Forensic psychology facts and fiction

Forensic psychology may be one of the most misunderstood areas of psychology. TV shows and movies depict brilliant individuals with psychic-type abilities who scan a crime scene and quickly deduce who committed the crime, or briefly interview a suspect and know whether they are lying. 

In reality, forensic psychologists apply evidence-based psychological knowledge to support the criminal justice system in areas such as crime-solving and assessing risk of violence. Importantly, they also understand that many of the tools and methods they use are not infallible. For example, while TV shows/movies may depict forensic psychologists assessing whether someone is lying, a real forensic psychologist would know that there is no 100% accurate method for detecting lies. In fact, research suggests that the general public and law enforcement are likely much worse at detecting lies than they think they are.

Lie detection

Research shows that, when tested, most people perform at chance levels (i.e., a coin-flip decision would be as accurate) when trying to determine whether someone is being dishonest. Despite this, research also shows that many people are confident in their lie-detection abilities, particularly law enforcement personnel. 

There is very little Australian research with police, but a large-scale study published in 2011 showed that the officers (particularly detectives) were very confident in their lie detection ability, yet many were using methods that forensic psychology research shows are unreliable and can contribute to wrongful convictions. 

It’s important that scientific research on lie detection be shared with law enforcement and that the general public be made aware of forensic psychology research, as they may one day make a credibility decision that could seriously affect another person and the community at large if they serve on a jury. This is why forensic psychologists (and psychologists in general) must stay up-to-date on the latest research, and why some people who are interested in forensic psychology decide to become researchers. 

 When studying forensic psychology, it’s helpful to examine the history of specific procedures and tools, as this can show how overreliance on assumptions about accuracy can be harmful. It can also highlight that some tools were developed with bias or prejudice. A historical example of this is profiling, as seen in the witch hunts of early modern Europe. 

Historical applications of criminal profiling

Criminal profiling involves identifying a criminal’s characteristics based on the crime type and/or the crime scene. Around 1486, two monks published a Latin book titled the Malleus Maleficarum (English: “The Witches’ Hammer”). This book was written to help identify, prosecute, and punish witches. According to the book, many, if not most, women were evil, and it was stated that witches could be identified.

Witches were described primarily as women who:

1. have a spot, scar, or birthmark, sometimes on the genitals and sometimes invisible to the Inquisitor’s eye
2. live alone and keep pets (a demon in animal form known as a familiar)
3. suffer the symptoms of mental illness (auditory or visual hallucinations, etc.)
4. cultivate medicinal herbs
5. have no children

Proof of evidence that someone was a witch was not required. If the accuser was credible (e.g., an upstanding citizen in the community), their word was enough. Anyone who tried to defend an accused witch (i.e., make a statement that the person was not a witch) was considered an accomplice. Witches were tortured and killed (e.g., burned at the stake). 

Think about this, if you’re a woman, how many of these criteria do you fulfil now or in the past? Think about the women you know, how many would have some or all of these criteria? What is shocking to know is that in some countries, some people still believe in witches and ‘witch lynching’, killings without a formal trial, still occur. Another area of forensic psychology related to criminal profiling that has evolved from a dubious past is the study of personality and crime. 

Personality and crime

Personality is defined as an enduring and stable pattern of thinking, feeling and acting. While Ancient Greek and Chinese physicians and philosophers described specific characteristics of some people, arguably the most widely popularised theory of personality and its connection to deviant behaviour and criminality was Phrenology.

German-born physician and academic Dr Franz Gall introduced the so-called science of Phrenology in Europe early in the nineteenth Century. Vienna built its largest hospital and adjoining insane asylum while Gall attended Vienna’s medical school. Gall was a member of a large academic cohort interested in cognition (e.g., how people think, remember, acquire knowledge, and make decisions, etc.). 

