Crime has a long history in human society. Just as Willhelm Wundt is considered the father of psychology, Hugo Münsterberg is considered to be one of the first to bring psychology into the courtroom. Why people commit crimes whilst others forgo a life of crime has interested psychologists for a long time.

The need to understand the reasons behind criminal behaviour, how to catch a criminal, and, more importantly, how to prevent crime became obvious. This is where forensic psychology comes in.

• We are going to explore the world of forensic psychology.
• First, we will provide a forensic psychology definition, clarifying what we mean by forensic psychology.
• We will then explore the various forensic psychology methods, such as offender profiling.
• Then, we will briefly cover forensic psychology research, namely the biological and psychological explanations for offending behaviour.
• Finally, we will discuss the problems in forensic psychology.

Fig. 1 - Forensic psychology explores the theories behind criminal behaviour

Forensic Psychology: Definition

Forensic psychology is investigative psychology that looks into the psychological theories behind criminal behaviour. Why a person may commit a crime, who they may be and how they act are all factors psychology explores.

Whilst initially, forensic psychology was not a fully respected discipline (Münsterberg faced scepticism in the courtroom by the judge and others present), it has gained credibility and esteem over the years.

Forensic psychologists typically help in the cases of eyewitness testimonies, assessing competency to see if a person is in a sound state of mind to stand trial and help decide appropriate treatment plans and sentencing.

Forensic Psychology Research: Measuring Crime Rates

Crime is an act that violates the law, usually resulting in punishment. What people consider a crime varies from place to place (culture, setting, and time can change the definition of a crime).

It's important for governing bodies to know the true extent of crime rates, and one way to do this is through measuring crime.

Measuring crime rates comes in three forms, mainly:

• Official statistics: Government records of total crimes reported and recorded in official figures.
• Victim surveys: Each year, the Crime Survey for England and Wales sends a survey to 50,000 households asking them to report any crimes they have been victims of in the previous year.
• Offender surveys: Individuals volunteer information about the number and type of crimes they have committed.

Forensic Psychology Methods: Offender Profiling

Offender profiling focuses on accurately predicting the characteristics of unknown criminals through various procedures and is an investigative tool, a core aspect of investigative psychology. There are two main forms of offender profiling: the top-down and the bottom-up approaches.

The top-down approach is used by America, whereas the British use the bottom-up approach.

The Top-down Approach

Developed by the FBI (Federal Bureau of Investigation), the top-down approach classifies criminals into different types, working from the top down. Using data from 36 convicted serial killers and murderers (including the infamous Ted Bundy), the FBI identified organised and disorganised groups.

The top-down approach assumes that criminals show particular behaviours (often known as their modus-operandi or ‘MO’).

The FBI follow four steps when creating profiles (Douglas et al., 1986):

1. Collecting and combining data from the crime.
2. Classifying the type of crime.
3. Hypothesise about what happened and reconstruct the crime.
4. Generating a profile of the offender.

Fig. 2 - America uses the top-down approach in offender profiling.

The Bottom-up Approach

Developed by David Canter, the bottom-up approach uses investigative psychology and geographical profiling to identify possible offenders. There are no typologies. Investigators examine crime scenes, analyse evidence, and talk to witnesses to hypothesise about the likely characteristics of the perpetrator, such as:

1. Personal characteristics.
2. Criminal history.
3. Location.
4. Social characteristics.
5. Career and educational history/level.

Investigative psychology includes details from the crime scene that are matched with psychology theories and analysis of offenders to find the most likely match. Geographic profiling examines crime scenes to determine the offender’s base and possible future crimes.

Fig. 3 - The UK uses the bottom-up approach to offender profiling.

Criminology and Forensic Psychology: Biological explanations

Several biological explanations and theories for criminality exist in psychology (and criminology), such as the atavistic form, and genetic and neural explanations.

Positivist criminology suggests no free will exists in criminal behaviours; our features decide it. Cesare Lombroso described the atavistic form in 1876, which states that criminals are less evolved people or primitive subspecies unfit for modern society.

Lombroso noted that this criminal subspecies could be identified by specific characteristics such as:

• A prominent jaw.
• High cheekbones.
• Drooping eyes.
• Dark skin.
• Asymmetry of the face.

Genetic and Neural Explanations

Psychologists have also tried to find genetic and neural explanations for criminality. Twin studies and candidate genes are essential parts of this process.

• Studies by researchers such as Tiihonrn et al. (2014) have shown that abnormalities in the MAOA and CDH13 genes can predict violent criminal behaviours.

Other psychologists claim that there may be neural differences between criminals and non-criminals.

Forensic Psychology Research: Psychological Explanations

Are murderers born or made? Psychological explanations explore the psychological aspect of offending behaviours, namely identifying issues in the mind of offenders and identifying possible environmental conditions that may explain the behaviours.

