symmetric symbols more. Children with bipolar parents who were not bipolar themselves also scored higher dislike scores. A study by Sally Anne Gross and George Musgrave suggested that high levels of self-reported anxiety and depression amongst musicians might be explained, at least in part, by the nature of their working conditions. Mood and creativity There have been many studies on the correlation between mood and creativity with very different results. Some studies seem to show a correlation between positive mood (affect) and heightened creativity. Other studies show that negative moods seem to be correlated with heightened creativity. One such research paper concludes, "Negative moods signal that the status quo is problematic and that additional effort needs to be exerted to come up with new and useful ideas". The debate is not binary with some studies saying that both positive and negative emotions play a role in creativity "the data support a positive-mood-enhances creativity generalization. Although other components of the creative process suggest a role for negative mood...". What is clear is that the connection between mood and creativity is rarely direct; rather, it's that being in certain moods forces or fosters people into certain actions that make them more creative at the moment. For instance, negative emotions have been shown to increase the amount a person will reflect and ruminate which then can cause a person to be more creative. Studying creativity has its challenges because creativity doesn't necessarily involve action, which is a necessary component for proper research. What is actually being studied is, more appropriately called,