section_path: Behavior/Intelligence
section_name: Intelligence
paragraph_text: Intelligence
  
  Researchers have tested dogs' ability to perceive information, retain it as knowledge, and apply it to solve problems. Studies of two dogs suggest that dogs can learn by inference. A study with Rico, a Border Collie, showed that he knew the labels of over 200 different items. He inferred the names of novel things by exclusion learning and correctly retrieved those new items after four weeks of the initial exposure. A study of another Border Collie, Chaser, documented that he had learned the names and could associate them by verbal command with over 1,000 words.
  
  One study of canine cognitive abilities found that dogs' capabilities are similar to those of horses, chimpanzees, or cats. One study of 18 household dogs found that the dogs could not distinguish food bowls at specific locations without distinguishing cues; the study stated that this indicates a lack of spatial memory. A study stated that dogs have a visual sense for number. The dogs showed a ratio-dependent activation both for numerical values from 1–3 to larger than four.
  
  Dogs demonstrate a theory of mind by engaging in deception. Another experimental study showed evidence that Australian dingos can outperform domestic dogs in non-social problem-solving, indicating that domestic dogs may have lost much of their original problem-solving abilities once they joined humans. Another study showed that after undergoing training to solve a simple manipulation task, dogs faced with an unsolvable version of the same problem look at humans, while socialized wolves do not.