Eysenck’s Theory of the Criminal Personality

Eysenck (1964), a critical exponent of personality and intelligence research, stated that behaviour could be divided into three categories: introversion/extroversion (E), neuroticism/stability (N), and psychoticism (P). According to Eysenck, we inherit the extent and type of character traits through our nervous system, which means that criminality could have a biological basis.

• Eysenck explained that the criminal personality type is neurotic-extroverted with a high degree of psychoticism.
• However, Eysenck also stated that criminals are formed by a combination of criminal personality and socialisations, meaning that his approach is a hybrid one, both biological and social.

Thinking Patterns, Levels of Moral Reasoning, and Cognitive Distortions

Several explanations for criminal behaviour suggest that offenders think differently than their peers. They show different thinking patterns, levels of moral reasoning, and cognitive distortions that affect their perceptions of reality.

• The levels of moral reasoning, developed by Kohlberg (1958), refer to the stages of moral reasoning people advance through as they age, affecting their behaviours. According to the theory on moral reasoning, criminals may have a lower level of moral reasoning, meaning they feel less about the morality of their actions.
• Cognitive distortions are information processing/thinking errors that alter a person's ability to perceive reality. Offenders may have cognitive distortions linked to their criminal behaviours (i.e., being self-centred or minimising their behaviours).

Differential Association Theory

Differential association theory, developed by Sutherland (1939), suggests criminal behaviour is a learned interaction where offenders learn the techniques, methods, and motives of criminal behaviours from other criminals.

Cognitive Biases

According to cognitive theory, criminals also have cognitive biases (information processing errors or biases) that influence their behaviour. Two examples are:

• Hostile attribution: Viewing the behaviour as aggressive or threatening when not.
• Minimalisations: Downplaying an event or emotion, e.g., guilt.

Fig. 4 - There are a variety of psychological explanations for criminal behaviours.

Forensic Psychology: Psychodynamic Explanations

Psychodynamic explanations for criminal behaviour explore offending behaviours through the lens of Freud's theories. Blackburn (1993) suggests that the differential development of the superego can lead to criminal behaviour:

• The weak superego: When a child does not identify with a parent, they do not internalise a superego, which leads to immoral or criminal behaviour.
• The deviant superego: If a child internalises an immoral or deviant superego, this can lead to criminal behaviour.
• The overly harsh superego leads to debilitating guilt and anxiety in a child, resulting in criminal behaviour to satisfy the superego’s need for punishment.

Freud also explored defence mechanisms, namely displacement, repression and denial.

Maternal Deprivation Theory

Bowlby (1944) asserts that a child who cannot form a solid attachment to their mother figure is less likely to form meaningful relationships in adulthood and is more likely to develop a personality type of ‘loveless psychopathy’. A lack of guilt, empathy, and feelings for others, all traits associated with criminal behaviour, characterise this personality type.

Dealing with Offending Behaviour

So, the offender committed a crime. What next? Punishment for criminal behaviour can take different forms, from more traditional versions to modern therapeutic approaches.

Custodial sentencing

Custodial sentencing is when the court orders the offender to serve time in a prison or other closed therapeutic/educational facility such as a psychiatric hospital.

The custodial sentence has many purposes :

• Deterrence.
• Incapacitation.
• Retribution.
• Rehabilitation.

It also has many psychological effects:

• Stress and depression.
• Institutionalisations.
• Prisonisation.

In this section, we also address recidivism.

Behaviour Modification in Custody

Behaviour modification in custody applies the behaviourist approach that attempts to replace criminal behaviour with desirable, productive behaviour by using positive/negative reinforcement.

Anger management

Anger management involves a therapeutic program to identify and manage the anger that may have led to criminal behaviour. This process consists of three phases:

• Cognitive preparation.
• Skill acquisition.
• Application practice.

Restorative justice

Restorative justice focuses on reconciliation between offender and victim. The aim is to enable the offender to understand their crime’s impact and empower victims by giving them a ‘voice’.

Problems in Forensic Psychology

Whilst forensic psychology provides multiple techniques to investigate criminal behaviour and identify possible explanations for criminal behaviour, it has problems in itself.

• Some techniques are not as robust. The top-down approach has been criticised for validity issues and generalisability concerns. Research into offender profiling is also surprisingly limited into how effective it actually is.
• Explanations of criminal behaviour have issues with reductionism (particularly biological explanations) and determinism. Psychological explanations also suffer from problems, for example, the psychodynamic approach is not scientifically tested, and Sutherland's (1939) theory on differential association fails to account for individual differences.
• Ethical concerns remain in forensic psychology, as misuse of work, problems with competence, and issues with avoiding harm crop up within forensic psychology.