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A Brief History of Learning Theory What is learning? Definition of learning: Dictionary definition: To gain knowledge, comprehension, or mastery through experience or study. Psychology definition: A relatively permanent change in behavioral potentiality that is not due to maturation or typical physical growth, but is due to (reinforced) practice or experience. Which is better description? Why? Behavioral potentiality: Obviously, must be measurable behavior change But when must behavior occur? Immediately after learning? Within 1 year? Issue of learning vs. performance- is this an important distinction? Must learning result in behavioral change? Define permanent and define behavior Instinct- may emerge at different time periods Importance of critical periods Walking- learned or instinct? Memory issues How much cognition is necessary? Can bacteria learn? Definition of behavior: If a dead man can’t do it……. Definitions of learning? Learning: experience, practice or performance? Reflexes: Are they important for learning? Instincts: imprinting and critical periods Practice vs. Experience Performance as an issue Modified definition of learning: learning is a relatively permanent change in behavior or behavioral potentiality that results from experience and cannot be attributed to temporary body states (e.g., fatigue, altered states of consciousness) Definitions of learning? “Types” of learning: Classical conditioning Instrumental or operant Social learning Latent learning Cognition Learning = survival or our strongest instinct Early history of learning theory Plato: Socrates was his teacher, Aristotle was his student Nativism: Knowledge is inherited and a natural component of the human mind a matter of recollection, and not of learning, observation, or study not empirical, and that it comes from divine insight. Every object in physical world has corresponding abstract idea or form that causes it We experience a “tree” but not “treeness” Rationalism: One gains knowledge by reflecting on the contents of one’s mind: The mind’s eye: gaining insight Turn inward to ponder what is innately available Believes in a soul Reminiscence: recollection of our experience that our soul had in heaven which is beyond heaven Plato’s Cave analogy Early history of Learning Theory Aristotle: Plato’s student Empiricism: Knowledge derived from sensory experiences; was NOT inherited Rationalism: Mind is actively involved in attainment of knowledge- must integrate sensory experiences with own knowledge Nativism: Mind must actively ponder the information provided by the senses to discover the knowledge contained within the information Described in detail the human senses Laws of association: Experience or recall of one object will elicit recall of things Similar to that object (similarity) Opposite that object (contrast) That were once originally experienced with that object (contiguity) Early History of Learning Theories Rene DesCartes: 1596-1650 Gentleman Soldier Knowledge is innate Mind versus body problem Separate laws govern each Only humans have souls (mind) Body has “animal spirits” Two do influence one another Reflex arc: Why important? Showed mechanisms of body Early History of Learning Theories The British Empiricist (including, but not limited to): Thomas Hobbes (1651) John Locke (1690) James Mill (1829) John Stuart Mill (1843) Source of all knowledge was sensory experience People are born knowing nothing Gradually we gather knowledge via experience Tabula rasa or blank slate idea (Locke) Opposite of Kant's Nativism Embraced phenomenalism, rational empiricism, pragmatism Extreme position = Empiricist position Set hypotheses for Associationism: Empiricists first outlined: How old concepts become associated in memory How new concepts are formed Hypothesized a direct correspondence between experience and memory Proposed a 1:1 correspondence between simple sensations and simple ideas experience = sensations memory = ideas idea = form of a sensation Complex ideas: James Mill 2 or more simple sensations repeatedly presented together, product of union may be complex idea once complex idea formed, can also be evoked by process of association from simple sensations or ideas Set hypotheses for Associationism: Thomas Browne (1605-1682): Secondary Principles of association: Attempt to make Mills theory more complete No data yet…just assumptions and hypotheses Several hypotheses The length of time 2 sentences coexist determines the strength of association The liveliness or vividness of sensations also affects strength of association The frequency of pairings: more frequent = stronger association Recency of pairings: more recent = stronger association Freedom from other strong associations Constitutional differences current emotional states momentary state of body individual prior habits Variations on Associationism John Stuart Mill: (1806-1873) Complex associations Most important contribution: The whole is different from the sum of its parts (Wait, didn’t the Gestaltists say this!?!!?) George Berkely: (1685-1753): We can experience only secondary qualities Nothing exists unless it is percevied To be is to be perceived David Hume: (1711-1776): We know nothing for sure about ideas We can be sure of nothing Mind = stream of ideas, memories, imaginings, associations, feelings We experience