A new study published by researchers at the Universidade do Porto in Portugal suggests that using harsh punishments with a dog, or even yelling at them could cause long term mental and physical health problems, significantly reducing their quality of life. This study backs up previous findings which indicate that using negative reinforcement to train a dog is not healthy, and doesn’t even work either.
This new research suggests that negative reinforcement training also causes health problems because stressful postures and high cortisol levels take a severe toll on the body after an extended period of time.
According to the study:
“Our results show that companion dogs trained using aversive-based methods experienced poorer welfare as compared to companion dogs trained using reward-based methods, at both the short- and the long-term level. Specifically, dogs attending schools using aversive-based methods displayed more stress-related behaviors and body postures during training, higher elevations in cortisol levels after training, and were more ‘pessimistic’ in a cognitive bias task.”
In the study, the researchers recruited dogs from different training schools near the University. Some of the dogs came from schools that used reward-based training, while others used negative reinforcement training like yelling and leash jerking. The researchers recorded each set of dogs during their training sessions and took saliva samples to determine their stress levels. They found that dogs who were subjected to negative reinforcement showed higher cortisol levels and more stress-related behaviors, which are known to cause health problems.
The dogs were then studied over the next month to determine the long term effects of the training. In tests a month after the initial training sessions, the dogs who were trained with rewards were also better at completing tasks and more trusting of commands from humans.