Aren’t all dogs cute all the time, regardless of their age? While we would like to believe that, the truth, unfortunately, is not that universal.

In a paper published this month in “Anthrozoos: A Multidisciplinary Journal of the Interactions of People and Animals,” lead researcher Clive Wynne, professor of psychology and director of Arizona State University's Canine Science Collaboratory, conducted an experiment to determine at which age human beings find dogs the cutest.

For this experiment, Wynne chose 51 participants and photos of three breeds of dogs — Jack Russell terriers, cane corsos, and white shepherds — at different ages.

All the participants were asked to rate the photos out of 10, depending on how adorable they found them. After the results were tallied, it was found that a majority of people found dogs the cutest when they were eight-weeks-old.

"Around seven or eight weeks of age, just as their mother is getting sick of them and is going to kick them out of the den and they're going to have to make their own way in life, at that age, that is exactly when they are most attractive to human beings," Wynne said.

The exact reason behind people choosing the specific age confounded the researchers. According to Wynne, there could be multiple factors which led to the outcome.

"It came out exactly as I'd hoped it would — that there is indeed an optimal age of maximum cuteness, and that age does line up pretty closely with the age at which mothers wean their pups," Wynne said.

He further added: "This could be a signal coming through to us of how dogs have evolved to rely on human care. This could be dogs showing us how the bond between human and dog is not just something that we find immensely satisfying in our lives. ... But for them, it's the absolute bedrock of their existence. That being able to connect with us, to find an emotional hook with us is what actually makes their lives possible."

The study also revealed that humans tend to find dogs least cute immediately after their birth. The appeal of dogs peaked as they neared 10 weeks and then it began to subside before leveling out.

The results were: Cane corsos’ peak of attractiveness appeared to be at 6.3 weeks of age; people found Jack Russell terriers the cutest at 7.7 weeks of age; white shepherds looked most adorable at the age of 8.3 weeks.

Dogs Wynne chose fifty one participants and photos of three breeds of dogs - Jack Russell terriers, cane corsos and white shepherds – at different ages for the experiment. In this photo, Marshawn (R) and Maleek, foster children of Stephen McCall, hug a new puppy in the Crown Heights neighborhood of Brooklyn in New York City, June 10, 2003. Photo: Getty Images/ Chris Hondros

However, Wynne pointed out that the results by no means suggest that people’s love for their pets fade when their dogs start getting older.

"[The study] doesn't mean to say that we stop loving our dogs past [eight weeks]," he said. "The eight-week point is just the point where the hook is biggest, the ability of the animal to grab our interest is strongest. But, having grabbed our interest, we continue to love them all their lives."

Although humans tend to have a variety of animals as pets, the bond forged between a man and a dog is “something rather special,” Wynne said, adding that "dogs have a very open-ended social program. That they are ready and willing to make friends with anybody."

Despite promising results, Wynne’s experiment had one big limitation, which he plans to overcome in his next phase of the cuteness determining program.

He said that next time he will be using videos instead of still photos. The rest of the experiment will remain the same. This change will let researchers determine if there was anything in the movement of the puppies that attracted dog lovers, enough to affect the results.