empirical world only indirectly through our own ideas “Habitual order of ideas” give rise to general concepts like causation Continentalist view: Back to knowledge = innate French: Jean-Jacques Rousseau: 1712-1778 Wrote Emile, or On Education Believed in stages of human development Critical for French revolution and our own formation of the U.S. German: Immanual Kant (1724-1804): Innate categories of thought: Careful analysis of our experiences reveals certain categories of thought Categories included: Causality, unity, totality, reality, existence, necessity, reciprocity, (and 5 more) Mental faculties superimposed over our sensory experiences, providing them with structure and meaning Other Historical influences Thomas Reid: Naïve Realism (1710-1796) What we perceive = naïve realism Mind has powers of its own which strongly influence how we perceive world Faculty of psychology: mixture of nativism, rationalism, empiricism Franz Joseph Gall: Role of Physiology (1758-1828) Faculties housed in specific brain locations Before this assumed the heart held all important information! Phrenology: two lasting effects Led to emerging neuroscience research Belief that faculties become stronger with practice- the mental muscle Other Historical influences Three important scientists/philosophers make an important impact on how we approach learning theory today: Charles Darwin Karl Marx Sigmund Freud What? Why those 3? Darwin: suggests we have common ways in which our bodies and our learning operate. Karl Marx: suggested that people were equal Royalty or upper class were not “smarter” People were people Freud: suggested that our early experiences were critical for forming our later experiences Evolution’s influence on Psychology Charles Darwin (1809-1882): Biological and Behavioral Evolution 1859 book: Origin of Species Argued species originated from other species and eventually become distinct from their ancestors Thus: many animals have common, but very distant, ancestors Evidence from domesticated plants and animals Breeding programs; hybrid plants, purebred dogs, cats, etc. Great similarity in body parts across animals: paws, arms, etc. Embryology: most embryos look HIGHLY similar Fossil records: First “Psychological” Research in Learning Hermann Ebbinghaus (1850-1909) First empirical test of associationist hypotheses used nonsense syllables to avoid prior associations served as own subject measured length of time took to learn, amount remembered after some passage of time Results: Several major findings List length: the greater the list- the greater the time to learn PER item Effects of repetition: over-learning and mastery Effects of time on remembering and forgetting: discovered forgetting curve serial position curve Role of contiguity: more contiguity = greater learning Backwards associations Provided DATA for associationist principles Behaviorism It’s not your Mother’s Skinner! American Behaviorism E.L. Thorndike: (1874-1949): Studied animal behavior and how animals learned to react to consequences. Did not have access to Pavlov’s work John B. Watson (1878-1958) founded the school of psychology known as behaviorism. Psychology should be a science of behavior only. Believed that environment molds behavior By 1920s, behaviorism became dominant force in American psychology B.F. Skinner (1904-1990): Blended Watson and Thorndike’s approaches Heavily influenced by Edwin Guthrie, Clark Hull, Edward Tolman Studied how behavior is shaped by rewards and punishments Principles of learning apply to animals and humans alike Thordike(s) and Guthrie also had profound effects on learning/education Thorndike: began to look at Instrumental Behavior Son of a Methodist Minister Graduate of Harvard, student of and highly influenced by William James Professor at Columbia University, influential in starting the psych program there Animal Intelligence (1911) Rated the intelligence of various animals One of the first contemporary psychologists to examine how animals learned Focus on trial and error learning Did NOT have access to Pavlov’s work. Experimented with cats in a puzzle box Put cats in the box Cats had to figure out how to pull/push/move lever to get out; when out got reward The cats got faster and faster with each trial Thorndike: Law of Efect Law of Effect emerged from this research: When a response is followed by a satisfying state of affairs, that response will increase in frequency. When a response is followed by a non-satisfying state of affairs, that response will decrease in frequency Also studied conditioned reflex University of Chicago PhD. With John Dewey, who’s ideas he rejected STRICT behaviorism: Everything is learned, no affect from biology Started out as an educator; developed his theory of behaviorism Felt that any research should use ONLY observable events: rejecting structualism and gestalt schools Rejected traditional study of “thoughts” and “feelings” Had access to Pavlov’s work (unlike E.L. Thorndike) But felt that this Classical Conditioning could be used in other ways Most famous work: Little Albert Study Demonstrated classical conditioning of the emotion of fear But: got in hot water: Behavioral “eugenics”: believed if he could control environmental variables, could control outcome of any human Had an affair with his grad student Ethics of Little Albert study Pavlov’s Contribution Ivan Pavlov was