Oncology has a reputation as one of the most rigorous areas of medicine. It runs on biomarkers, trial data, and treatment algorithms: an environment built to make decisions as rational as possible. Yet, the decisions themselves are still made by HCPs, and HCPs – even Oncologists – are shaped by emotion, mental shortcuts, and unconscious bias. Why? Cancer is part of the answer. For patients it carries fear, uncertainty, and loss, as well as resilience and hope. For physicians, life and death is in their hands. They work under pressure, fatigue, and emotional weight, even when they describe themselves as purely data-driven. At the centre of oncology is not only science but human decision-making under cognitive and emotional load. What We’ve Learned from 100s of Oncology Research Studies To explore some of the common psychological factors that come up in cancer research, we conducted a retrospective analysis of over 100 oncology projects where behavioural science was used, and analysed which psychological biases, heuristics, and non-conscious factors came up most frequently. Working Under Huge Mental Load Firstly, across over 100 Oncology studies, one finding that regularly stands out is the huge mental load and constant innovative change that doctors work under and around. From this environment, physicians find themselves in a situation of what psychologists term ‘high cognitive load’. Cognitive Load describes how mental energy is finite, and when depleted by time pressure, complexity, or emotional strain, HCPs lean less on analysis and more on intuition and habit. Both clinicians and patients exist in complex, pressurised environments. Clinicians track tumour classifications, biomarkers, treatment sequencing, prolific levels of innovation, and guidelines that keep shifting. Patients face a diagnosis, a prognosis, and an unfamiliar system, often in the same moment. In oncology, clinicians fall back on familiar treatment pathways and patients struggle to process their options, particularly at diagnosis when everything arrives at once. This is a matter of capacity, not of care or competence. The Implication? -Make things more accessible: How information is presented either adds to that load or relieves it. Reducing unnecessary detail, breaking content into structured chunks, using visuals, and keeping language readable all lower the cost of taking something in. Small changes in presentation produce measurable differences in comprehension, and in the decisions that follow. -Help doctors feel like heroes, not overwhelmed civilians: help clinicians feel confident, effective, and able to succeed. Communications that reinforce mastery, provide reassurance, reduce uncertainty, and show how a treatment helps doctors achieve the outcomes they want for patients will often travel further than data alone. At the same time, patients need hope, agency, and a sense of progress through an often overwhelming journey. The question is not only “How can we make this easier to understand?” but also “How can we help HCPs feel capable and driven to act?” Logistical Friction: The Gap Between Deciding and Doing Secondly, cognitive overload has a practical counterpart: Logistical Friction, the extra steps, delays, and costs that make action harder. In oncology, friction runs the length of the journey, from referrals and diagnostic tests to insurance approvals, travel to treatment centres, and ongoing monitoring. Each obstacle draws on the same limited reserves as the decision itself – just imagine having to do 12 metres of paperwork per patient (see image). The implication? The more friction a pathway contains, the more likely a step is to be delayed or dropped. What gets recorded as non-compliance is often effort that exceeded what someone could spare. -Remove the hassle from making the right decisions: removing friction through clearer pathways and better support is not only an operational fix; it changes behaviour. Ambiguity Aversion and Optimism Bias: The Same Uncertainty, Opposite Responses Finally, when capacity runs short, clinicians and patients reach for different shortcuts, and they pull in opposite directions. Clinicians often lean toward the known. Ambiguity Aversion, the tendency to prefer familiar outcomes over uncertain ones even when the uncertain option may be better, pushes decisions toward established treatments and away from newer ones. In a high-stakes setting this reads as protective rather than irrational: the familiar choice lowers perceived risk, even at the cost of potential upside. Patients tend to lean the other way. Optimism Bias, the tendency to expect positive outcomes, appears more often on their side. It supports coping, resilience, and engagement. It can also lead patients to underestimate risk or postpone decisions in earlier stages – or downplay the need for adjuvant therapy later in the treatment journey. The same uncertainty that makes clinicians cautious can make patients hopeful, and each response carries its own cost: caution can limit innovation, optimism can delay action. The implications? For a new treatment, this means data, education and information – such as patient leaflets or data-filled congress presentations – are necessary but not sufficient. -Reduce uncertainty for HCPs: showing real-world use, drawing comparisons to familiar therapies, framing outcomes in terms of predictability and confidence; following up with doctors to support them to build confidence. -Help patients hold onto hope: using a tone of voice which holds hope and timely action together rather than as a trade-off; and ensure patient support services are there every step of the way with the patient. None of this weakens the science. Decisions in oncology are made by HCPs who are emotionally invested, cognitively stretched, and working through uncertainty. Communications, pathways, and interventions that account for how those decisions feel, rather than how they should look on paper, are the ones that improve outcomes. Ultimately, behavioural science makes the overlooked part of a decision visible enough to design around. Work with HRW’s Oncology Team, HRW OR:BIT We apply behavioural science to the decisions clinicians and patients make in oncology, from adoption and communications to pathway and patient-support design. If you want to understand the pressures shaping decisions in your therapy area, and design around them, get in touch with HRW OR:BIT at HRW-ORBIT@hrwhealthcare.com By Oliver Daysmith, Katy Irving, and Victoria Kaulback Apply Now!