The power of scent – How smell impacts human behaviour in public washrooms

Customers don’t want to just buy a great product or service, they want the entire experience to be enjoyable. From retail to restaurants and hotels, ensuring that customers have the best end-to-end experience possible can drastically increase loyalty and willingness to return. To get this right, it’s important to make sure every detail is considered – and that includes the washroom; its hygiene elements and its smell.

Why? Human experiences are cross-modal, made up of simultaneous inputs from two or more of the senses. The greater the number of senses activated in an experience, the more memorable it becomes. However, no other sense is linked so closely to memory and emotion as the olfactory sense. Our sense of smell is so discriminating that the olfactory system has been found to have around 1,000 genes that encode distinct scents, whereas vision, for instance, has only four.

For the vast majority (76%), an unpleasant smelling washroom triggers feelings of disgust, but we should also consider what affect bad washroom smells and cross modal experiences have on the reactions, memories and behaviours outside their conscious control.

The physiological impact of scent in public washrooms: An experiment

The physiological impact of public washroom hygiene looked at the extent to which different public washroom elements impacted people’s behaviours on an unconscious level. 48 participants were given a task to complete in either a bad-smelling or a pleasant-smelling washroom while their Galvanic Skin Response (GSR) and eye tracking was monitored. The purpose was to gain an understanding of the emotional impact (what they were feeling) and what they were looking at.

The power of scent and the unconscious mind: The results

Previous Initial research has shown us that consciously, bad smells in the washroom are strongly associated with uncleanliness (79%), poor hygiene (75%) and bacteria (60%). But this new research show us that bad smells also create physiological reactions that we are not aware of, driving a host of unconscious behaviours and emotions.

The research found that a bad smelling washroom experience resulted in a 40% increase in emotional impact compared to the same experience with a pleasant smell. Additionally, a bad smell amplified the physiological reactions to visual signs of poor hygiene, with people having a 39% increase in emotional impact when they encountered an overflowing Feminine Hygiene Unit (FHU), for instance, compared to a clean cubicle and a 28% higher emotional impact when they encountered paper on the floor and the toilet seat up. This demonstrates that when faced with the same washroom environment, levels of disgust towards bad hygiene are more likely to be amplified by a bad smelling washroom than one that smells pleasant.

Furthermore, eye tracking showed that 91% of people looked around to detect the source of poor hygiene when they encountered a bad smell, which allows other elements of the washroom to be questioned and criticised. From a physiological perspective, this is fascinating – as it suggests that smell could unconsciously have an impact on people’s visual attention to elements that invite disease-avoidant behaviours, such as handwashing.

The “peak-end” rule and the impact on washroom psyche

According to the “peak-end rule”, humans largely judge an experience on how they felt at its peak (i.e. its most intense point) and at its end. Businesses looking to improve their customer experience should look to what their customers tend to do at the end of their visit to their establishment. If an unpleasant washroom experience is the most salient, or final, part of a person’s experience, it can mean the difference between a positive memory and a negative one overall, regardless of how good the rest of the experience was. Even if it occurs at an unconscious level, this physiological impact could leave a lasting impression and potentially affect future purchasing behaviour, brand loyalty and the propensity to return.

Unconscious yet undeniable: The power of scent and human behaviour

For an area of a business that traditionally sees less investment than other customer-facing areas, these findings can be a revelation. Using a public washroom is an emotionally-charged experience. However, bad smells elicit a stronger physiological reaction and if a cubicle is dirty, a bad smelling washroom is likely to amplify this response. The link between smell and emotion is so significant, that the association between a malodorous washroom and the establishment it’s attached to, can become inextricably linked in the minds and memories of customers.

Bad washroom odours can occur for a variety of reasons, such as bacteria build-up in urinals and toilets as well as lack of air ventilation. Good air care solutions can remove bad smells by filtering, cleaning and freshening the air. While modern air care methods are not a staple within all organisations, the need for effective washroom odour control to avoid the impact of unconscious reactions to unpleasant washroom experiences shouldn’t be ignored.

To understand the deep connection between scent and the unconscious mind, download the whitepaper: Unconscious yet undeniable: The power of scent and human behaviour.