A new research has suggested that Shakespeare's plays reveal his psychological signature.

Applying psychological theory and text-analyzing software, researchers at the University of Texas at Austin have discovered a unique psychological profile that characterizes Shakespeare's established works and this profile strongly identifies Shakespeare as an author of the long-contested play 'Double Falsehood.'

Researcher Ryan Boyd said that research in psychology has shown that some of the core features of who a person is at their deepest level can be revealed based on how they use language. With the new study, they show that you can actually take a lot of this information and put it all together at once to understand an author like Shakespeare rather deeply.

The study goes beyond examining authorship from the standpoint of word counts and linguistic regularities, providing a deeper exploration of an author's psychological profile.

Boyd explained that this research shows that it is indeed possible to start modeling peoples' mental worlds in much more complete ways. They can figure out what type of person Shakespeare was very accurately just based on how he wrote using methods that are objective and easy to do.

Double Falsehood was published in 1728 by Lewis Theobald, who claimed to have based the play on three original Shakespeare manuscripts, which have since been lost, presumably destroyed by a library fire, and authorship of the play has been hotly contested ever since.

Some scholars believe that Shakespeare was the true author of Double Falsehood, while others believe that the play was actually an original work by Theobald himself that he tried to pass off as an adaptation.

Researchers examined 33 plays by Shakespeare, 12 by Theobald, and 9 by John Fletcher, a colleague (and sometime collaborator) of Shakespeare. The texts were stripped of extraneous information (such as publication information) and were processed using software that evaluated the works for specific features determined by the researchers.

Looking at the plays as whole units, every measure but one identified Shakespeare as the likely author of Double Falsehood. Theobald was identified as the best match only when it came to his use of content words, and even then only by one of the three statistical approaches the researchers used.

The study appears in Psychological Science.