Puss in Boots, with his enormous eyes, is one of the cutest characters in animation. Scientists have borrowed his name to describe an unusual phenomenon: dogs with big eyes are perceived by women as “adorable,” almost childlike, and that perception makes women speak to those animals in a baby‑talk style. In turn, dogs are more receptive to that kind of female communication.
The “Adorableness” of Dogs with Big Eyes
Researchers found that women, unlike men, tend to use a higher pitch when talking to dogs with large eyes. The team dubbed this the “Puss in Boots effect,” which highlights differences in how men and women perceive “adorableness.” Previous studies have shown that when communicating with infants and dogs, people tend to use a higher tone to capture attention. However, it remains unclear how that speech varies across different dog breeds.
For this study, the team enlisted 21 men and 24 women and asked them to interact with photographs of dogs from 12 different breeds. The images were manipulated so that the eyes of each dog were either 15% smaller, 15% larger, or 30% larger than normal. More than 400 people were surveyed online to assess the perceived gender, age, and “adorableness” of the dogs in the images. The results indicated that women, unlike men, spoke to dogs with larger eyes using a higher pitch.
The Limits of the “Puss in Boots Effect”
Women also rated dogs with big eyes as younger than dogs with smaller eyes. Researchers think this ties to neoteny, where animals with larger eyes are perceived as younger. One of the study’s authors, Dr. Holly Ruth‑Gatteridge, told the Daily Mail that the findings show men and women respond differently to “adorableness,” even at an unconscious level.
Men are less responsive to changes in eye size than women. The study also confirms that people are sensitive to cues of youth in animals. But the Puss in Boots effect has its limits. Co‑author Gemma Forman noted that when a dog’s eye size becomes excessively large and looks unnatural, an “Uncanny Valley” effect kicks in, making dogs seem less pleasant and more unsettling. As a result, women speak in a less exaggerated tone to dogs with overly large, striking eyes. This is especially visible in breeds like pugs or Pomeranians, which already have relatively large eyes for their head size.
Dogs Prefer Female “Baby Talk”
Another study found that dogs are more sensitive to high‑pitched female voices. Brain scans show that these pets actually listen to our conversations with them much like human infants do. Infants are highly responsive to a high, sing‑song tone called “infant‑directed speech,” which researchers argue helps brain development. Infants are exposed to that influence even in the womb, while dogs do not have the same prenatal exposure to women’s voices.
The study involved 19 dogs from eight different breeds, aged between 2 and 10 years. Researchers scanned each dog’s brain using an fMRI while playing three types of recorded speech from both men and women directed at dogs, infants, and adults. The dogs’ brains showed greater activity when listening to “baby talk,” the tone typically used for infants and pets. The animals were particularly responsive when the speaker was female.
Why Are Dogs Sensitive to “Baby Talk”?
During the brain scans, scientists found that the same areas of dogs’ brains were activated as in infants when they heard “baby talk.” Researchers offer two theories for how this sensitivity may have developed in animals: either mammals long had a universal responsiveness to high‑pitched sounds, or dogs acquired the trait during domestication.
Neuroethologist Anna Gabor and her colleagues suggest that early dogs who were more sensitive to “baby talk” may have stayed close to humans and become domesticated because they paid attention to human vocal signals. Some experimental data indicate that wolves respond better to soft speech, while dogs are more attuned to higher tones. Gabor’s team included only 19 dogs in their study and did not control for the gender of the pets’ owners, which could have influenced the types of speech the dogs were most sensitive to. Therefore, researchers say further studies are needed, since the parallels they found between how dogs and human infants respond to adult voices deserve deeper exploration. Perhaps pets can help us understand what humans were like before they began to speak.
