Many people spend a long time thinking about body size when choosing a breed. In a Yorkshire Terrier, size affects food intake, exercise ability, and even how hard it is to play with the dog.
But body size may also influence intelligence in some ways. According to research published on the site Dognition and organized by researchers from the University of Arizona, 7,000 purebred dogs from 74 breeds were tested through game-like tasks. In one test, food was placed under one of two cups, and after 60 to 150 seconds the dog had to remember which cup held the reward. The purpose was to test memory, and the reported result suggested that larger dogs generally remembered the process better than smaller dogs.

As body size increases, the brain is generally larger, with more nerve cells and connections. That may help explain why large breeds sometimes show stronger short-term memory and self-control and therefore are often more suitable for working roles that involve complicated tasks.

Even so, that does not absolutely mean small dogs are stupid. On the contrary, some research suggests that small dogs can show stronger social intelligence. When carrying out certain owner commands, they may perform very well because they rely more on social reasoning and sensitivity to the person.
Help the Yorkshire Terrier Start Well
People often judge a Yorkshire Terrier's intelligence by how it reacts to things and how quickly it learns, but external factors also matter, and the owner's time and energy are especially important. In many ways, training an excellent Yorkshire Terrier is similar to raising a well-guided child. Good learning ability begins with good habits and a good learning environment. So the owner should correct bad habits early, such as scavenging for food or tearing things apart.

Although some trainers believe purebred dogs may have certain natural advantages for highly specialized training, that is not the most important point for ordinary owners. Mixed-breed and local dogs can also be very smart.
Small dogs may not have the same natural cognitive advantages as some large breeds, but through repeated training they can still make up for it. The owner's attitude has a huge influence on the learning results of a Yorkshire Terrier.
So when training a smart and capable Yorkie, it is useful to focus on teamwork and coordination. Activities such as jogging together or playing agility-style games help develop physical coordination and can also support mental development. More importantly, this kind of interactive learning strengthens the bond between pet and owner.
Finally, reward the good and correct the bad. This is a universal rule in Yorkshire Terrier training. When the dog performs a command well, it should immediately receive verbal praise or a treat. Punishment, however, should avoid direct harshness. Small dogs often react more negatively to punishment than larger dogs do.
We do not train a Yorkshire Terrier to show off or gain praise from other people. We train it so that our lives and the dog's life can fit together better, and so that owner and dog can live together more happily.