Series of his paintings have commonly been used as examples in psychology textbooks to putatively show the change in his style as his psychological condition deteriorated. However, given that Wain did not date his works, it is not known if these works were created in the order presented in textbooks, which typically show more florid, abstract pictures as appearing later, indicative of Wain's mental state. Rodney Dale, the author of "Louis Wain: The Man Who Drew Cats", has criticized this characterization and argued that "Wain experimented with patterns and cats, and even quite late in life was still producing conventional cat pictures, perhaps 10 years after his 'later' productions which are patterns rather than cats."