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Domesticity and Cognition in Dogs. Sensitivity to human social cues. Sensitivity to human social stimuli reliably alter behavior in presence of such stimuli to obtain reinforcement These behaviors emerge after instruction or mediation of human companion
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Sensitivity to human social cues • Sensitivity to human social stimuli • reliably alter behavior in presence of such stimuli to obtain reinforcement • These behaviors emerge after instruction or mediation of human companion • Theory of Mind and Dogs: Heyes (1998): “…an animal with a theory of mind believes that mental states play a causal role in generating behavior and infers the presence of mental states in others by observing their appearance and behavior under various circumstances”. • Several sets of data point to such an ability in dogs
Ontogeny of social behavior in Canids • Domestication results in both physical and behavioral changes • Physical changes include: • Larger size variation: dwarf and giant • Piebald coat color • Reproductive cycle changes • Changes in hair, shortened tails, floppy ears • Social changes: • Lack of development of fear to humans • Exhibiting play behavior in adulthood • Prolonged juvenile period
Ontogeny of Social Behavior in Canids • Most important: Paedomorphosis • Retention of juvenile traits into adulthood • Physical characteristics • Behavior characteristics • Important: • Changes in head: muzzle, ears, coat, eyes, tail • More juvenile signaling and extended play behavior in place of adult aggression/antagonistic signaling • Extended play • Reduced need for adult-type signaling
Physical and Behavioral differences • Sharpness of features • Pointy ears, eyes, snout • Intense eyes • http://www.youtube.com/watch?v=1QqsSw5BDA8&feature=related • Roundness of features • Rounded eyes, floppy ears, “smiling” • Softened eyes • http://www.youtube.com/watch?v=B4Z9dUkbq1g&feature=related
Paedomorphosis • Wolf pups have much shorter development span • Good motor by 3 weeks of age • Domestic dogs: good motor control comes around 10-12 weeks • Wolf pups show complex social behavior much sooner than domestic dogs • Dogs begin socialization once begin to walk (about 3 weeks) • Continue to form primary relationships until at least 12 weeks to 16 weeks (best time for adopting a puppy is 8-12 weeks) • Socialization to both dogs and humans is critical for dog development • Shelter dogs • Dogs weaned/adopted too soon • Working dogs: avoid human contact, want them to bond to cattle or sheep
Farm Fox experiment • DimitriBelyaev: 1950 to today (REF) • Manipulated breeding of foxes on fox farm • Selected breeders based on behavioral characteristics: mostly sensitivity to humans • Only about 3% of males, 10% of females selected in first generation • Not reared with humans, just a 1 time test • Rapid effects on behavior and morphology • By 6th generation: begin to see domestication elite: no fear of humans • By 8th generation: morphological changesbegin • By 42 generations: about 70% meet criteria for domestication elite
Farm Fox experiment • Interesting physical changes: Note, NOT selected for these traits • Trait changes included: • Floppy ears; Rolled tails; Splotchy coats • Shorter tails and legs • Correlated with “tameness” • Behavioral Changes • Extended developmental period for bonding/attachment • Exhibit juvenile play traits in adulthood • Slower to develop adult behavior repertoires • Hormonal changes correspond with this: delay in onset of innate fear response • Lengthened developmental periods • Typical fox: 45 days or about 5/5 weeks. • Marked by onset of fear and avoidance and reduction in exploratory behavior • Generations 28-30: Increased to about 12 weeks and often longer • Similar to domestic dogs
Domestication hypothesis (Hare): • Domestication = sufficient cause of canid’s sensitivity to human social behavior • Human and dog convergent evolution of advanced social cognition in response to similar social selection pressures • Brian Hare: number of comparisons of wolves versus dogs and domesticated foxes: • Dogs better at following human gestures; Wolves only good at point/gaze • Socialized wolves improve over unsocialized wolves • Experimentally domesticated foxes performed like dogs • As get older, wolves prefer to be with another wolf rather than a human • Most dogs are the opposite: preference for human interaction • Hare argues against ontogeny as important factor • Ontogeny = the entire sequence of events involved in the development of an individual organism • Domestication hypothesis argues genetic changes sufficient
Problems with Domestication Hypothesis • Not account for differences in developmental windows • With shorter window, shorter set of experiences and opportunity to learn • Can’t test dogs/wolves of same chronological age, but must compare at same developmental age • Dogs exposed to experimental manipulation while still in sensitive period of socialization require less experience to produce greater effect
