Every dog owner has run this errand: the beloved toy has finally been disemboweled, so you go hunting for a replacement that looks exactly the same. Same color, same shape, same cartoon face. And sometimes the dog sniffs the perfect visual replica and walks away unimpressed.
A study from the Family Dog Project at Eötvös Loránd University in Budapest, published in Scientific Reports, offers an explanation: you were matching the wrong feature. When dogs decide what an object is, texture appears to outrank shape.
The experiment: one name, three shapes, three textures
Humans are famously shape-first. In a classic 1988 developmental-psychology finding, when children learn a name for a new object, they extend that name to other objects with the same shape, not the same size or surface. It is why a toddler who learns “cat” on a tabby can label a hairless Sphynx correctly on sight. Researchers call this the shape bias, and it quietly structures how we assume everyone, including our dogs, sorts the world.
The Budapest team, led by Claudia Fugazza, put that assumption to the test on 25 dogs. Each dog learned to fetch one specific target object, nicknamed “Dax,” out of a pile of distractors. The objects were built to isolate the variables: foam cores shaped as cylinders, triangles, or rectangles, wrapped in one of three surfaces, velcro, duct tape, or bare foam. Color, weight, and volume were held identical, so the only things that could distinguish “Dax” were its shape and its feel.
Then came the trick. In the test trials, each dog chose between two objects: one matching Dax’s shape but not its texture, and one matching its texture but not its shape.
Eyes first, mouth decides
The dogs did something revealingly two-staged. They usually approached the shape-match first, suggesting their eyes did the initial screening the same way ours do. But approach is not identification. Once the dogs made contact and could feel the objects, they overwhelmingly picked up and retrieved the texture-match as “Dax.”
Fugazza’s team read this as a division of labor between the senses: vision for the first pass at a distance, touch and mouth-feel for the final call. If the researchers had scored only which object dogs walked toward, they would have concluded dogs share our shape bias. Scoring what dogs actually retrieved flipped the answer. A dog’s shape bias, the team concluded, shows up only when vision is the sole sense available; give them full sensory access and texture wins.
That fits how dogs live in their bodies. So much of a dog’s object-world runs through the mouth, and a toy’s identity may be less “the blue bone-shaped one” and more “the one that gives and crinkles exactly like this between my teeth.”
The practical bit: replace by feel
Which brings us back to the pet-store errand. When a favorite toy dies, stop matching the picture and start matching the material. Rubber density, plush softness, the crackle of an internal crinkle layer, the give of the squeaker, the nubbly versus smooth surface, these are the features your dog will recognize as the same toy reborn. A replacement that looks wrong but feels identical is far closer to the original, from your dog’s perspective, than a perfect visual clone in a different material. If you have ever wondered why the identical-looking replacement got rejected, check the material list first.
What newer research adds
The same Budapest lab has kept pulling on this thread. Follow-up work published in Scientific Reports in 2025 dug into the rare dogs who learn verbal labels for many toys, the so-called gifted word learners, asking what cognitive traits set them apart, and related research from the group has shown some dogs can even extend labels based on an object’s function, what it is for, not just its physical features. The picture emerging across these studies is consistent and a little humbling: dogs are genuinely skilled at categorizing the things in their world. They just file them under different features than we do, and the filing system smells and feels more than it looks.
References
- Shape and texture biases in dogs’ generalization of trained objects (Scientific Reports)
- Dogs prefer texture over shape when identifying objects (Phys.org)
- The importance of shape in early lexical learning (Landau, Smith & Jones, Cognitive Development)
- What makes a dog a label-learner: individual cognitive differences underlying label-learning abilities in domestic dogs (Scientific Reports)
