The audience effect attempts to explain psychologically why the presence of an audience leads to people performing tasks better in some cases and worse in others. This idea was further explored when some studies showed that the presence of a passive audience facilitated the better performance of a simple task, while other studies showed that the presence of a passive audience inhibited the performance of a more difficult task or one that was not well practiced, possibly due to psychological pressure or stress. (See Yerkes–Dodson law.)