Dog intelligence or dog cognition is the process in dogs of acquiring, storing in memory, retrieving, combining, comparing, and using in new situations information and conceptual skills.
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, and a border collie named 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.
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.
Most modern research on dog cognition has focused on pet dogs living in human homes in developed countries, which is only a small fraction of the dog population and dogs from other populations may show different cognitive behaviors. Breed differences possibly could impact on spatial learning and memory abilities.
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.
Perception refers to mental processes through which incoming sensory information is organized and interpreted in order to represent and understand the environment. Perception includes such processes as the selection of information through attention, the organization of sensory information through grouping, and the identification of events and objects. In the dog, olfactory information (the sense of smell) is particularly salient (compared with humans) but the dogs senses also include vision, hearing, taste, touch and proprioception. There is also evidence that dogs sense 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 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 response pattern in the anterior temporal voice areas that is similar to that in humans.
Social learning: observation and rankEdit
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 cuesEdit
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. 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). Dogs tend to follow hand/arm pointed directions more when combined with eye signaling as well. In general, dogs seems to use human cues as an indication on where to go and what to do.  Overall, dogs appear to have several cognitive skills necessary to understand communication as information; however, findings on dogs' understanding of referentiality and others' mental states are controversial and it is not clear whether dog themselves communicate with informative motives. 
For canines 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.
In 2016, a study of water rescue dogs that respond to words or gestures found that the dogs would respond to the gesture rather than the verbal command.
Learning and using wordsEdit
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.
One limitation in the study of emotions in non-human animals, is that they cannot verbalise to express their feelings. However, dogs' emotions can be studied indirectly through cognitive tests, called cognitive bias test, which measure a cognitive bias and allow to make inference about the mood of the animal. Researchers have found that dogs suffering from separation anxiety have a more negative cognitive bias, compared to dogs without separation anxiety.  On the other hand, when dogs' separation anxiety is treated with medications and behaviour therapy, their cognitive bias becomes less negative than before treatment.  Also administration of oxytocin, rather than a placebo, induces a more positive cognitive bias and positive expectation in dogs.  It is therefore suggested that the cognitive bias test can be used to monitor positive emotional states and therefore welfare in dogs. 
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.
Learning by inferenceEdit
Dogs have the ability to train themselves and learn behaviors through interacting and watching other dogs.
Theory of mindEdit
"Theory of mind" is the ability to attribute mental states—beliefs, intents, desires, pretending, knowledge, etc.—to oneself and others and to understand that others have beliefs, desires, intentions, and perspectives that are different from one's own. 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. A study found that dogs are able to discriminate an object that a human partner is looking for based on its relevance for the partner and they are more keen on indicating an object that is relevant to the partner compared to an irrelevant one; this suggests that dogs might have a rudimental version of some of the skills necessary for theory of mind. 
- Humphreys, L.G. (1979). "The construct of general intelligence". Intelligence. 3 (2): 105–120. doi:10.1016/0160-2896(79)90009-6.
- Tomasello, M.; Kaminski, J. (2009). "Like Infant, Like Dog". Science. 325 (5945): 1213–4. doi:10.1126/science.1179670. PMID 19729645.
- Hare, Brian & Woods, Venessa (2013). The Genius of Dogs. Penguin Publishing Group.
- Hare, B; Tomasello, M (2005). "Human-like social skills in dogs?". Trends in Cognitive Sciences. 9 (9): 439–44. doi:10.1016/j.tics.2005.07.003. PMID 16061417.
- Shipman P (2011) The Animal Connection. A New Perspective on What Makes Us Human. New York: W.W. Norton and Co
- Bradshaw J (2011) Dog Sense. How the New Science of Dog Behavior Can Make You a Better Friend. New York: Basic Books
- Hare, B. (2002). "The Domestication of Social Cognition in Dogs". Science. 298 (5598): 1634–6. Bibcode:2002Sci...298.1634H. doi:10.1126/science.1072702. PMID 12446914.
