Category: Forensic

Preliminary Evidence That Stress Makes Negative Memories Less Distinctive, With Implications For Witness Testimony 

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By Matthew Warren

Stress has complicated effects on our memories. Whereas some studies have found that we are better at remembering events that occurred during stressful situations, such as while watching disturbing videos, others have shown that stress impairs memory. Now a study published in Brain and Cognition suggests that stress doesn’t influence the strength of our emotional memories at all. Instead, the researchers claim, it is the fidelity of those memories – how distinct and precise they are – that changes when we go through stressful experiences. 

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People’s Sense Of Control Over Their Actions Is Reduced At A Fundamental Level When They’re Angry Or Afraid

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The findings lend some scientific legitimacy to the “I just lost it” defence

By Matthew Warren

During major bouts of anger or fear, people can end up taking extreme and sometimes violent actions. But they often say that, in the moment, they didn’t feel responsible for those actions – they “lost control” or “saw red”. In the UK, under certain circumstances, a person accused of murder can even claim that this “loss of control” led to them killing their victim. If successful, this defence can reduce charges to manslaughter.

Now the first study of its kind suggests that there is some truth to these claims. Participants put into a fearful or angry state really do seem to have a reduced sense of agency, according to a paper published recently in Experimental Brain Research, raising questions about the accountability of people going through extreme emotions.

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These Violent Delights Don’t Have Violent Ends: Study Finds No link Between Violent Video Games And Teen Aggression

GettyImages-180968005.jpgBy Matthew Warren

Claims that violent video games lead to aggression have been around since the days of Space Invaders. When young people are exposed to violent media, the theory goes, their aggressive thoughts become more prominent, leading them to commit acts of violence. But while several studies have found results that seem to back up this idea, the evidence is far from unequivocal.

Now a study published in Royal Society Open Science has failed to find any association between the time spent playing violent video games and aggressive behaviour, adding to a growing body of literature that suggests that such a link has been overstated – or may not exist at all.

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Are Criminal Profilers “Any Better Than A Bartender?” Not Necessarily, Suggests Review Of 40 Years Of Relevant Research

GettyImages-136503301.jpgBy guest blogger Tomasz Witkowski

The profession of “criminal profiler” is one shrouded in secrecy, even giving off a hint of danger. Yet when the American psychiatrist James A. Brussel began profiling a particular suspect in the 1950s, law enforcement officers were not entirely inclined to trust him. However, it turned out Brussel accurately defined the suspect’s height, clothing and even religion. This spectacular success was the beginning of the profession of the profiler. The FBI formed its Behavioral Science Unit in 1974 to study serial predators. Since then, the art and craft of criminal profiling have become the subject of numerous books, TV shows and iconic films such as The Silence of the Lambs. Criminal profilers are not, however, just characters created to make interesting films and books – in the real world the accuracy of their expert opinions is often key to protecting the safety and lives of others.

Can we say, after the passage of 40 years since the job of offender profiling (OP) was established, that this profession is a craft worthy of trust, one whose practitioners make use of tried and tested tools, or rather would it be more accurate to describe it as an art-form grounded in intuition that supplies us with foggy, uncertain predictions? Answers to these questions are given by Bryanna Fox from the University of South Florida and David P. Farrington from the University of Cambridge in the December edition of Psychological Bulletin, where they present a systematic review and meta-analysis of 426 publications on OP from 1976 through 2016. 

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Resolving “He said/She said” – Researchers outline a method for verifying the accuracy of eye-witness memories

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The findings could have “far-reaching significance” in legal contexts, the researchers said. (Photo by Mario Tama/Getty Images)

By Emma Young

One eyewitness to a robbery reports that the culprit was a male in his 40s with brown hair, wearing a light-coloured T-shirt. Another describes a blond man in his early 30s wearing a denim shirt. If you’re a police officer investigating the crime, whose memory do you trust? 

