When solving a problem, humans are more likely to add things in rather than take them away. This happens in any aspect of life, but it can also be true in safety management—and could be doing more harm than good. 

A crucial part of safety management is problem solving. Whether an incident investigation, risk assessment or inspection, safety personnel are looking for ways to improve the current situation. 

This is where the “addition bias” comes into play, and you likely don’t even know you’re doing it. 

What is the addition bias?

The addition bias refers to people’s default preference to add elements to solve a problem rather than take them away. 

It’s something that researcher Leidy Klotz first noticed when playing with Lego with his 2-year-old son. When faced with a lopsided bridge, Klotz turned to add another brick to the shorter column, whereas his son simply took one away from the longer side. 

Published in Nature, Klotz’ research presented participants with a series of objects, ideas, or situations to improve. The results showed “people systematically default to searching for additive transformations, and consequently overlook subtractive transformations.”

For more information: Less is more: Why our brains struggle to subtract - YouTube

For example, participants were asked to change a pattern on a grid of squares to make it symmetrical. Although removing existing squares would have done the trick, 78% chose to add new squares.

The bias may be down to our past need to accumulate more food, more firewood, more allies, and more power, accentuated by western consumerism influence to acquire rather than lose. 

How does it affect safety management? 

The addition bias was something I was first alerted to by one of our clients, a Risk & Systems Manager at a global manufacturing brand. 

When discussing configurations of safety software with his team, Nigel Graham observed a preference to add: 

“What we found was that given what is essentially a new design, there is a great tendency to add features – with associated costs. In essence, given a problem, people default to adding things in rather than taking them away. Even if subtracting something can solve the problem, there is a strong preference to add.”

In this way, addition bias can affect safety management systems by, for example:

• Adding too many new steps to an SOP following a near miss or incident 
• Introducing more and more PPE during a risk assessment
• Requesting too much information from workers on safety forms

In some cases, addition is required. But we should always consider simplification – asking “what can we remove?” demands a different mindset, looking at the challenge as a whole, which could result in much more efficient processes. 

And in turn, efficiency encourages engagement. 

Addition bias can lead to unnecessary features

The addition bias manifests in a range of ways, including something anyone involved in software would recognize as “feature bloat”. 

Feature bloat is when there are so many bells and whistles added to a solution, it can no longer perform its core purpose well. 

In reality, this can look like workers not logging incidents through the incident reporting software because the form is too complicated.

This means, when configuring the likes of safety inspection software, safety managers should resist the urge to add new checklist questions simply because the option is available. Instead, focus on what could be streamlined — are there parts of the checklist that could be consolidated? Now that you have more traceability, would one approval do the trick rather than two? 

Subsequently, keeping in mind the addition bias can help shape a well-considered program. 

Keep it simple, stupid!

Safety professionals are no strangers to removal. As visualized in the hierarchy of controls, elimination is the first and most effective hazard exposure measure.

So, to combat against the negative effects of an addition bias, similar logic can be applied to problem-solving in other areas.

The addition bias is something I’ve personally witnessed in my years of editing safety management articles. When working on improvements, passionate writers are tempted to include evermore information to get their point across, resulting in hours of extra effort. However, often, the article becomes clearer and more engaging when some original paragraphs are removed. In this example, subtraction can be a more efficient approach that achieves the same goal.

After all, as succinctly put by Antoine de Saint-Exupéry, “Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.” 

Or, in less sophisticated but perhaps more memorable terms: keep it simple, stupid!

Have you seen the addition bias in action? Will being aware of it change your approach to safety management systems?