- Hare, Brian; Tomasello, Michael (September 2005). "Human-like social skills in dogs?". Trends in Cognitive Sciences. 9 (9): 439–444. doi:10.1016/j.tics.2005.07.003. PMID 16061417.
- Téglás, Ernő; Gergely, Anna; Kupán, Krisztina; Miklósi, Ádám; Topál, József (February 2012). "Dogs' Gaze Following Is Tuned to Human Communicative Signals". Current Biology. 22 (3): 209–212. doi:10.1016/j.cub.2011.12.018. PMID 22226744.
- Kaminski, J., Call, J. and Fischer, J. (2004). "Word learning in a domestic dog: Evidence for "fast mapping"". Science. 304 (5677): 1682–1683. Bibcode:2004Sci...304.1682K. doi:10.1126/science.1097859. PMID 15192233.
- Mendl, M.; Brooks, J.; Basse, C.; Burman, O.; Paul, E.; Blackwell, E.; Casey, R. (2010). "Dogs showing separation-related behaviour exhibit a 'pessimistic' cognitive bias" (PDF). Current Biology. 20 (19): R839–R840. doi:10.1016/j.cub.2010.08.030. PMID 20937467.
- Bekoff, Marc (January 2007). The Emotional Lives of Animals: A Leading Scientist Explores Animal Joy, Sorrow, and Empathy — and Why They Matter. New World Library. ISBN 978-1-57731-502-5.
- Smithsonian Magazine online article
- Li, Y.; Wang, G.-D.; Wang, M.-S.; Irwin, D. M.; Wu, D.-D.; Zhang, Y.-P. (2014). "Domestication of the Dog from the Wolf Was Promoted by Enhanced Excitatory Synaptic Plasticity: A Hypothesis". Genome Biology and Evolution. 6 (11): 3115–3121. doi:10.1093/gbe/evu245. PMC . PMID 25377939.
- Udell, M.A.R., Dorey, N.R. and Wynne, C.D.L. (2010). "What did domestication do to dogs? A new account of dogs' sensitivity to human actions". Biological Reviews. 85 (2): 327–345. doi:10.1111/j.1469-185X.2009.00104.x. PMID 19961472.
- Head, E., Mehta, R., Hartley, J., Kameka, M., Cummings, B.J., Cotman, C.W., Ruehl, W.W. and Milgram, N.W. (1995). "Spatial learning and memory as a function of age in the dog". Behavioral Neuroscience. 109 (5): 851–858. doi:10.1037/0735-7044.109.5.851. PMID 8554710.
- Coon, Kathy (1977). the dog intelligence test. Avon Books. ISBN 0-380-01903-5.
- Schacter, Daniel (2011). Psychology. Worth Publishers.
- Alexandra Horowitz (2016). "2-Smeller". Being a Dog:Following the Dog Into a World of Smell. Scribner New York. p. 29.
- Melissa Dahl (2016). "Apparently Dogs Can Tell Time With Their Noses". The Science of Us - NYMag.
- Bensky, Miles K.; Gosling, Samuel D.; Sinn, David L. (2013). "Chapter 5: The world from a dog's point of view: A review and synthesis of dog cognition research". In Brockmann, H. Jane; et al. Advances in the Study of Behavior. Advances in the Study of Behavior. 45. Elsevier. pp. 209–406. doi:10.1016/B978-0-12-407186-5.00005-7.
- Coren, Stanley (1995). The Intelligence of Dogs: A Guide to the Thoughts, Emotions, and Inner Lives of Our Canine Companions. Bantam Books. ISBN 0-553-37452-4.
- Coren, Stanley (2013-10-08). "Do Dogs Know The Difference Between Dogs and Other Animals?". Psychology Today. Retrieved 10 April 2015.
- "Dogs' brain scans reveal vocal responses". BBC World Service. Retrieved 9 August 2015.
- "How Dogs Learn". National Animal Interest Alliance. Retrieved 4 July 2014.
