The Rorschach test involves a subject being presented with a set of 10 ambiguous inkblots printed on card paper, each with a near-perfect symmetry to them. They are then invited to offer their perceptions of them, which are recorded and analysed by an administrator. It was a technique widely used, particularly back in the 1960s, as a way to help a person reveal hidden emotion and internal conflicts which they presumably project through their interpretation of the shapes.

In his 2017 book The Inkblots: Hermann Rorschach, His Iconic Test, and the Power of Seeing, author Damion Searls says the psychologist’s now famous inkblots are “probably the 10 most interpreted and analysed paintings of the 20th century”.

“Of the large number of diagnostic tools available to clinicians today, perhaps none has been so widely used yet remained so controversial as the Rorschach test,” says Rorschach scholar John E. Exner Jnr, with Beth Clark, writing in a 1978 edition of the journal Clinical Diagnosis of Mental Disorders.

Exner and Clark report that, since the publication of Psychodiagnostik in 1921, dozens of books and more than 5000 articles have been written on the test.

They note that during its existence, “five major systems of Rorschach administration, scoring, and interpretation have arisen. Each approach offers its own unique postulates, yet each unavoidably adds to the confusion about the uses and the philosophy of the test.”

Hermann Rorschach was born in Zurich, Switzerland, on 8 November 1884. His father was a painter and art teacher, whose young son “showed great interest in drawing from a young age”, according to Ricardo Vieira Teles Filho, a researcher from the Federal University of Goias, in Brazil.

Filho says Rorschach was especially fond of klecksography, “a popular game among schoolchildren at the time, which consisted of filling a piece of paper with ink and then folding it, thus obtaining singular and fun figures”.

Searls adds: “In a twist of fate that seems too good to be true, Rorschach’s nickname in school was ‘Klex’ [or klecks], the German word for ‘inkblot’.”

Searls says that when it came time to move into secondary education, Rorschach had the choice of art or science. Having made the acquaintance of Prussian academic Ernst Haeckel, Rorschach was inspired by the renowned proponent of Darwinism to take up the study of medicine.

Rorschach enrolled in medical school at the University of Zurich, graduating in 1909, which, Filho notes, coincided “with the widespread dissemination of research on the new ideas of a then unknown psychiatrist, Sigmund Freud”.

He then went to work at a local mental hospital while he finished his doctoral dissertation in 1912, under psychiatrist Eugen Bleuler, who coined the term “schizophrenia” and is regarded as “one of the most influential psychiatrists of his time”.

His dissertation didn’t focus on inkblots, but rather examined hallucinations in schizophrenia. Also in 1912, Rorschach published a paper, “Reflex Hallucinations and Symbolism”, and was a co-founder of the Zurich Psychoanalysis Society.

In 1914, he specialised in psychiatry at the University of Zurich, and from 1915 to 1922 he worked in a hospital as chief physician. It was between the years 1917 to 1920 that Rorschach created, refined and studied his inkblots, developing his approach after studying more than 400 subjects’ responses to early versions of them.

His final set of 10 stimuli was published in 1921. Before publication, Rorschach experimented with 40 or more versions of inkblots, many of which appear to be less complex, nuanced and detailed than the final set.

Researchers agree they were artistically embellished by Rorschach himself to ensure that each figure contained numerous distinctive features that could easily be identified as similar to objects stored in the memory traces of any individual.

“Thus,” write Gregory Meyer and Donald Viglione, “despite common belief to the contrary, the images are not arbitrary, haphazard, or accidental inkblots. Instead, they are purposively altered images that were refined through trial-and-error experimentation to elicit informative responses.”

They describe the inkblots as each having a white background: five are grey or black, two are “achromatic” red, and three are “in an array of pastel colours without any black”.

Just a few months after Psychodiagnostik’s publication, Rorschach died, on 2 April 1922, of peritonitis, by several accounts the result of a ruptured appendix.

Despite its popularity, the Rorschach test has attracted considerable controversy, much of it based on the many and various methods of scoring and analysing responses.

Writing in 2001 in the journal Psychological Assessment, Donald Viglione says, “A large body of empirical evidence supports the reliability, validity and utility of the Rorschach. This same evidence reveals that the recent criticisms of the Rorschach are largely without merit.”