Dog intelligence is "...the resultant of the process of acquiring, storing in memory, retrieving, combining, comparing, and using in new contexts information and conceptual skills" as it applies to dogs.
Studies have shown that dogs display many behaviors associated with intelligence. They have advanced memory skills. For example, a border collie, "Chaser", learned the names of over 1,000 objects and retrieved them by verbal command. Dogs can use such memory skill to make inferences. For example, another border collie Rico, learned the labels of over 200 items and then inferred the names of novel items by exclusion. That is, he identified and retrieved those novel items immediately and also 4 weeks after the initial exposure. Dogs are able to read and react appropriately to human body language such as gesturing and pointing, and to understand human voice commands. Dogs demonstrate a theory of mind by engaging in deception.
Perception is the organization, identification, and interpretation of sensory information in order to represent and understand the environment. Perception includes the use of the senses and the selective mechanisms (attention) that influence perception. The dog's senses include vision, hearing, sense of smell, taste, touch and sensitivity to the earth's magnetic field.
- See further: Dog anatomy-senses
Dogs have often been used in studies of cognition, including research on perception, awareness, memory, and learning, notably research on classical and operant conditioning. In the course of this research, behavioral scientists have uncovered a surprising set of social-cognitive abilities in the domestic dog, abilities that are not possessed by dogs' closest canine relatives nor by other highly intelligent mammals such as great apes. Rather, these skills parallel some of the social-cognitive skills of human children. This may be an example of Convergent evolution, which happens when distantly related species independently evolve similar solutions to the same problems. For example, fish, penguins and dolphins have each separately evolved flippers as solution to the problem of moving through the water. With dogs and humans, we may see psychological convergence; that is, dogs have evolved to be cognitively more similar to humans than we are to our closest genetic relatives.:60
However, it is questionable whether the cognitive evolution of humans and animals may be called "independent," as the cognitive capacities of dogs have inevitably been shaped by millennia of contact with humans. As a result of this physical and social evolution, dogs have acquired an ability to understand and communicate with humans. Research in canine cognition is revealing the range and variability of skills such as following pointing and gaze cues, fast mapping of novel words, cognitive bias and the possibility that dogs have other emotions.
Other studies suggest that domestic dogs may have lost some of their original cognitive abilities once they joined humans. For example, one study showed compelling evidence that Dingos (Canis dingo) can outperform domestic dogs in non-social problem-solving experiment, Another study indicated that after undergoing training to solve a simple manipulation task, dogs that are faced with an insoluble version of the same problem look at the human, while socialized wolves do not. Thus, modern domestic dogs seem to use humans to solve their problems for them.
Finally, it should be noted that most modern research on dog cognition has focused on pet dogs living in human homes in developed countries. This is only a small fraction of the dog population, and dogs from other populations may show different cognitive behaviors. Breed differences among dogs indicate that genetic factors play an important role in dog intelligence, and such differences must be also taken into account in interpreting studies of cognitive capacity.
The concept of "object permanence" relates to the ability of an animal to understand that objects continue to exist even when they have moved outside of their field of perception. Developmental psychologist Jean Piaget described the development of object permanence in human infants as having six stages. This stepwise approach is sometimes used in studies of the cognitive abilities of non-human animals. There is ample evidence that dogs reach the advanced stage of 5 in which they are successful at “successive visible displacement” in which the experimenter will move the object behind multiple screens before leaving it behind the last visited location; Stage 5 object permanence is fully developed at 8-weeks-old. There is conflicting evidence whether dogs reach Stage 6 of Piaget’s object permanence development model. Dogs go through a series of stages of cognitive development. As with humans, the understanding that objects not being actively perceived still remain in existence is not present at birth. It develops as the young dog learns to interact intentionally with objects around it, at roughly 8 weeks of age.
In 2013, a study indicated that dogs appear to recognize other dogs regardless of breed, size, or shape, and distinguish them from other animals.
In 2014, a study using magnetic resonance imaging demonstrated that voice-response areas exist in the brains of dogs and that they show a similar response pattern to anterior temporal voice areas in humans.
Dogs also demonstrate sophisticated social cognition by associating behavioral cues with abstract meanings. One such class of social cognition involves the understanding that others are conscious agents. Research indicates that dogs are capable of interpreting subtle social cues, and appear to recognize when a human or dog's attention is focused on them. To test this, researchers devised a task in which a reward was hidden underneath one of two buckets. The experimenter then attempted to communicate with the dog to indicate the location of the reward by using a wide range of signals: tapping the bucket, pointing to the bucket, nodding to the bucket, or simply looking at the bucket. The results indicated that domestic dogs were better than chimpanzees, wolves, and human infants at this task, and even young puppies with limited exposure to humans performed well.(pp1634–6)
One study investigated if dogs engaged in partnered play change their behavior depending on the attention-state of their partner. Those studies showed that play signals were only sent when the dog was holding the attention of its partner. If the partner was distracted, the dog instead engaged in attention-getting behavior before sending a play signal.
Learning by rank
In a problem-solving experiment, dominant dogs generally performed better than subordinates, but only when they observed a human demonstrator’s actions. This indicates that social rank affects performance in social learning situations. In social groups with a clear hierarchy, dominant individuals are the more influential demonstrators and the knowledge transfer will, therefore, be unidirectional. If dog-human groups are regarded as hierarchical social units, humans are usually considered as the leaders, meaning the human will be the most influential demonstrator for the dominant dog. Subordinate dogs will learn better from the dominant dog that is adjacent in the hierarchy.
Puppies learn behaviors quickly by following examples set by experienced dogs. This form of intelligence is not peculiar to those tasks dogs have been bred to perform, but can be generalized to myriad abstract problems. For example, Dachshund puppies that watched an experienced dog pull a cart by tugging on an attached piece of ribbon in order to get a reward from inside the cart learned the task fifteen times faster than those left to solve the problem on their own.
