Forensic Psychology For Dummies (87 page)

Another commonly used projective procedure is the Thematic Apperception Test (TAT), in which a set of ambiguous pictures is presented and the respondent is asked to tell a story that each picture illustrates. The pictures may include, for example, a young man sitting on a bed with a woman sitting on the other side of the bed with her back to him, or a young boy on his own with a violin. The themes of the stories created are considered in relation to what they reveal about the needs or desires of the respondent. For example, are the man and woman described as just having had riotous sex, or as a couple who’ve been married for many years and no longer talk to each other? Is the boy described as aspiring to being a concert soloist or as being sad because he can never afford his own violin?

In all projective techniques, the idea is that respondents reveal something about their unconscious or hidden desires and thoughts through the way they interpret the images. Detailed scoring procedures analyse the responses. A simplified example is that someone describing sex and violence in the images may be thought to be revealing the significance of this aspect in their life. By contrast, a person building an interpretation around future aspirations may be assumed to have a mature and forward-looking approach to life.

Many challenges exist to the scientific value of projective techniques. The problem is that if the test is measuring unconscious aspects of the individuals, that they may not even be aware of themselves, what suitable external criteria can be used against which to test the test? The issues that the tester claims are being revealed may never become manifest because, after all, they’re unconscious. An ensuing problem is how anyone can know whether the test is revealing anything other than the tester’s speculations about the person being tested.

Even more challenging is deciding what aspects of the answers to use to generate a sense of what the responses mean. When the given response is very open-ended, such as telling a TAT story or interpreting an inkblot, a real possibility exists that different testers (or even the same tester on different occasions) may identify different aspects of the comments as being important. For example, should the tester give emphasis to the specific part of the inkblot that’s mentioned (for example, the movement or colour) or focus on the content of the meaning? In addition, with what population or sample should the responses be compared to determine whether they’re unusual or significant?

Despite these problems, the Rorschach inkblot test is still very popular and used widely to give court assessments. Psychologists like the idea that an offender can’t know what answers are expected and that any extreme attempts to distort the responses may well be detectable. Also, American psychologist John E. Exner claims to have developed a procedure to overcome challenges to the subjective nature of the Rorschach by providing a precise process for interpreting responses that’s supported by computing technology. A major weakness in this more precise approach, though, is that not every tester follows it, and so courts may be ignorant of the consequences of such negligence on the part of the tester.

Assessing intelligence and skills through performance

Intelligence tests require respondents to complete a number of tasks, usually examining aspects such as verbal skills, mathematical skills and spatial skills. Their distinct quality is that firm right or wrong answers are involved, and so respondents can be assessed on the number of correct answers they give in each area being tested, in turn allowing the comparison of intelligence across each of the areas. If a great disparity results, perhaps it indicates some neurological problem, disturbances in educational background or other aspect of the person that requires more intensive examination.

Psychologists can use simple forms of intelligence tests to estimate brain damage and intellectual competence. Even discovering whether a person has a clear idea of the date, day and time can be a useful indicator, especially if the test is combined with simple arithmetic tasks such as subtracting, say, seven from a series of numbers.

Short-term memory is also a useful pointer to severe mental problems, and psychologists can test for this problem by mentioning three objects and then asking a few minutes later what they were. Psychologists can also incorporate motor movements into such assessments, such as those that were once used to test how drunk a driver was before ‘breathalysers’ became common – for example, touching the nose with a finger or grabbing the left ear with the right hand (close your eyes and try these tasks yourself after a few drinks!).

Many psychologists carry with them specially designed blocks of different shapes and colours and other test equipment, such as components of pictures, which are parts of standard testing procedures. These kits have been developed to explore particular aspects of a person’s abilities and are often used in conjunction with neurological measurements such as brain scans.

Standardising psychological tests

The most structured and fixed of psychological assessment methods are known as
standardised
tests. The standardisation process consists of having the test completed initially by hundreds of people, sometimes thousands, in order to create a starting point for comparison. Their responses are then analysed in relation to each other and to other external criteria.

The classical illustration is the development of IQ tests. The number of correct answers given by children of each age is calculated, so that any given child can be compared with others of the same age. To make a child’s score on the test easily interpretable, the average score for each age group is set at 100, so that a score of 59, as in Daryl Atkins’s case that I describe in the nearby sidebar, can be seen as far below average. The statistics allow the precise calculation that less than 1 in 100 of the population has an IQ of 59 or below. A value this low has been found to be typical of people who can’t really take advantage of most schooling and are generally regarded as unable to make a lot of sense of what goes on around them. (I talk more about IQs in the later section ‘Achieving precision: The need for norms’.)

Standardised measuring instruments provide the backbone to a lot of forensic psychology activity, not least because the courts are more comfortable with a view based on a standard procedure that many professionals agree is appropriate. Tests also provide a standardised framework for describing a person, thus making the preparation of a report much easier than searching afresh for relevant and appropriate terms.

A standardised psychological test widely used in the forensic context, especially in the US, is the Minnesota Multiphasic Personality Inventory (MMPI). This test comes in a number of versions, but the standard form consists of 567 statements which respondents have to decide are true or false as regards themselves. The MMPI takes between 60 and 90 minutes to complete and features statements such as: