Shakespeare identified as author of disputed play

English playwright William Shakespeare has been identified as the true author of a long-contested play published nearly 300 years ago and believed to be an adaptation of the bard's work, scientists say.
Applying psychological theory and text-analysing software, researchers have discovered a unique psychological profile that characterises Shakespeare's established works, and this profile strongly identifies Shakespeare as the author of 'Double Falsehood'.
"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," said researcher Ryan Boyd of the University of Texas at Austin.

"With our new study, we 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," said Boyd.
The study, conducted in collaboration with James Pennebaker, also at UT-Austin, provides a deeper exploration of an author's psychological profile.
Double Falsehood was published in 1728 by Lewis Theobald, who claimed to have based the play on three original Shakespeare manuscripts.

The manuscripts 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.

Boyd and Pennebaker realised that using psychological theory to inform analysis of the playwrights' respective works may shed light on the authorship question.
They examined 33 plays by Shakespeare, 12 by Theobald, and 9 by John Fletcher, a colleague 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.
For example, a software examined the playwrights' use of function words (eg, pronouns, articles, prepositions) and words belonging to various content categories (eg, emotions, family, sensory perception, religion).
By aggregating dozens of psychological features of each playwright, Boyd and Pennebaker were able to create a psychological signature for each individual.

They were then able to look at the psychological signature of Double Falsehood to determine who the author was most likely to be.
Looking at the plays as whole units, the results were clear: Every measure but one identified Shakespeare as the likely author of Double Falsehood.
The research was published in the journal Psychological Science.