Dogs can also learn by mimicking human behaviors. In one study, puppies were presented with a box, and shown that, when a handler pressed a lever, a ball would roll out of the box. The handler then allowed the puppy to play with the ball, making it an intrinsic reward. The pups were then allowed to interact with the box. Roughly three quarters of the puppies subsequently touched the lever, and over half successfully released the ball, compared to only 6% in a control group that did not watch the human manipulate the lever.
Learning by inference
A study found that handing an object between experimenters who then used the object's name in a sentence successfully taught an observing dog each object's name, allowing the dog to subsequently retrieve the item.
In humans, "fast mapping" is the ability to form quick and rough hypotheses about the meaning of a new word after only a single exposure. In 2004, a study with Rico, a Border Collie, showed he was able to fast map. Rico initially knew the labels of over 200 different items. He inferred the names of novel items by exclusion learning and correctly retrieved those novel items immediately and also 4 weeks after the initial exposure. Rico was also able to interpret phrases such as "fetch the sock" in terms of its component words (rather than considering its utterance to be a single word). Rico could also give the sock to a specified person. This retrieval rate is comparable to the performance of 3-year-old humans. In 2008, Betsy, also a Border Collie, who knew over 340 words and was able to connect an object with a photographic image of the object, despite having seen neither before.
Memory and recall
In 2013, a study documented the learning and memory capabilities of a border collie, "Chaser", who had learned the names and could associate by verbal command over 1,000 words at the time of its publishing. Chaser was documented as capable of learning the names of new objects "by exclusion", and capable of linking nouns to verbs. It is argued that central to the understanding of the border collie's remarkable accomplishments is the dog's breeding background - collies bred for herding work are uniquely suited for intellectual tasks like word association which may require the dog to work "at a distance" from their human companions, and the study credits this dog's selective breeding in addition to rigorous training for her intellectual prowess. Rico could remember items 4 weeks after the initial exposure.
In 2014, a whole genome study of the DNA differences between wolves and dogs found that dogs did not show a reduced fear response, they showed greater synaptic plasticity. Synaptic plasticity is widely believed to be the cellular correlates of learning and memory and this change may have altered the learning and memory abilities of dogs.
Intelligence includes cognition (as above), planning, creativity, and problem solving. In 1976, the first intelligence test for dogs was developed with assessments to test short term memory, agility, ability to adapt, problem solving, unique detour problems, and to see how the dog reacts to conditions which he or she finds unacceptable. The performances of individual dogs were compared to over 100 dogs on which the test was standardized and breed norms were developed. Stanley Coren ranked dog breeds by intelligence in his book The Intelligence of Dogs based on surveys done of dog obedience judges, the article for which contains a summary of the rankings obtained.
Studies suggest that dogs may feel complex emotions, like jealousy and anticipation. In his 1996 book Good Natured, ethologist Frans de Waal discusses an experiment on guilt and reprimands conducted on a female Siberian husky. The dog had the habit of shredding newspapers, and when her owner returned home to find the shredded papers and scold her she would act guilty. However, when the owner himself shredded the papers without the dog's knowledge, the dog "acted just as 'guilty' as when she herself had created the mess." De Waal concludes that the "guilt" displayed by dogs is not true guilt but rather the anticipation of the behavior of an angry superior in a given situation.
Studies have shown that humans' gaze instinctively moves to the left in order to watch the right side of a person's face, which is related to use of right hemisphere brain for facial recognition, including human facial emotions. Research indicates that dogs share this instinct when meeting a human and not other animals or other dogs. As such, they are the only non-primate species known to do so. Dogs can discriminate the emotional expressions of human faces.
One study indicated that sex-specific dynamics in repeated problem-solving tasks might be an important contributor to individual differences in cognitive performance of pet dogs.
A study showed compelling evidence that Dingos (Canis dingo) can outperform domestic dogs in non-social problem-solving experiment, indicating that domestic dogs may have lost much of their original problem-solving abilities once they joined humans. Another study indicated that after undergoing training to solve a simple manipulation task, dogs that are faced with an insoluble version of the same problem look at the human, while socialized wolves do not. Modern domestic dogs use humans to solve their problems for them.
Following human cues
Dogs are able to read and react appropriately to human body language such as gesturing and pointing, and to understand human voice commands.
Studies indicate that dogs show human-like social cognition. Dogs (and wolves) have been shown to follow more complex point types made with body parts other than the human arm and hand (e.g. elbow, knee, foot). Dogs (and wolves) have the cognitive capacity for prosocial behavior toward humans, however it is not guaranteed. For canids to perform well on traditional human-guided tasks (e.g. following the human point) both relevant lifetime experiences with humans - including socialization to humans during the critical period for social development - and opportunities to associate human body parts with certain outcomes (such as food being provided by human hands, a human throwing or kicking a ball, etc.) are required.
Dogs can follow the human pointing gesture. New Guinea Singing dogs are a half-wild proto-dog endemic to the remote alpine regions of New Guinea and these can follow a human pointing gesture. So can Dingoes in the remote outback of Australia. These both demonstrate an ability to read human gestures that arose early in domestication and did not require human selection. "Humans did not develop dogs, we only fine-tuned them down the road.":92
The dog has a predisposition to exhibit a social intelligence that is uncommon in the animal world. Dogs demonstrate a theory of mind by engaging in deception, including one example where a dog hid a stolen treat by sitting on it until the rightful owner of the treat left the room. Although this could have been accidental, it suggests that the thief understood that the treat's owner would be unable to find the treat if it were out of view.
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