In the early 20th century, the Swiss psychologist Hermann Rorschach devised a test for examining people’s personalities based on their responses to sets of inkblots. In the Rorschach test, ‘ten and only ten’ inkblot patterns are used, reproduced on cards precisely 9½ inches high and 6½ inches wide. The same image can be replicated on both sides. Subjects are invited to view each inkblot and describe what they see. Their responses to the images are assessed according to several criteria, including level of detail, perceived content (such as a dancing bear) and the impression or otherwise of motion.

Born in 1884 near Zurich, Rorschach was a frequent doodler at school, taking after his father, who was a painter. As a result, he acquired the nickname ‘Klex’, derived from the German word for blot. He studied medicine at Zurich University, where he was lectured by Carl Jung and by Eugen Bleuler, director of the Burghölzli psychiatric clinic near Zurich, where both worked. This clinic housed over a thousand patients and had acquired an international reputation for its enlightened and innovative methods, particularly the ‘affective rapport’ technique recommended by Bleuler. Jung lectured on his word association tests, in which he used a stopwatch to measure the response time to a stimulus word. He had found these tests to be psychologically valuable, coining the term ‘complex’ as a result. Rorschach took note.

Rorschach practised as a psychiatrist at Herisau, near St Gallen, and at the nearby Krombach psychiatric hospital. Here he tried to find ways to connect to his more difficult, often schizophrenic patients. He experimented with showing them his own drawings, forerunners of the later inkblots, and discovered how effective this visual approach was – the ‘power of seeing’, as Damion Searls puts it in the subtitle of his book. For instance, he showed them an inkblot that bore a strong resemblance to a bat, which they interpreted as ‘moving people’, giving him a clue to the pattern of their thought processes. He then moved on to constructing a code, or protocol, to interpret his patients’ reactions. Rorschach died in 1922, but his tests outlived him and caught on particularly well in the USA (where personality definition and, arguably, simplification have always been popular). Searls links this interest with the growth of anthropology in the 1930s. Ruth Benedict, one of this new discipline’s foremost proponents, viewed culture as ‘personality writ large’.

Rorschach’s Psychodiagnostics, first published in Switzerland in 1921, was translated into English and published in the USA in 1942. Its most intriguing use came in the context of the Nuremberg Trials of 1945. As prominent Nazis waited in prison to be brought before the military tribunal and tried for ‘crimes against humanity’, the US authorities sought to make sure that they were mentally competent to stand trial. The prison psychiatrist, Douglas Kelley, was asked to check this. As it happened, he was one of the authors of what was then the leading English-language manual for the Rorschach test. Kelley used Gustave Gilbert, the prison’s morale officer and a fluent German speaker, to help him administer the tests.

Gilbert’s diary records their encounters with the twenty-four Nazi prisoners, who, stuck in their tiny cells for months on end, welcomed any engagement with other people. Several behaved like ‘bright and egotistical schoolboys’ once the tests started, delighted to be spoken to (their guards weren’t allowed to talk to them, even when delivering meals). Göring, in particular, welcomed the challenge, claiming he had learned all about psychological testing from his cousin Matthias Göring, head of the German Institute for Psychological Research and Psychotherapy. Göring had earlier achieved a score of 138 in an IQ test, higher than the level of 130 required to join Mensa. Gilbert’s diary entry for 15 November 1945 describes his reaction to this result: ‘Göring chuckled with glee as I showed surprise at his accomplishment … He could hardly contain himself for joy and swelled with pride.’ As the Rorschach test proceeded, Göring ‘laughed, snapped his fingers in excitement, and expressed “regret” that the Luftwaffe hadn’t had available such excellent testing techniques’. After being found guilty, Göring, he reported, ‘lay on his cot completely worn out and deflated … like a child holding the torn remnants of a balloon that had burst in its hand’. A few days later, he asked Gilbert for the results of his Rorschach test. Gilbert told him that it indicated that he possessed an active, aggressive mind and added:

you lack the guts to really face responsibility. You betrayed yourself with a little gesture on the ink-blot test. Do you remember the card with the red spot? Well, morbid neurotics often hesitate over that card and then say there’s blood on it. You hesitated, but you didn’t call it blood. You tried to flick it off with your finger, as though you thought you could wipe away the blood with a little gesture. You’ve been doing the same all through the trial – taking off your earphones in the courtroom, whenever the evidence of your guilt became too unbearable. And you did the same thing during the war too, drugging the atrocities out of your mind. You didn’t have the courage to face it. That is your guilt … You are a moral coward.

Göring glared back at him and then was silent. Next, with a sweeping gesture, he dismissed all psychological tests, saying they were meaningless. But the Rorschach test had struck home.

Searls adds a curious coda to this episode. On New Year’s Day in 1958 Kelley, by then vice-president of the Society of American Magicians, committed suicide in front of his wife and children by swallowing cyanide from a capsule crushed between his teeth, just as Göring had done. It was rumoured that he had kept this cyanide capsule as a souvenir of Nuremberg, and even that Kelley had supplied Göring with his own cyanide capsule in the first place. Searls handles this episode with admirable dexterity. Elsewhere he provides useful tangential information, helping us to build up a picture of how 20th-century psychology evolved. It is unfortunate for him that Rorschach died at the age of just thirty-seven. Nevertheless, Searls’s explorations of other dimensions of his work are always interesting.

The quest to understand and interpret the mind, with all its intricacies, goes on. In recent decades, neuroscience has furthered our knowledge of brain functions immensely. The Rorschach test is still used in the USA, in courtroom proceedings and parole hearings, but its influence is declining. Doubts about the objectivity of its testers have emerged, as have questions about its tendency to indicate thought disorders. Yet it is still widely referred to; Hillary Clinton and Barack Obama both alluded to it in self-descriptions. This bears out Searls’s claim that it’s still ‘a visual and cultural touchstone’.