Like Humans, Dogs Have Personalities That Change Over Time, Study Finds

Dog owners will tell you that their canine companions have personalities, and a new study from Michigan State University says those personalities are likely to change over time.

The study, published in the Journal of Research in Personality, found that dogs’ personality change, much like humans.

“When humans go through big changes in life, their personality traits can change,” the lead author, professor William Chopik, said in a university release. “We found that this also happens with dogs ― and to a surprisingly large degree.”

“We expected the dogs’ personalities to be fairly stable because they don’t have wild lifestyle changes humans do, but they actually change a lot,” he added. “We uncovered similarities to their owners, the optimal time for training and even a time in their lives that they can get more aggressive toward other animals.”

The study was one of the first to look at changes in dogs’ personalities. It was also the largest, with Chopik collecting surveys from owners of more than 1,600 dogs. Participants in the study evaluated their dogs and answered questions about their own personalities. The dogs included 50 breeds and ranged in age from a few weeks to 15 years old.

“We found correlations in three main areas: age and personality, in human-to-dog personality similarities and in the influence a dog’s personality has on the quality of its relationship with its owner,” Chopik said. “Older dogs are much harder to train; we found that the ‘sweet spot’ for teaching a dog obedience is around the age of 6, when it outgrows its excitable puppy stage but before it’s too set in its ways.”

Chopik said the notion that dogs resemble their owners was also supported by the study. For example, extroverted people rated their dogs as more excitable and active. People who rated themselves as agreeable described their dogs as less fearful and aggressive.

Chopik said he plans to study how environment can affect dogs’ behavior.

“Now that we know dogs’ personalities can change, next we want to make strong connection to understand why dogs act – and change – the way they do,” Chopik said.