It is a common misconception amongst laypersons encountering the law—whether through personal involvement in the legal system or through vicarious interest in a publicised case—that convincing evidence alone constitutes proof. We’ve all heard others make snap judgements about a suspect’s guilt based on an arbitrary factor, like an awkward tone or an ostensibly implausible alibi.
As demonstrated in studies validating neuroscientist Antonio Damasio’s Somatic Marker Hypothesis, human emotions were shaped to serve evolutionary functions like immediate survival, rather than the optimisation of logical deliberation. A potential threat, like a snake-shaped object in the grass, understandably results in an immediate emotional reaction, bypassing the logical functions of the brain that can take too long to process the threat. Because criminals and those with ill intent are naturally perceived as a threat, humans are generally inclined to believe that any evidence of culpability is definitive, without considering the evidence as a whole.
It is not only laypersons who are susceptible to this manner of thinking. The Full Court of the High Court of Australia unanimously overturned George Pell’s historic convictions for assault, deciding that the Victorian Court of Appeal attributed too much weight to a complainant’s compelling evidence. The High Court ruled that other evidence had not been adequately assessed.
Surprisingly, even defendants themselves are sometimes uncertain of their innocence due to factors like systemic pressure to confess. According to data tracked by the National Registry of Exonerations, around 25% of individuals later cleared by post-conviction DNA evidence in the US confessed to crimes they did not actually commit.
As a private investigator, when endeavouring to explain the mechanics of evidence to non-lawyers—whether the evidence is for legal cases or a client’s peace of mind—I emphasise three considerations that help counteract the cognitive biases described above.
Firstly, if evidence is available, it should be sought. It’s important to scour any source of information, physical evidence, or data in the fact-gathering stage of an investigation to ensure nothing is missed, especially any evidence that contradicts one’s initial findings or beliefs.
Secondly, one should seek to take a 360-degree view of any piece of evidence gathered in order to contextualise it as accurately as possible. By adopting a multi-angle view, evidence can be considered in light of the goal, the other evidence gathered, and the burden of the unknown or unknowable.
Thirdly, we err on the side of doubt. The best example of this principle is the tale of duty officer Stanislav Petrov, who saved the world from nuclear war by correctly identifying that an early-warning system was erroneous when it reported that the USSR was under attack by the US. He used the limited time that he had to consider the data before him in the abstract, whilst all around him there was agitation.
At every step, we work against the evolutionary conditioning to “go with our gut.” We can and should use our intuition, but only to interpret the evidence that we have already considered in an objective light. As Abraham Lincoln warned, “Passion has helped us; but can do so no more. It will in future be our enemy. Reason, cold, calculating, unimpassioned reason, must furnish all the materials for our future support and defence.”
We are not seeking evidence to simply support our proposition; we are seeking to uncover evidence of such weight that it will preclude a serious consideration of any thesis other than the one we have logically developed. If we can do this and self-reflexively anticipate the objections to our findings so they can be dealt with before they arise, we will come as close as possible to providing what we can properly term proof. After all, every battle is won before it is fought, to paraphrase the famous strategist Sun Tzu.
Uncovering the truth is, intellectually, often a straightforward task. I believe just about anyone has the intelligence to identify what constitutes proof. The challenge is one of emotion. Disregarding our subjective reaction to stimuli is an incredibly difficult task, as it forces us to adopt a mode of thinking in which we directly fight against our natural impulses.