Proximity to humans = important factor • Domestication correlates with proximity to humans • Domestication theory does not account for exposure effects • Hard to get proper comparison group • Wild wolves with no contact with humans (dangerous) • If use tame wolves, have the human issue • Wild dogs also hard to work with! • Studies which have attempted to account for human proximity have found that contact with humans is an important factor • Shelter dogs show more “wild-like” behavior; increased fear and aggression • Dogs socialized after sensitive period show similar patterns
Conditioning/:Learning Experiences • With human contact comes opportunity to become conditioned to human behavior • Serendipity in learning human social cues: Get reinforced more often! • Domestic dogs learn human cues faster than wolves • Domestic dogs are reinforced for appropriate response to humans almost constantly • Learn how to “manipulate” owners • “guilty look” = I look “guilty” then I get back with the pack • Not necessarily have human emotion with it, but show appropriate response due to conditioning
Arguments against domestication hypothesis • Domestic dogs have smaller brains than wolves • Socialized wolves can learn human signals as well as dogs • Improbable that dogs have innate ability to exploit behavior of humans • Not conspecifics • Different morphology and behavior • E.g., the “hat” problem • Ontogeny plays crucial role in development of effective conspecific social interactions in canids (and many other species)
Two stage hypothesis • Sensitivity of canid to human social cues depends on 2 types of ontogenic experiences • Interactions with humans during sensitivity developmental period leading to acceptance of humans as social companions • Learning that is not restricted to one particular phase of development • Learn to use location and movement of human body parts to locate sought-after objects • Domestication not qualitatively change behavior, but has changed quantity and duration of certain behaviors
Predictions of Two-Stage theory • Both wild and domestic canids have • phylogenetic prerequisites to respond to human social signals • have mutually beneficial interactions with humans • Preparedness (Seligman, 1967; also Bolles 1967; Timberlake, 2001) • Biological boundaries • Prepared to attend to certain cues because these increase probability of survival • But: this preparedness to respond requires experience to elicit and shape beneficial behaviors • Dog will become socialized to whatever it is around: • Other dogs • Sheep or cattle • Humans • Learns behavior that works the best
WHY paedomorphosis? WHY extended play? • Observe two dogs meeting and greeting: • Dog comes face to snout with another dog. • An intricate dance begins: each movement appears precisely choreographed. • The dogs visually inspect each other, • sniff each other, • walk circles around each other. • And then the fight begins. • Could be real aggression; could be play-fighting? • How do dogs tell the difference? • What is play? • James L. Gould and Carol Grant Gould • describe any behavior that does not have any apparent adaptive function, that is, it serves no obvious purpose.
Many animals engage in “Purposeless Activities” • Heinrich and Smolker: Ravens (Corvuscorax):snowboarding. • Ravens in Alaska and Northern Canada are known to slide down steep, snow-covered roofs. • When they reach the bottom, they walk or fly back to the top, and repeat the process over and over again. • In Maine, ravens were observed tumbling down small mounds of snow, sometimes while holding sticks between their talons. “ • There appears to be no obvious utilitarian function for sliding behavior • DOES look highly similar to playground behavior in children: they also show repetitive sliding activity.
Animal Play • Herring gulls (Larusargentatus): play with clam shells • feed on clams by dropping them onto hard surfaces such as rocks or paved roads. • If they drop them from high enough, the clamshell might crack, providing access to the juicy snack waiting inside. • Sometimes, rather than letting clams drop to the ground, herring gulls try to catch the clam in mid-air. • Other shorebirds play this game of catch as well, including black-backed gulls, common gulls, and Pacific gulls.
Animal Play • . Gamble and Cristol noted “rules” of the game. • younger gulls played drop-catch more often than mature gulls. • drop-catch was performed over soft ground more often than over hard or rocky surfaces. • That is: if the gull had dropped the clams on the softer ground, it was extremely unlikely that they would break open. • drop-catch behavior far more likely to occur when the gull was carrying an object that wasn't a clam. • drop-catchedclams were less likely to be eaten than dropped ones. • Most interesting: drop-catches were more common when the wind was stronger, • Suggests that gulls engaged in more challenging taskss • Are drop-catching gulls are simply having fun.
