This team of Swedish scientists decided to ask whether dogs have what in the humans we often call the "Eureka Effect". It is a sudden surge of positive feeling that we get when we solve a difficult problem. According to tradition the term comes from an incident involving the Greek scientist and inventor Archimedes, who was asked to determine whether goldsmiths had adulterated what was supposed to be pure gold in the crown of Hiero II (the king of Syracuse) with some other metals. While looking at the water level rise as he immersed himself in a bath the answer to his problem came to him. Archimedes then took to the streets naked—so happy and excited by his discovery that he had forgotten to dress—all the while shouting crying "Eureka!" (from the Greek heurēka which means "I have found it"). It is this same gush of positive feeling which provides the reward that keeps us working at puzzles like crosswords, Sudoku, and many computer games involving problem-solving.

The study is a bit complicated so let me just stick to the highlights. The animals tested were 12 female beagles. There were six different tasks which the dogs could be trained to do: pressing a lever, pushing a box off of the stack, tipping over a plastic construction, pushing a ball off of a table, pressing a paddle to ring a bell, or pressing a key on a toy piano. When the dog was successful there was a sound cue such as a click or a bell followed by a reward. Each dog was trained to perform three out of the six possible tasks.

After a layoff of a week the testing began. A brand-new test environment was used. It had a starting compartment with a gate that opened to a large arena. When the gate opened the dogs gained access to a reward at the far end of the room. The experimenters were aware of research which suggests that food seems to be the most effective reward for most dogs (click here to read about that), therefore they systematically varied the nature of the rewards available to their test subjects. Dogs could receive a food reward, be rewarded by social contact with a human who would pet them, or rewarded with a chance to have social interaction and play with two other dogs. At the beginning of each test session, there were two trials where the gate was opened and the dog got to see what kind of reward he would get that day.

Next one piece of test apparatus was put in the start area. In the experimental conditions (where dogs had been trained how to operate the device which was present), what the dogs had to learn was that although each problem worked in the same way, the results were different. Now working the apparatus resulted in a sound signal and the gate swung open so that the dog could go and get her reward. In the control conditions a piece of apparatus of the dogs had not been trained on was in the start area and the dog's manipulation of it had no effect, however each dog was given rewards (sound and gate opening) with the same timing that the experimental dog in the previous session had obtained her rewards.

The most important assessments which were used involved measures of how quickly the dogs shot out of the gate to get their reward, their activity level (believe it or not researchers counted every individual paw movement) and tail wagging (they counted every tail wagging movement recorded on the video). Activity level measures excitement, while tail wagging and speed at which the dog goes for the reward are measures of how positive the dog is feeling.

The overall pattern of the results is fairly easy to describe. When the dogs correctly manipulated the apparatus and got a reward their activity level was higher, and they showed much more positive responding (such as tail wagging) then when they simply received the reward on what must have appeared to them to be a random schedule. In other words, solving the problem to get the reward made the dog feel better than simply getting the reward without any intellectual accomplishment.

Another important finding was that the degree of their positive feelings was associated with the nature of the reward whether it was earned by problem solving or simply given to them. Consistent with previous research it was once again confirmed that food seems to be the most effective reward for dogs. Thus the fastest and most positive responses were to a food reward, followed by petting and social contact from a human, with social contact and play with other dogs being the least desirable to the dogs in this study (although it was still an effective reward).

It is interesting to note that the dogs seemed to be quite happy and interested when they were brought into the testing sessions and could see that they would be interacting with a piece of apparatus that they were familiar with, and therefore found themselves facing a problem that they knew they could solve. When presented with one of the pieces of apparatus that they had not been trained on, the dogs seem to show frustration and reluctance, even though they were going to receive exactly the same number of rewards that they otherwise would have had to work for. It was their lack of control over the situation that seemed to bother them.

The experimenters are quite certain that the dogs were experiencing that "Eureka Effect". In their conclusion they report "In our study, we found behavioral differences during the actual process of understanding, providing evidence that it was success in the problem-solving that elicited a positive affective state in the experimental animals." In other words, like Archimedes, the solving of a problem gives dogs a burst of positive feeling—but unlike the Greek scholar they do not feel any when they find that they have rushed out into the world naked because they were overcome with at their accomplishment.

Stanley Coren is the author of many books including: The Wisdom of Dogs; Do Dogs Dream? Born to Bark; The Modern Dog; Why Do Dogs Have Wet Noses? The Pawprints of History; How Dogs Think; How To Speak Dog; Why We Love the Dogs We Do; What Do Dogs Know? The Intelligence of Dogs; Why Does My Dog Act That Way? Understanding Dogs for Dummies; Sleep Thieves; The Left-hander Syndrome

Copyright SC Psychological Enterprises Ltd. May not be reprinted, reposted without permission

Data From:

Ragen T. S. McGowan, Therese Rehn,Yezica Norling and Linda J. Keeling. Positive affect and learning: exploring the ‘‘Eureka Effect’’ in dogs. Animal Cognition, October 2013 (published online).