The prevailing theory of the time was that all cognitive processes involve whole-brain activity. Gall developed an idea, derived from research on animal behaviour, that different human actions resulted from the functioning of separate “organs of the brain”. Gall noted that people with similar capabilities and/or characteristics shared similar facial and cranial features (e.g., protruding eyes and superior memory). Gall theorised that this was not coincidental. Gall had access to the hospital and the asylum, and after befriending Vienna’s police minister, he also gained access to the prison. 

Gall then studied the facial and cranial features of mentally disordered and antisocial people (e.g., murderers) who were residents, or detainees, at these facilities. He made post-mortem (after death) observations and began collecting skulls of the deceased (and making wax and plaster casts) from approximately 1792. A decade later, Gall had collected the skulls of 300 people, many of whom were criminals. 

Gall proposed a theory of brain physiology that explained human actions, ranging from exemplary (e.g., noble, generous, clever, and kind) to deviant (e.g., dishonest, cruel, and criminal). He created a 27-item list of human behaviours that were observable through analysis (by feel or sight) of the face and cranium. Gall’s theory was claimed to be scientific, as it involved a comparison of the observable and recordable, being skull shape and behaviour. He spoke and wrote extensively about his idea. 

However, in 1801, Emperor Franz II banned Gall’s publications and speeches, citing moral and religious concerns. This ban had the opposite intended effect. Curiosity about Gall’s theory increased from 1802, leading him to commence lecturing across Europe in 1805. Gall became internationally acclaimed, and Phrenology spread throughout Europe. By the 1830s, phrenological books, pamphlets and societies had spread throughout Britain. Phrenology soon spread to other countries.  

Phrenology provided a very well-paid profession for practitioners, many of whom were untrained. Phrenologists delivered free presentations that advertised paid private readings for those who wanted information about others (e.g., parents planning whom their daughter would marry). Phrenologists profited from an unscientific method of determining the personality and likely behaviours of humans. 

Phrenology was presented as meeting the tenets of science, yet, like other methods of predicting people’s likely behaviour (e.g., astrology), it lacked scientific rigour. For example, many physicians investigated Gall’s claims by examining patients’ heads and found inaccuracies in Phrenology. Gall dismissed the physicians’ claims and only favoured evidence that supported his theory. Eventually, Phrenologists’ claims were proven incorrect, and the overselling of Phrenology pre-empted its demise.

However, Phrenology was a groundbreaking finding in understanding human cognition: that different areas of the brain are involved in various actions and abilities. Further, research on personality disorders and crime shows that people with antisocial personality disorder and psychopathy are more likely to commit crimes than people without these disorders. This has been an expanding area of research since Fazel and Danesh (2002), in a review of nearly 23,000 offenders, found that 65% of men and 47% of women were identified as having one or more personality disorders. 

While we shouldn’t be assessing head bumps to predict who is a criminal, research suggests it may be helpful to assess if someone is a psychopath or has antisocial personality disorder if you are trying to predict criminal behaviour.

Advice for those interested in becoming forensic psychologists

Modern forensic psychology is evidence-based, and critical thinking is an important skill to acquire. History shows how dangerous unsupported methods can be, and those interested in becoming forensic psychologists can take the first step by developing their critical thinking skills and learning scientific methods. 

If someone is interested in becoming a forensic psychologist, the process in Australia involves completing a psychology undergraduate degree or a dual degree in psychology and criminology (3 years), then a one-year honours degree, after which students complete a two-year forensic psychology master’s. If someone wants to be a forensic psychology researcher and academic (i.e., a university lecturer who conducts research), they could complete a PhD (3-4 years) rather than a master’s. 

While the learning journey is long, forensic psychology is a fascinating field and an exciting area for research, with much still to be discovered. If someone decides to become a forensic psychology researcher, my personal experience gives me confidence that they will never be bored. 

Dr Rebecca Wilcoxson is a forensic and social psychology lecturer at the School of Health, Medical and Applied Sciences at CQUniversity Australia. Her primary area of research is lie detection.

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