Mental Models of the Underworld

This is the first in a series of posts inspired by the Bryan Lovell Meeting at the Geological Society, 24th to 25th Nov 2016. More details here

At the end of two days talking about watery hazards such as flooding, drought, landslips and sinkholes came a session focused upon communication skills to explain those risks to the people who are affected by them. But there's a catch: it's not enough just to use what you think are simplified words in place of your usual engineering or geological jargon. First, you need to establish whether you have any concepts in common to which you can refer!

Hazel Gibson from Plymouth University presented a fascinating piece of research based on the idea of "mental models"*, which found that there is actually very little common ground between the expert and the public when it comes to understanding the ground beneath our feet. Concepts of above-ground features such as rivers, mountains or different types of rock were shared (although understandably the expert's concept was more detailed), but as soon as you leave the realm of what most ordinary humans experience, it becomes a lot less understood.
For example, most people did not share the geologist's concept of void space, as evidenced by the response to the question "can water flow through solid rock?" Many people answered "no" or "not sure" (and apparently wrote reams of responses to the question about exactly what might be meant by "solid rock").

If you have no concept of permeable and less permeable rocks, where then does the water go? For many people, the answer is obvious: water must make a channel for itself and flow through it  - just like a river, but underground. After all, we've all seen photos of caverns with stalactites and water running through them, and where I grew up, pretty much everyone had been down the Blue John Mine, Speedwell Cavern (which even has a boat trip in the cave to help you) or similar places in the Peak District. 

This means that when we want to talk about springs, groundwater or the water table rising and falling**, we cause confusion we may not have expected. A similar problem occurred when consulting on a new carbon capture and storage project in Switzerland. Scientists couldn't work out why they were getting such a vehement rejection from local people to the very idea of trialling the project, but it turned out that a single word, "bubble", caused all the problems. They had chosen "bubble" to explain how the gas would be stored deep underground in the rock. But they had not considered that to most people, the key feature of a bubble is its fragility: bubbles go "pop", which sounds like a very dangerous thing to happen if your house is sitting on top of it.  

So what can we learn to communicate better, whether about flooding or fracking?

1. Don't assume that everyone shares the same concepts of how the world works. Instead, this research demonstrates that mental models are a very useful way to investigate how your audience might think about the issues you want to explain, and hence what concepts you can hang your argument on.
2. Always move from the familiar to the more difficult. In the case of ground problems, this means we need to start above ground with photos before moving onto the maps and cross-sections, because there is much more common understanding of features above ground. Don't lose people in your first few words!
3. Be prepared for unexpected interpretations (see recommendation 1!) 

*The research method included a combination of semi-structured interviews to explore what concepts people held about the ground, including sketching or modelling them, followed by a questionnaire given to a larger number of people to test whether the concepts expressed were held widely within the community. The research was conducted in three villages in the South West, some of which had a history of mining. 

** Another great example of how our mental models shapes how we perceive the world and what associations we make. Geologists usually talk about groundwater level going up or down, as if we were talking about a 2D cross section like we usually draw it. Apart from the (rare) 2D situation where rainwater infiltrates vertically downwards, this concept makes it harder for us to visualise the way that in reality, water usually flows from here to there, not vertically up and down.

For further reading:

• In Praise of Precision - Perhaps this research explains why the critical difference between an embankment and a cutting is not a concept shared by most of my non-geotechnical colleagues. If you don't really know what an embankment is made of, you won't be too concerned about whether one is naturally occurring soil in layers and the other is a melange of human-mixed soil from somewhere else.
• Presuasion by Robert Cialdini - I'm reading this book at the moment, and there are some real gems about how associations can be triggered by all sorts of unexpected things, which can help when you are trying to influence the public.
• Talking Climate - my ICE webinar (June 2016) about climate communication for engineers
• Climate Outreach - lots of excellent research about testing your message and pitching important messages using values which others can resonate with (particularly the centre-right).