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What is Contrafreeloading & How Does it Affect Enrichment?

Updated: Sep 1, 2022

Today, I want you to do something different with your dogs. I want you to take a bowl of food, and I want you to take the same food placed inside a puzzle of some sort. The food puzzle could be a wrapped towel puzzle, an enrichment box, a KONG Wobbler - you name it. Place these two options in front of your dog. What option do they go for?

Many of you may be surprised to learn that your dog will often pick the latter due to a concept called contrafreeloading.

"Contrafreeloading is the behaviour seen in most animals that when an animal is offered a choice between free food or identical food that requires effort, the animal prefers the food that requires effort" (Glen Jensen, 1963).

What does this mean?

What this means is that when an animal is provided with a choice between free food and food that they have to work for, they'll often choose the option that takes a certain amount of effort.

When it comes to dogs specifically, we must remember that they have deeply sewn genetic qualities when it comes to foraging. Instinctively, a dog's senses are tuned to look for food. So much so, that the act of searching and foraging for food can be more of a thrill for your dog than the actual act of obtaining the food itself. This helps us explain why puzzle toys and activities can be so enjoyable for dogs.

Professor Robert Sapolsky's Study: Dopamine and Anticipation

One of the most interesting studies that works hand in hand with the contrafreeloading concept is Professor Robert Sapolsky's study on dopamine and anticipation. In his study, monkey's were given a light as a "signal". This was a signal that they could go ahead and press the button in front of them (pressing the button = "working for food"), and as a result they would receive food once the button was pressed.

This is a recreated chart from the Sapolsky study, which shows the dopamine levels in the brain SKYROCKETING at the signal and work, and not the reward itself.

Above: Recreated chart from the Sapolsky study, which shows the dopamine levels in the brain skyrocketing at the signal and work, and not the reward itself.

Professor Sapolsky's experiment showed us that certain animals experience more happiness searching for the reward than the reward itself, which happens through the release of dopamine (a feel-good brain chemical) when an animal begins their search for food (Shay Kelly). Contrary to popular belief, the dopamine happens through the animal's excitement over the anticipation, and not when they actually obtain the food (Shay Kelly).

What does this mean for enrichment?

Contrafreeloading and it's relationship with enrichment work hand in hand. When food is readily available, the act of food puzzles, ditching the bowl, snuffle mats or stuffable toys are enjoyable to most animals (dogs, raccoons, even CHICKENS!).

Why? Because these interactive feeding toys activate the pleasure centers in your dog's brain, leading to a happier, more stimulated animal in front of you.

Here are some photos of enrichment activities that display the contrafreeloading concept at the Toronto Zoo :

Above: All photos above are compiled from the Toronto Zoo. Click Here to learn more about what forms of enrichment they offer to animals of all different species at their location.


Like most things in life, there are exceptions to this concept. Studies found that animals must have a reliable food source available in order to witness contrafreeloading across animal species (i.e., a starving animal will not care for puzzles - they will go for the easiest food source available to them). Additionally, one species that didn't follow the same trend with contrafreeloading as the rest: Standard house cats! I'm sure this will not be a surprise to many, but when it comes to food - statistically - house cats prefer free meals. Note: While a cat may not choose a puzzle over their standard bowl of food as readily as other species, this doesn't mean that cats can't benefit from the mental stimulation or joy that can come with many enrichment activities!

An important side note is that while animals may like to work for their food, it's important that we don't make these activities too difficult or impossible. Always ensure you're modifying games and activities to set your animals up for success.

Ready to start getting your enrichment on? Read about these 5 Common Misconceptions before you start.


Want to learn more about Enrichment Basics, without having to comb through content across platforms? Take a look at our new Enrichment Guide!




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