News Release

Importance of neuroscientific evidence for rape trials

Peer Reviewed | Comment

Peer-Reviewed Publication

University College London

The law should take into consideration neuroscientific evidence that suggests fear and threat can cause victims to become ‘frozen’ in cases of rape or sexual assault, argue UCL experts.

In a comment article, published in Nature Human Behaviour, Professor Patrick Haggard and former UCL undergraduate, Ebani Dhawan, state that victims of sexual assault are often blamed for not fighting or fleeing their attackers.

Thirty per cent of women are thought to experience sexual assault or rape in their lifetime. And, of those who have attended an emergency clinic, 70% reported being “frozen” during the ordeal, and unable to move or cry out.

The researchers highlight court cases such as R v Lennox (2018), a case in Australia, in which the defence lawyer questions the victim as to why she froze and did not show signs of struggle, transferring the blame of the sexual assault to her.

However, the researchers argue that the victim’s immobility may be entirely involuntary – in which case blame is inappropriate. For example, research has shown that when presented with threats, the brain’s response can include blocking the neural circuits that provide voluntary control over body movement.

Many animals freeze briefly in response to mild threat, so they are poised to trigger a fight or flight reaction. But in response to immediate and severe threat, the behaviour may change to a prolonged immobility where the body becomes either completely frozen or limp. Similar processes occur in humans, and questionnaire studies have shown that sexual assault victims often report being unable to move or cry out during the assault, even when they are not physically constrained.

Arguments for the defence in rape and sexual assault cases sometimes misinterpret the absence of struggle as an indication of consent. But if the victim is involuntarily immobile, this argument is incorrect.

Corresponding author, Professor Haggard (UCL Psychology & Language Sciences), said: “The law has long recognised ‘loss of control’ defences and can accord diminished responsibility in specific situations, in which evidence shows that actions were made outside of voluntary control. This can include some medical conditions, such as sleep disorders, alongside extreme situations such as coercive control and emotional triggering.

“After reviewing neuroscientific evidence, we suggest that the same consideration should be made towards involuntary immobility during rape and sexual assault.

“We hope that this could help prevent inappropriate victim blaming and potentially draw wider societal attention to the crucial importance of active consent.”

Rape and sexual assault can have devastating impacts for both individuals and society.

In 2021-2022 the police in England and Wales recorded over 70,000 rapes. However, only 3% led to a charge.

Ebani Dhawan said: “Legal definitions of rape and sexual assault are based on the absence of consent. However, it is not unusual for victims’ reports of non-consent to be questioned in court - against un-evidenced stereotypes of how a ‘real’ victim would allegedly behave.

“For example, perpetrators may claim that they assumed the victim was consenting due to absence of any clear attempt to resist.

“We should use neuroscientific findings to prevent these myths being peddled as a defence argument for sexual violence, and to ensure justice for victims.”


Rape and sexual assault are criminal behaviours that cannot be studied directly. Animal studies can only offer a limited insight into how immobility in response to threat might affect human voluntary action control. The researchers hope their conclusions may drive future research on this neglected but important topic.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.