Son of a Russian Orthodox priest Russian physiologist: Studied salivation 1901: discovered and wrote about classical conditioning Found that his dogs reacted to both his presence and the time of day for feeding/experimentation Wanted a way to study conditioned reflexes systematically Researched this: Measured amount of salivation during baseline: Present food to dogs Measure slobber Then added a predictive stimulus: a Bell Presented the BellFood Measured slobber to see if dogs would begin to slobber to the bell Classical Conditioning Remember the Reflex Arc Reflex is elicited by a stimulus At first, must directly stimulate this reflex But, a predictive stimulus can elict the reflex after many pairing Classical conditioning is learning to react to a predictive stimulus The predictive stimulus predicts the eliciting stimulus The eliciting stimulus elicits the reflex Learn to anticipate the reflex behavior so that it occurs to the predictive stimulus is productive and potentially lifesaving! Classical Conditioning Procedure CS US UR Bell Food CR Slobber with less Digestive enzymes Slobber Why so important to American Behaviorism? In the 1930s and 1940s: Physics is “the” science Move towards laws and strict scientific notation of events and variables Use of equations to describe physical phenomenon Pavlov USED strict notation Used clear labels to identify variables Strict notation system for denoting behavioral events Very “scientific” Thorndike had not access to Pavlov’s work; Watson had some contact, Skinner was a student of Pavlov’s writings Burris Frederick Skinner 1904-1990 Skinner’s influence on modern Behaviorism Skinner studied at Harvard Started out as English major, but was unsuccessful Taught at Minnesota and Indiana University; founded a true Psych department at Indiana just after Harvard started theirs Lifelong friend of Fred Simmons Keller Keller was developing concepts of operant conditioning at Harvard with more of an applied/educational focus Also Nate Schoenfield at Columbia Formed the first “group” of behaviorists Skinner’s influence on modern Behaviorism Behavior of Organisms (1948) Laid out tenants of his operant or instrumental conditioning Focus on contingencies and consequences Again, avoided non-observable events but did not say they didn’t exist, just that they needed to be operationalized as observable to be studied For more information see his books On Verbal Behavior or Beyond Freedom and Dignity- very relevant for today! Utopian society:Walden Two (1948) Several kinds of behaviorism: Methodological Behaviorism: Behaviors as such can be described scientifically without recourse either to internal physiological events or to hypothetical constructs such as thoughts and beliefs Watson was a methodological behaviorist: Objective study of behavior; No mental life or internal states- only internal behavior Thought is merely covert speech. Several kinds of behaviorism: Radical behaviorism: Skinner’s behaviorism Expands behavioral principles to processes within the organism In contrast to methodological behaviorism it is not mechanistic or reductionistic; Hypothetical (mentalistic) internal states NOT considered causes of behavior Phenomena must be observable at least to the individual experiencing them. Teleological Behaviorism: Post-Skinnerian, Purposive behaviorism Highly related to microeconomics Focuses on objective observation as opposed to cognitive processes. Several kinds of behaviorism: Theoretical Behaviorism: Post-Skinnerian, Accepts observable internal states as long as can measure with modern technology Dynamic, but eclectic in choice of theoretical structures, emphasizes parsimony. Biological Behaviorism: Post-Skinnerian, Centered on perceptual and motor modules of behavior Theory of behavior systems. Psychological Behaviorism Centers on human behavior. Many applied techniques such as time-out, token-reinforcement Behavioral explanations of child development, education, abnormal, and clinical areas Commonalities among “Behaviorisms” Emphasis on behavior Classical conditioning: S-R psychology Relatively passive Organism does not have to make a response in order for the consequences to occur Responses are ELICITED Operant conditioning: R-S psychology Emphasis on organism operating on environment Behavior is the result of a contingency on that response: If/Then Operant conditioning: responses are EMITTED Radical Behaviorism Science of behavior = natural science Assumptions include: Animal behavior be studied profitably and compared with human behavior Strong emphasis on the environment as cause of behavior Strong tendency to operationalize behavior Emphasis on operant conditioning, Use of jargon: Make definitions specific and clear Tendency to apply concepts of reinforcement/punishment to philosophy and daily life Emphasis on private experience. Radical Behaviorism Embraces genetic and biological aspects of the organism Assumes that behavior evolves as part of the nature of the organism, Study of behavior is a distinct field of study, but Is compatible with biological and evolutionary approaches to psychology Is a proper part of biology Radical behaviorism does not involve the claim that organisms are tabula rasa, without genetic or physiological endowment. Radical Behaviorism Skinner's work focused on operant conditioning: Again, R-S, not S-R Emphasized schedule of