Solitary vs. social play • Solitary play • Play involving individual animals • Both the snowboarding ravens and the drop-catching gulls are examples of solitary play, • Social play is also common. • Play between group members or even across species • Involves specific signal patterns. • For example, Play Bow (Beckoff) • Dogs and their canid cousins, wolves and coyotes, bow their heads down • The play bow, like other signals, serves as a means of broadcasting the message, "I want to play!" • Also maintains on-going play. • Why important? • Several behaviors exhibited during play also used in other contexts • e.g., aggressive, predatory, and sexual encounters. • Bekoff: bow is used more often before and after actions that could be misinterpreted as non-playful • infant and adult dogs used the play bow directly before and after mock bites 74% of the time, • juvenile wolves 79% of the time, • young coyotes 92% of the time. • Play bow “frames” the biting behavior as play rather than aggression
Purpose of Play • We may misunderstand play behaviors because these behaviors seem to lack of any adaptive or evolutionary function- but we are missing the point! • Play = practice for “adult behavior” • young animals borrow actions from aggressive, hunting, foraging, or sexual behaviors • Appears that play may serve as a form of practice. • Play might help animals become more psychologically flexible. • Fagen: "the distinctive aspect of playful practice and learning is that they are generic and variational, requiring varied experiences and stressing interactions between simple components." • the variation within “play actions” may better prepare an animal to respond adequately in future aggressive or sexual encounters.
Why is this important? • Drives research questions: • Is it nature or nurture that is more important • How does nature interact with nurture • Suggests need to examine developmental stages more closely • Authors caution: standardization of methods • Several research questions begin to emerge: • Breed differences? • Experience Differences? Shelter vs. fostering dogs for adoption • Deaf, blind or deaf/blind versus typical dogs: What is effect on socialization? • What cognitive abilities do dogs have? • http://www.youtube.com/user/DukeDogCognition#p/a/u/2/c5hebBJdtrE
DIFFERENCES IN PLAY BETWEEN DEAF AND HEARING DOGS (CANIS LUPIS FAMILIARIS).Undergraduate Assistants: Jacquelyn Johnson and Terry Coughlin • Subjects: 7 deaf dogs and 7 hearing dogs • Dogs were videotaped during 5 minute free play • Dogs were paired such that play bouts are recorded for: • Deaf dog and deaf dog: N=23 pairings • Deaf dog to hearing dog: N=12 pairings • Data analysis: • videotape sessions were analyzed by dividing the play sessions into 10 sec-bouts. • Undergraduate research assistants (URAs) watched the videos using Horowitz’s scoring system: • Play signals: • Attention getting play behavior • Non-attention getting play behavior • Other non play specific behaviors Replication of: Horowitz, A. (2009). Attention to attention in domestic dog (Canis familiaris) dyadic play. Animal Cognition, 12, 107-118.
Results: • A Mann-Whitney Ranks test, a nonparametric version of t-tests, were used to assess differences between deaf and hearing dogs for each of the play behaviors. • Significant differences in: • Play bow: :z=-2.197, p=0.28 • Hearing dogs showed MORE play bows • Bow head: z=-1.97, p=.047 • Hearing dogs bowed away head more. • Turn body away: z=-2.114, p=.035 • Hearing dogs showed MORE turning body away to stop play. • Differences approached significance for: • Chase me: z=-1.89, p=0.06 • Hearing dogs chased more • Toy play: z=-1.905, z=.06 • Deaf dogs showed MORE solitary toy play.
Deaf dogs have poor social skills! • Play behavior is critical for development of social behavior • Deaf/blind dogs miss out on important give/take interactions • Develop poorer social skills with their cohorts • Suggests that experience is critical for social skill development • Supports data from human children • Suggests that developmental period is critical for social behavior, even in dogs • Supports Udell and Wynne’s 2-step theory • Need biology • Need experience in using biology
And for humans? • Games that young children play may echo simpler forms of play seen in animals • Play = practice for humans as well • Play is a child’s work: helps children learn their place in the social world within which they live.