Identifying which of two apparently credible but conflicting eye-witness statements to trust is a big problem for law enforcement agencies (as is deciding, in the case of a witness who has no incentive to lie, which among their memories are accurate). Now a new paper, reported in the Journal of Experimental Psychology, provides initial evidence for a new, objectively verifiable method for doing this. This work has, as the researchers write, “potentially far-reaching significance, not the least in the legal context.” 

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Amsterdam coffee-shop study explores the effects of cannabis on eye-witness memory

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Cannabis intoxication strengthened the correlation between eye-witnesses’ memory confidence and accuracy

By Christian Jarrett

The fallibility of eye-witness memory has been well-documented by psychologists, including how alcohol intoxication undermines witness accuracy still further. In fact, psychological research into the foibles of human memory and the implications this has for legal proceedings is arguably one of the best examples of the discipline making a practical contribution to everyday life.

And yet, as Annelies Vredeveldt at VU University Amsterdam and her team explain in their new paper in Applied Cognitive Psychology, there is a striking gap in the literature: “despite the frequency with which people use cannabis, there is almost no research examining its effects on eye-witness memory.”

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Research into the mental health of prisoners, digested

GettyImages-504701778.jpgBy Christian Jarrett

Around the world, more people than ever are locked up in prisons – estimated to be in excess of 11 million people, up by almost 20 per cent since the turn of the millennium (pdf). According to a recent House of Commons Briefing Paper the rate of increase is even higher than this in the UK where prison populations are at a record high. Many of these incarcerated individuals have intensifying mental health needs – for instance, the same briefing paper reports that UK rates of self-harm in prisoners were 25 per cent higher in 2015 than in 2014. Ahead of this week’s meeting of the All Party Parliamentary Group for Psychology on the topic of Mental Health in the Criminal Justice System, here we provide a digest of research into the mental health of prisoners.

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New literature review warns that current sexual assault interventions might actually increase offending among high-risk men

GettyImages-178019463.jpgBy Alex Fradera

Psychology can help people one person at a time, but it also holds the promise of changing society at a mass scale, through campaigns to change attitudes and behaviour. One such endeavour is the development of programmes to reduce the rates of sexual assault of women on university campuses. But in a literature review in Aggression and Violent Behavior, researchers from the University of California make the case that such programmes may not just be ineffective, but counterproductive.

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Can a reasoning test predict who will make a good detective?

GettyImages-118096569.jpgBy Alex Fradera

Although criminal investigation has been transformed through technological developments in DNA, phone tracking, and online data, the way a detective works through a crime has remained much the same. The first suspect is often the true perpetrator, but not always, and snowballing biases continue to lead to miscarriages of justice. Proficient detectives need the ability to generate and evaluate different explanations and keep an open mind. New research in the Journal of Police and Criminal Psychology investigates whether it’s possible to use established tests of reasoning ability to identify who has the skills necessary for thinking this way.

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Psychologists clash over how easy it is to implant false memories of committing a crime

By guest blogger Simon Oxenham

Historically, the kind of false memories induced in volunteers by psychologists have been relatively mundane. For example, a seminal study used leading questions and the encouragement to confabulate, to apparently implant in participants the memory of getting lost in a shopping mall as a child. This reliance on mundane false memories has been problematic for experts who believe that false memories have critical real world consequence, from criminal trials involving false murder confessions, to memories of child abuse “recovered” during therapy using controversial techniques.

The discrepancy between psychologists’ lab results and their real world claims vanished abruptly in 2015 when Julia Shaw (based then at the University of Bedfordshire) and Stephen Porter (University of British Columbia) shocked the memory research community with their staggering finding that, over several interview sessions, and by using false accounts purportedly from the participants’ own caregivers, they had successfully implanted false memories of having committed a crime as a teenager in 70 per cent of their participants, ranging from theft to assault with a weapon. But now other experts have raised doubts about these claims.

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