reinforcement as IV; rate of responding as DV Emphasis on outcomes and response rates that include areas of study such as decision making, choice, self-control Myth that organisms are passive receivers of conditioning: rather: Operant behavior is titled operant because it operates on the environment Operant behavior is emitted, not elicited: Animals act on the environment and the environment acts back on them, or The consequence of a behavior can itself be a stimulus; Radical Behaviorism But isn’t radical behaviorism = logical positivism. Skinnerians maintain that Skinner was not a logical positivist and recognized the importance of thought as behavior. Skinner himself noted this in his book About Behaviorism. Philosophically, radical behaviorism is most similar philosophically to American pragmatism. Study behavior because it is observable, predictable, orderly and functional. Skinner’s Behaviorism: 1966 article What is the important event or datum to study in the science of behavior? o The probability of a given behavior to occur at a given time When, where, under what circumstances Experimental analysis deals with probability of responding in terms of frequency or rate of responding. o Specify topography of response in such a way that separate instances of an operant can be counted. o The specification is usually made with the help of an apparatusthe"operandum"-some device that allows the response to be counted Skinner’s Behaviorism: 1966 article Responses defined so that they show a uniformity as the organism moves about in a framework defined by its own anatomy and the immediate environment. o Record changes in rate of response and reinforcer o Examine under different environmental situations o Examine under different rules for delivery of reinforcer o Skinner used “cumulative recorder” , we use computers o Also examine interresponse times, interreinforcer times, slopes, etc. o For example: different patterns of responses under 4 basic reinforcement schedules The Ind.Variable according to Skinner: Task of EAB: discover all the variables of which probability of a response is a function These might include: The stimulus: both as an antecedent and as a consequence Discriminative stimuli: the stimulus control assigned to a particular stimulus Asks how the organism perceives the stimulus, not how the experimenter designed the stimulus to be seen Examine via generalization and discrimination gradients The function of the behavior: How does the response operate on the environment What does it “gain” the subject; what is the reinforcer earned by that response? Does not alter “inner states” but environmental manipulations: Not hunger but food intake Not fear, but aversive stimuli Maturation is a variable The IV according to Skinner: Role of the contingency is important (critical) feature of independent variables in EAB, for example in Shaping Extinction Delay of reinforcement Contingencies involving several stimuli and several consequences Examine organism’s actual behavior under different experimental contingencies Examine where, when, how behavior changes under different stimulus conditions Can begin to build rules or laws of behavior The IV according to Skinner: Relationships among the variables are very important Use real time rather than trial by trial “Free operant”: Within given time period, allow subject to make responses Subject determines when, how often, which responses to make to a given set of stimuli and consequences Subject controls the rate of behavior Allows a behaviorist to determine how IVs interact to alter the DV of behavioral responding The IV according to Skinner: Skinner argues his “theory” is atheoretical Does not rely on preconceived hypotheses Rather- examines behavior and from the patterns observed One determines systematic rules and descriptions of behavior under various contingency conditions In Applied settings, best example of this is functional analysis. Inductive and not Deductive Inductive reasoning= reasoning in which the premises seek to supply strong evidence for (not absolute proof of) the truth of the conclusion. Conclusion of a deductive argument is supposed to be certain Truth of the conclusion of an inductive argument is supposed to be probable, based upon the evidence given. Inductive reasoning = reasoning that derives general principles from (many) specific observations Deductive reasoning = reasoning that hypothesizes general principles and then looks for specific observations to support the hypotheses. What does distinguish Skinner’s approach from more typical approaches? Behavior is not a sign of inner mental or physical activities Not a means to the end, but the end Allows a careful specification of the behavior and the processes by which the behavior occurs Really a “functionalist” approach: What is the FUNCTION of the behavior? What does that behavior get for the organism? What does distinguish Skinner’s approach from more typical approaches? Changes in behavior are studied in and of themselves, and not assumed that they belie some underlying cause Study behavior because behavior is interesting and a legitimate variable that is orderly and occurs for a reason Every behavior has a reason Examine how a set of responses come under the control of a corresponding set of stimuli Use probability of response and changes in probability of responses Skinner argues rate of responding is most basic dimension Not assume behavior is a sign or symptom of inner traits, abilities, processes, etc.