Read Forensic Psychology For Dummies Online
Authors: David Canter
Forensic Psychology For Dummies (8 page)
Defending a mayor from a charge of obscene behaviour
Professor Lionel Haward (1920–98) is the father of forensic psychology in the UK and gave evidence in many cases, often using procedures derived from experimental psychology as the basis for his evidence.
One particularly interesting (not to say amusing) case was when Haward acted for the defence of a local mayor who was accused of indecent exposure in a public toilet. This charge resulted from two police officers following up complaints of indecent activities by hiding themselves in a cubicle in the public conveniences, peering through a grill in the door.
The defendant claimed that he’d been wearing a pink scarf at the time and that the enthusiastic police officers, keen to make an arrest, were so primed to expect indecency that they misinterpreted this innocent apparel for a part of his anatomy!
Haward set up an experiment in which naïve subjects were shown photographs under limited lighting conditions of the mayor wearing his scarf. The subjects were given the expectation that something untoward was illustrated in the pictures and asked to indicate when they saw it and what it was.
Haward found that one picture in every eight was believed to represent an indecent act. Haward offered these results together with an explanation of the psychological processes involved and citation of other studies illustrating the power of expectancies on the interpretation of ambiguous images. The attorney used this report as the basis for invalidating the police evidence. The mayor was acquitted.
As early as 1908, Harvard Professor of Psychology Hugo Münsterberg published a book with the modern sounding title
On the Witness Stand
, in which he described the various ways in which the discoveries of the newly emerging discipline of psychology were of relevance to expert evidence in court. Many of the topics discussed are still relevant today, such as the fallibility of witnesses’ memories, false confessions and how the court process itself can influence what people admit to. (Check out Chapter 4 for much more on memory and witnesses.) In Germany in 1909, where psychological research was also very active, Clara and William Stern published a book that considered children’s ability to remember and give effective testimony as well as examination of the various psychological processes that may give rise to false testimonies.
A recurring interest in the psychology of lying and deception and the possibility that physiological changes in the person can reveal such deception was an early application of laboratory-derived ideas to forensic considerations. In 1915, William Marston, a student of Münsterberg, introduced the first ‘lie detector’ that measured a person’s blood pressure when answering questions about a past event. Within a few years similar procedures were being used successfully in criminal investigations. This laid the groundwork for many procedures that are in use today. I talk much more about deception in Chapter 6.
Following on from the work of the early pioneers in psychological research, an increasing number of psychological studies of relevance to the law were carried out. Examining psychological issues relating to testimony and deception have become the cornerstone of this work. But broader issues such as beliefs about rape, or social psychological aspects of jury decision-making, have now taken this far beyond those explorations a century ago.
The clinical strand
Alongside the academic explorations of human behaviour and experience that I describe in the preceding section, people working directly with patients in a clinical context have, from early in the 20th century, contributed to various aspects of legal proceedings.
Lionel Haward was a clinical psychologist carrying out therapy with patients. Some of his patients came to him through the courts, for assessment or treatment, and out of that contact he was called on to give expert evidence. He drew on psychological procedures as illustrated in the sidebar ‘Defending a mayor from a charge of obscene behaviour’, but as with most clinical psychologists his main contribution to court procedure was from the point of view of a clinician offering an informed, objective opinion about a patient.
Giving testimony
One of the founders of modern, scientific psychology was J. McKeen Cattell, working at Columbia University in the 1890s. He was very interested in how people remember and how accurately they could recall what had happened. He thus set in motion the study of the psychology of testimony that has grown ever since and thrives today.
The Tories in my native city have compelled me to do this. They follow and persecute me wherever I go, and have entirely destroyed my peace of mind.
This claim was taken to mean that McNaughton was mentally disturbed, causing a furore in the British legal system at the time.
To understand this case, I need to introduce a couple of legal Latin terms.
For a person to be convicted in most places in the world, certain conditions need to be satisfied:
Actus reus
– meaning that the act did actually occur (or some crime was committed because an action did not occur).