Behavioural ethics to uphold expert bias in courts

Behavioural ethics to uphold expert bias in courts

24 June 2020 By Naomi Neilson

Despite codes of conduct and with very little rigorous management of expert witnesses in Australian courts, expert bias is going largely unchecked. In a new paper, professors and experts analyse how the psychology of behaviour could maintain trust in the court.

According to three experts, there is a lack of empirical research to guide judges on the management of potentially biased expert evidence. The procedures that are intended to ensure impartiality of experts in Australian criminal law – like the codes of conduct – are only recent introductions and are limited in their overall applications. 

“Many of the concerns about expert witness partisanship merged with fears that ‘junk’ science was finding its way into courtrooms, presented by unscrupulous experts willing to tailor their evidence to the needs of their instruction client,” said lead author with the University of Sydney’s (USYD) Law School, Dr Jason Chin. 

Dr Chin said that despite the knowledge that expert witnesses might tailor all evidence, Australian courts refrain from demanding expert evidence be demonstrably reliable. In some cases when procedures are in place, Dr Chin added that courts tend to overlook more subtle forms of bias, such as unconscious contextual bias. 


Authors Dr Chin, UNSW associate professor Mehera San Roque and an LBB candidate at University of Queensland, Rory McFadden, proposed that courts could harness the psychology of ethical behaviour to manage experts and maintain trust in the system.  

Behavioural ethics is a relatively new field of research that studies how people behave when confronted with ethical dilemmas, according to the paper. The authors propose that courts should embrace behavioural ethics to counter expert witness bias. 

“Behavioural ethics illuminates the processes which encourage the expert witnesses to overstate their findings and downplay the limits of their expertise. It explains how they can do these things and still see themselves as upstanding actors in their field,” Dr Chin said.

The authors argue that codes should remind the expert of their duties to the court and interrupt the typical script and any favourable social comparisons that the expert might try to make, like comparing themselves to an unscrupulous expert. The codes should also make clear that the expert is solely responsible for their own opinion. 

“There is a pervasive court culture [in common law jurisdictions] that tolerates ‘experts’ overstating their claims and does not effectively enforce codes of conduct,” Dr Chin said.


In Australian courts, the trend has been to take all codes of conduct less seriously and, to date, the authors are aware of one decision that excluded experts failing to follow a code of conduct. The authors concluded that, despite its past failings, expert witnesses procedure is a key tool for tackling expert witness bias. 

“When designed with reference to effective scientific procedural safeguards, and enthusiastically enforced by the courts, it may provide serious benefit,” Dr Chin said.

Behavioural ethics to uphold expert bias in courts
Intro image
lawyersweekly logo
The Women in Law Awards is the benchmark for excellence, recognising the empowering women influencing the Australian legal profession, celebrating the female leaders, role models and future champions of the industry. Register for the waitlist today for the opportunity to attend this remarkable awards ceremony and network with top legal professionals and fellow peers.