As with humans, dog intelligence refers to such cognitive skills such as short and long-term memory, sensitivity to social cues, planning, creativity, and problem solving. The first intelligence test for dogs was developed in 1976. It included measurements of short-term memory, agility, and ability to solve problems such as detouring to a goal. It also assessed the ability of a dog to adapt to new conditions and cope with emotionally difficult situations. The test was administered to 100 dogs and standardized, and breed norms were developed. Stanley Coren used surveys done by dog obedience judges to rank dog breeds by intelligence and published the results in his book The Intelligence of Dogs.
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, many dogs readily respond to social cues common to humans, quickly learn the meaning of words, show cognitive bias and exhibit emotions that seem to reflect those of humans.
Research suggests 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 experiments. Another study indicated that after being trained to solve a simple manipulation task, dogs that are faced with an insoluble version of the same problem look at a nearby human, while socialized wolves do not. Thus, modern domestic dogs seem to use humans to solve some of their problems for them.
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.
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 also 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.
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.
The concept of "object permanence" refers to the ability of an animal to understand that objects continue to exist even when they have moved outside of their field of view. This ability is not present at birth, and developmental psychologist Jean Piaget described six stages in the development of object permanence in human infants. A similar approach has been used with dogs, and there is evidence that dogs go through similar stages and reach the advanced fifth stage by an age of 8 weeks. At this stage they can track "successive visible displacement" in which the experimenter moves the object behind multiple screens before leaving it behind the last one. It is unclear whether dogs reach Stage 6 of Piaget's object permanence development model.
A study in 2013 indicated that dogs appear to distinguish dogs from other animals regardless of breed, size, color or shape.
In 2014, a study using magnetic resonance imaging demonstrated that voice-response areas exist in the brains of dogs and that they show a response pattern in the anterior temporal voice areas that is similar to that in humans.
Social learning: observation and rank
One study investigated whether dogs engaged in partnered play would adjust their behavior to the attention-state of their partner. The experimenters observed 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.
Puppies learn behaviors quickly by following examples set by experienced dogs. This form of intelligence is not particular to those tasks dogs have been bred to perform, but can be generalized to various abstract problems. For example, Dachshund puppies were set the problem of pulling a cart by tugging on an attached piece of ribbon in order to get a reward from inside the cart. Puppies that watched an experienced dog perform this task learned the task fifteen times faster than those left to solve the problem on their own.
The social rank of dogs affects their performance in social learning situations. In social groups with a clear hierarchy, dominant individuals are the more influential demonstrators and the knowledge transfer tends to be unidirectional, from higher rank to lower. In a problem-solving experiment, dominant dogs generally performed better than subordinates when they observed a human demonstrator's actions, a finding that reflects the dominance of the human in dog-human groups. Subordinate dogs learn best from the dominant dog that is adjacent in the hierarchy.
Following human cues
Dogs show human-like social cognition in various ways. For example, dogs can react appropriately to human body language such as gesturing and pointing, and they also understand human voice commands. For example, 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.
Similarly,  dogs may be guided by cues indicating the direction of a human's attention. In one task a reward was hidden under one of two buckets. The experimenter then indicated the location of the reward by tapping the bucket, pointing to the bucket, nodding at the bucket, or simply looking at the bucket. The dogs followed these signals, performing better than chimpanzees, wolves, and human infants at this task; even puppies with limited exposure to humans performed well.(pp1634–6)
Dogs can follow the direction of pointing by humans. New Guinea singing dogs are a half-wild proto-dog endemic to the remote alpine regions of New Guinea and these can follow human pointing as can Australian dingoes. These both demonstrate an ability to read human gestures that arose early in domestication without human selection. "Humans did not develop dogs, we only fine-tuned them down the road.":92 Dogs (and wolves) have also been shown to follow more complex pointing made with body parts other than the human arm and hand (e.g. elbow, knee, foot).
It should be noted finally that 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 phase for social development—and opportunities to associate human body parts with certain outcomes (such as food being provided by humans, a human throwing or kicking a ball, etc.) are required.
Memory: learning and using words
Various studies have shown that dogs readily learn the names of objects and can retrieve an item from among many others when given its name. For example, in 2008, Betsy, a border collie, knew over 340 words by the retrieval test, and she was also to connect an object with a photographic image of the object, despite having seen neither before. In another study, a dog watched as experimenters handed an object back and forth to each other while using the object's name in a sentence. The dog subsequently retrieved the item given its name. A border collie, "Chaser", learned the names of over 1,000 objects and retrieved them by verbal command.
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 items. He inferred the names of novel items by exclusion, that is, by knowing that the novel item was the one that he did not already know. Rico correctly retrieved such novel items immediately and four weeks after the initial exposure. Rico was also able to interpret phrases such as "fetch the sock" by its component words (rather than considering its utterance to be a single word). Rico could also give the sock to a specified person. This performance is comparable to that of 3-year-old humans.
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.
Studies suggest that dogs feel complex emotions, like jealousy and anticipation. However, behavioral evidence of seemingly human emotions must be interpreted with care. For example, 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 dog did not display true guilt as humans understand it, but rather simply the anticipation of reprimand.
There is evidence that dogs can discriminate the emotional expressions of human faces. In addition, they seem to respond to faces in somewhat the same way as humans. For example, humans tend to gaze at the right side of a person's face, which may be related to the use of right brain hemisphere for facial recognition. Research indicates that dogs also fixate the right side of a human face, but not that of other dogs or other animals. Dogs are the only non-primate species known to do so.
Sex-specific dynamics are an important contributor to individual differences in cognitive performance of pet dogs in repeated problem-solving tasks.
Captive-raised dingoes (Canis dingo) can outperform domestic dogs in non-social problem-solving. Another study indicated that after undergoing training to solve a simple manipulation task, dogs faced with an unsolvable version of the same problem look at the human, whereas socialized wolves do not. Modern domestic dogs use humans to solve their problems for them.
Theory of mind
There is some evidence that dogs demonstrate a theory of mind by engaging in deception. For example, one observer reported that 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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