- Horowitz, Alexandra (2009). "Attention to attention in domestic dog (Canis familiaris) dyadic play". Journal Animal Cognition. Springer Berlin / Heidelberg. 12 (1): 107–18. doi:10.1007/s10071-008-0175-y. PMID 18679727.
- Adler, Leonore Loeb; Adler, Helmut E. (2004). "Ontogeny of observational learning in the dog (Canis familiaris)". Developmental Psychobiology. 10 (3): 267–271. doi:10.1002/dev.420100310. PMID 863122.
- Pongrácz, Péter; Bánhegyi, Petra; Miklósi, Ádám (2012). "When rank counts—dominant dogs learn better from a human demonstrator in a two-action test". Behaviour. Brill Publishers. 149 (1): 111–132. doi:10.1163/156853912X629148.
- Miklósi, Adam; et al. (29 April 2003). "A simple reason for a big difference: wolves do not look back at humans, but dogs do". Current Biology. 13 (9): 763–766. doi:10.1016/S0960-9822(03)00263-X. PMID 12725735.
- Gjersoe, Nathalia (Sep 23, 2013). "Dogs: an uncomplicated relationship". The Guardian.
- Kubinyi, E.; Topal, J. & Miklosi, A. (2003). "Dogs (canis familiaris) learn their owners via observation in a manipulation task". Journal of Comparative Psychology. 117 (2): 156–165. doi:10.1037/0735-7036.117.2.156. PMID 12856786.
- Hare, B.; Brown, M.; Williamson, C. & Tomasello, M. (Nov 2002). "The domestication of social cognition in dogs". Science. 298 (5598): 1634–6. Bibcode:2002Sci...298.1634H. doi:10.1126/science.1072702. ISSN 0036-8075. PMID 12446914.
- Udell, M. A. R, Spencer, J. M., Dorey, N. R., & Wynne, C. D. L. (2012). "Human-Socialized Wolves Follow Diverse Human Gestures... And They May Not Be Alone". International Journal of Comparative Psychology. 25 (2): 97–117.
- Kaminski, Juliane; Nitzschner, Marie. "Do dogs get the point? A review of dog–human communication ability". Learning and Motivation. 44 (4): 294–302. doi:10.1016/j.lmot.2013.05.001.
- Kaminski, J., & Piotti, P. (2016). Current trends in dog-human communication: do dogs inform?. Current Directions in Psychological Science, 25(5), 322-326.https://doi.org/10.1177/0963721416661318
- Udell, M.A.R. (2014). "10. A Dog's-Eye View of Canine Cognition". In A. Horowitz. Domestic Dog Cognition and Behavior. Springer-Verlag Berlin Heidelberg. doi:10.1007/978-3-642-53994-7_10.
- d'Aniello, Biagio; Scandurra, Anna; Alterisio, Alessandra; Valsecchi, Paola; Prato-Previde, Emanuela (2016). "The importance of gestural communication: A study of human–dog communication using incongruent information". Animal Cognition. 19 (6): 1231. doi:10.1007/s10071-016-1010-5. PMID 27338818.
- Fugazza, Claudia; Pogány, Ákos; Miklósi, Ádám (2016). "Recall of Others' Actions after Incidental Encoding Reveals Episodic-like Memory in Dogs". Current Biology. 26 (23): 3209. doi:10.1016/j.cub.2016.09.057. PMID 27889264.
- Morell, Virginia (March 2008). "Minds of their Own". National Geographic. Retrieved 2008-10-13.
- McKinley, Sue; Young, Robert J (2003). "The efficacy of the model-rival method when compared to operant conditioning for training domestic dogs to perform a retrieval-selection task". AABS. 81 (4): 357–365. doi:10.1016/S0168-1591(02)00277-0.
- Pilley, John (2013). Chaser: Unlocking the genius of the dog who knows a thousand words. Houghton Mifflin Harcourt. ISBN 9780544102576.
- "Test reveals dogs' jealous side". BBC News. 2008-12-08. Retrieved 2010-05-01.
- "Functional MRI in Awake Unrestrained Dogs". PLoS One. 2012-05-11.
