The ‘monkey cucumber grape’ test is fun and profound too, it provides insights into the importance of fairness at work.
This research was first conducted by Frans De Waal, (it is also known as the Capuchin monkey fairness test). In the test, two monkeys perform a simple task. One monkey receives a piece of cucumber for completing the task, the other monkey receives a grape for completing the task.
The two monkeys can see each other perform the same task and see the rewards they receive.
See what happens when one monkey receives the tastier reward.
The ‘monkey cucumber grape’ test
Capuchin monkeys live in social groups in their natural environment of South America, and it is this social connectedness that is at the root of their response. Here’s more on this, from UC Berkeley.
The new finding that even monkeys reject unequal pay is very important… it suggests that this is a very deeply rooted behavior that we observe among humans.
Ernst Fehr, Swiss economist
It’s clear that Capuchin monkeys have a well tuned sense of what is fair and what is not, and that has implications for us all.
According to David Rock, unfairness at work creates a threat response that can be quite overwhelming, shutting down the ‘executive function’ of the brain and resulting in frustration and anger.
Fairness and the SCARF Model

The model is based on an ‘organizing principle’ of the brain: that we instinctively aim to minimize danger and maximize reward. If we are maximizing reward we’re engaged and actively involved. However, if we’re triggered to minimize danger (by feeling unfairly treated, for example) we develop a ‘fight, flight or freeze’ mentality.
In the model, David Rock identifies five factors that influence our behavior. These five factors are largely subconscious.
In the video above, the ‘fight’ response is triggered in the Capuchin monkey as it feels unfairly treated, it wants the grape and rejects the cucumber.
If there are raging monkeys in your team, remember the Capuchin monkey fairness test and the SCARF model. It might provide a clue to the problem!
More lighthearted and insightful videos
If you enjoy lighthearted and insightful videos, take a look at these:
- Learning to unlearn: the backwards brain bicycle
- ‘Great ideas’ from two Aussie lads
- Matt Cutts’ 30-day challenge
- Selective attention test examples
- The conference call in real life
All entertaining, all insightful!