A disgusting thought

We got talking about disgust over lunch the other day. Not because of the food (which was lovely), but because a friend had started a […]

We got talking about disgust over lunch the other day. Not because of the food (which was lovely), but because a friend had started a piece of work on the role of emotion in conflict resolution, and the particularly deep role that disgust can play in it.

Disgust is one of our most basic emotions and evolved to help us pass our genes on to the next generation (helping us avoid things that might cause disease, or practices that were evolutionarily disadvantageous, like incest).   Lodged in the older, reptilian part of our brain, disgust provokes strong responses, which, while difficult to alter, can be a key driver of behaviour change.

Many of the darkest moments in human history have played on this, including the genocide in Rwanda in 1994.  Hutu killers described their victims as ‘cockroaches’, and some exiled Hutus still use the term to describe Tutsis.  Disgust was also played on by Nazis in anti-Semitic propaganda.   Children in a playground will describe someone they don’t like as ‘stinking’, and David Cameron’s description of this summer’s UK looters as ‘disgusting’ played to deep receptors in people’s (voters’) minds.

Watching Sean Penn in Milk again on television over the weekend was a reminder of how recently it was acceptable for elected representatives to describe homosexuality as ‘disgusting’.  The debates in the UK Parliament in the 1960s over legalisation are littered with references to ‘unnatural’ and ‘degrading’.  Equally, it’s possible to see how quickly (in evolutionary terms) society can evolve and change what people think of as disgusting.  Rational argument about what is and isn’t socially acceptable to say and do can, over time, change the way we react.  That’s especially true of those ‘disgust’ areas that aren’t linked directly to universal, life-threatening issues; so viewing homosexuality as ‘disgusting’ is easier to reverse than viewing rotting meat as such.

Disgust can be used to good effect too.  Professor Val Curtis Director of the Hygiene Centre at the London School of Hygiene and Tropical Medicine is a world expert on the evolution of human behaviour, the role of disgust and its relationship to hygiene and morality.  She took part in a debate on the BBC a couple of weeks ago (‘Moral Disgust’ on Radio 4) in which she argued that because it’s such a powerful instinct and so closely linked to self-preservation, disgust can be a great motivator in promoting good hygiene practice.

We’re working with Val once again for Global Handwashing Day*, part of an on-going campaign to encourage handwashing with soap.  Every 15 seconds a child dies from diarrhoeal disease, the second most common cause of death in children under five in the world.  Something as simple as handwashing with soap (and the vast majority of these children already have access to soap and water) could halve this number.  As such, it is a key element in the fight to reduce child mortality (Millennium Development Goal 4).

Unilever’s Lifebuoy brand – the world’s biggest health soap brand and a co-founder of Global Handwashing Day – invests in many programmes to promote handwashing with soap (which has the twin and therefore sustainable benefits of saving lives and selling soap).  A number of these programmes use our disgust reactions through a special glo-germ demonstrator.  This simple piece of kit shows people the invisible and odourless germs left on their hand after washing with water alone.  This taps into deeper emotional responses – by making the invisible visible – and helps a new, potentially life-saving habit take root.

Disgust has been used in communications for centuries, often for bad.  It can be a force for good though and it’s worth considering that (as well as other emotional reactions) when trying to change behaviours.  Thanks for reading.  I hope I haven’t put you off your lunch.  And please feel free to add your thoughts – especially if you’re a social anthropologist who knows a whole lot more about this than I do.


* Global Handwashing Day is on 15th October every year.  Make a pledge on their Facebook page, and
Lifebuoy and its partners will bring hygiene education to one more child for every pledge received.