- de Waal, Frans (1996). Good Natured. Harvard University Press. pp. 107–108. ISBN 0-674-35660-8.
- Mendl, Michael; Brooks, Julie; Basse, Christine; Burman, Oliver; Paul, Elizabeth; Blackwell, Emily; Casey, Rachel. "Dogs showing separation-related behaviour exhibit a 'pessimistic' cognitive bias". Current Biology. 20 (19): R839–R840. doi:10.1016/j.cub.2010.08.030.
- Karagiannis, Christos I.; Burman, Oliver HP; Mills, Daniel S. (2015-03-28). "Dogs with separation-related problems show a "less pessimistic" cognitive bias during treatment with fluoxetine (Reconcile™) and a behaviour modification plan". BMC Veterinary Research. 11: 80. doi:10.1186/s12917-015-0373-1. ISSN 1746-6148.
- Kis, Anna; Hernádi, Anna; Kanizsár, Orsolya; Gácsi, Márta; Topál, József. "Oxytocin induces positive expectations about ambivalent stimuli (cognitive bias) in dogs". Hormones and Behavior. 69: 1–7. doi:10.1016/j.yhbeh.2014.12.004.
- Piotti, P. (2017). Positive emotions and quality of life in dogs. Animal Sentience: An Interdisciplinary Journal on Animal Feeling, 2(14), 17.
- Corsin A. Müller1, Kira Schmitt, Anjuli L.A. Barber, Ludwig Huber (2015). "Dogs can discriminate the emotional expressions of human faces". Current Biology. 25 (5): 601–605. doi:10.1016/j.cub.2014.12.055. PMID 25683806.
- K Guo; C Hall; S Hall; K Meints; D Mills (2007). "Left gaze bias in human infants, rhesus monkeys, and domestic dogs". Perception. 36 ECVP. Retrieved 24 June 2010.
- Duranton, Charlotte; Rödel, Heiko G.; Bedossa, Thierry; Belkhir, Séverine (2015). "Inverse sex effects on performance of domestic dogs (Canis familiaris) in a repeated problem-solving task". Journal of Comparative Psychology. 129 (1): 84–7. doi:10.1037/a0037825. PMID 25181448.
- Smith, B.; Litchfield, C. (2010). "How well do dingoes (Canis dingo) perform on the detour task". Animal Behaviour. 80: 155–162. doi:10.1016/j.anbehav.2010.04.017.
- "Why dogs are more like humans than wolves". Smithsonian Magazine.
- "The brilliance of the dog mind". Scientific American.
- Tiffany O'Callaghan (2013). "Survival of the Friendliest". New Scientist.
- Stanley., Coren, (2004). How dogs think : understanding the canine mind. New York: Free Press. ISBN 0743222326. OCLC 55588158.
- Premack, D. G.; Woodruff, G. "Does the chimpanzee have a theory of mind?". Behavioral and Brain Sciences. 1: 515–526. doi:10.1017/s0140525x00076512.
- Piotti, Patrizia; Kaminski, Juliane (2016-08-10). "Do Dogs Provide Information Helpfully?". PLOS ONE. 11 (8): e0159797. doi:10.1371/journal.pone.0159797. ISSN 1932-6203.
- Horowitz, Alexandra. "Inside of a Dog: What Dogs, See, Smell, and Know" (2009 Scribner).
- Bradshaw, John. "Dog Sense" (2012 Basic Books).
- Hare, Brian & Woods, Venessa. The Genius of Dogs (2013 Penguin Publishing Group) Reveals research findings about how dogs think and how we humans can have deeper relationships with them.
- Pilley, John and Hinzmann, Hilary. Chaser: Unlocking the Genius of the Dog Who Knows a Thousand Words (2013 Houghton Mifflin Harcourt)
- Miklosi, Adam. Dog Behaviour, Evolution, and Cognition (2016 Oxford University Press) Provides a basis for a complete dog behavioural biology based on concepts derived from contemporary ethology.
- The Intelligence of Dogs