Abstract
In cases of child sexual abuse, children’s testimony often comprises the central evidence in
court. The reliability of children’s evidence depends on many factors, including the way that
they are questioned by an evidential interviewer. We know that open-ended questions elicit
the most accurate reports from children, and should be the predominant questioning
technique used. We also know that suggestive questioning techniques may contaminate a
child’s evidence, and should be avoided. Despite the availability of best-practice guidelines
that teach forensic interviewers about the most effective ways to interview children, some
interviewers, including those in New Zealand, continue to employ a range of risky interview
practices. Given the potential negative impact of these practices on a child’s accuracy, it is
important that the ultimate decision-makers are conscious of the impact of interviewing
methods on the reliability of children’s testimony. Despite this importance, many jurors hold
misconceptions regarding memory and are largely unaware of the influence of poor interview
techniques on children’s accounts during an evidential interview. In recognising the gap in
jurors’ knowledge, the court has implemented safeguards that are designed to help juries
reach a just verdict. One of these safeguards is specific instruction by the Judge. The
fundamental question facing the Court is whether judicial instructions are effective in aiding
jurors’ decision-making.
The overarching goal of the current thesis was to examine the effectiveness of a
judicial instruction derived from New Zealand’s Evidence Regulations 2007 (Section 49.
Warning or informing the jury about very young children’s evidence) that is currently
implemented in jury trials in New Zealand. The first aim of my research was to examine
whether the instruction did help participants to differentiate between best-practice and poor-
practice interviews conducted with a child complainant. Across three experiments, I found
that participants failed to consider the quality of the evidential interview when arriving at a
verdict, even after receiving the judicial instruction. In fact, when the instruction was
presented after the evidence (which mirrors instruction placement in the courtroom), it
appeared to induce generalised scepticism whereby jurors were less likely (Experiment 1) or
more likely (Experiment 2) to convict the defendant regardless of the quality of the interview.
In other words, the instruction was harmful –encouraging jurors to become biased in favour
of either the child or the defendant, regardless of how the evidence was elicited.
The second aim of my research was to examine whether accountability and
consequentiality impacted participants’ use of the judicial instruction. We know that
participant research often does not take into consideration of accountability and
consequentiality, which are phenomena that are more likely to occur for real jurors, but not
participants, and are important for an individual’s motivation. Understanding how
participants respond when they are more accountable for their decisions, and when they
believe their task has real-world consequences is an important step toward understanding how
individuals make these decisions in the real world. Therefore in Experiments 2 and 3, I
investigated the impact of accountability and consequentiality, and whether these factors
influenced participants’ ability to apply the information from the instruction when reaching
their verdict. Prior research has shown that when (at least some) individuals are held
accountable for the decision-making process, they have greater motivation to accurately
understand the problem at hand, and therefore, process the information more systematically.
Therefore, in Experiment 2, I investigated whether increasing accountability would motivate
participants to apply the information from the judicial instruction to their verdict. My
hypothesis was not supported; despite increasing accountability for their decisions,
participants still did not appear to apply the judicial instruction when reaching their verdict.
It is well recognised that there is a significant difference in the consequences of the
decisions that are reached by real jurors and participants. Real jurors, for example, are
required to make a decision regarding a real-life defendant, which may result in a monetary
award, prison sentence, or in some countries, a death sentence. Participants, on the other
hand, are required to reach a verdict that has no impact on the alleged victim or perpetrator.
This lack of consequence for participants may reduce engagement or effortful systematic
processing of the evidence, including the judicial instruction. In Experiment 3, I investigated
whether increasing consequentiality would motivate participants to apply the information
from the judicial instruction to their verdict. Regardless of whether participants believed that
their task had real-world implications, jurors still failed to apply the information from the
judicial instruction to their verdict. Taken together, my results—in conjunction with those of
other studies—suggest that the Court’s faith in judicial instructions is misplaced. The Court
should not rely on judicial instructions as a primary safeguard until there is evidence that they
are effective and not harmful. It is crucial that researchers work together with the judiciary to
develop evidence-based approaches to facilitate justice.