- look at many behaviors Not rely on verbal behavior alone What does distinguish Skinner’s approach from more typical approaches? Behavior is examined because behavior is important Behavior is not “adjusting to a situation” or “solving a problem” Examine the topography of the behavior Look at the ABCs:The Antecedents, the Behavior, the Consequences Rise of Behaviorism as a field of study As popularity of research grew, several specialized journals popped up: Journal of The Experimental Analysis of Behavior (JEAB): 1958 Journal of Applied Behavior Analysis (JABA): 1968 Verbal Behavior The Behavior Analyst Division 25 in APA is called Experimental Analysis of Behavior International Association of Behavior Analysis: late 1970’s Several international conferences each year General conference Autism Verbal Behavior Several specialized experimental conferences National conferences in variety of countries Now have one of fastest growing licensed professionals in psychology: BCBA and BCBAc Assumptions of Modern Behaviorism Focus on classical and operant behavior; highly influenced by neuroscience Include internal events as part of an organism’s environment Both external AND internal environments influence behavior But: avoid use intervening variables like cognitivists Instead of saying “memory” study relationship between items recalled and length of time between presentation of stimulus and behavior. Assumptions of Modern Behaviorism Feelings and behavior: Don’t consider feelings as “cause” of behavior, but rather as a behavior in and of themselves. Feelings are REAL behaviors that can be studied Again, look for environmental events that may be causal (internal and external) But: also remember that self reported “feelings” can be unreliable: What you think you feel and why you feel it may causal!’ Thinking = behavior Thinking and talking are BEHAVIORS Language = verbal behavior Thinking = private behavior Assume same rules that govern other behaviors will govern thoughts and feelings Obviously, verbal behavior is MUCH more complex in humans but can be studied in similar ways as any behavior Verbal behavior is a HUGE research area in behaviorism. Behaviorism Today Not Skinner’s behaviorism! Focus on both theoretical and applied areas EAB: focus on developing theories of behavior How do animals learn about contingencies How do animals categorize/organize stimuli How do animals make decisions ABA: focus on application Biggest impact on autism, developmental disabilities Also in education, business, industry Emerging as major force in animal behavior, particularly with domestic and companion animals Learning = Adaptation Learning = Evolutionary behavior? Instinctive knowledge: knowledge obtained through the mechanism of heredity Evidence in many species Flexible, but not learned Two common misconceptions about instinctive knowledge Instincts are not influenced by experience Humans do not possess instinctive knowledge Doctrine of Evolution by Natural Selection Mechanism of inheritance: Observed characteristics of individuals are inherited; that is, offspring tend to resemble their parents more than they resemble other individuals Source of variation: Within a species, individuals differ from another in both their physical structures and behavioral dispositions. Method of selection: Those individuals with characteristics that favor survival in competition with others and in the face of environmental stressors or changes will be more likely to transmit their characteristics to offspring and thus tend to be preserved. Natural Selection: Darwin’s 5 major premises: The members of particular species have characteristics that vary Some of these variable characteristics are passed on from parents to siblings Some of these variable characteristics aid survival Species produce more offspring than survive to become adults Those characteristics that aid survival will become more common across generations, those that impede survival will die out. Remember the time line for these changes: MANY generations For humans, this means thousands of years Learning = Adaptation to environment Learning is an adaptive specialization Adaptation = changes that occur over successive generations as a species adjusts to its niche Adaptation = process of adjustment to circumstances in which an individual lives. Thus: Are evolved as solutions to some of problems of survival Humans use adaptation and learning as evolutionary mechanism We learn to adapt to our ever changing niche Greater flexibility to deal with new situations Those that can adapt…live and pass on their genes! Cultural evolution: Process by which (we humans) adapt to our environment by transmitting acquired knowledge from generation to generation through our teaching and imitation. Chimpanzees, Bonobos and the domestic canine also show evidence of this cultural evolution. Domestication of Dogs Involves both natural and artificial selection Natural Selection: Natural selection developed individuals who more likely tolerant of humans Remain closer in, live with humans Several sub categories Tame domesticated Genetically domesticated but wild (feral) Wild type but tame Interestingly, 75% of world’s dogs are feral Domestication: 100,000 year history of domestication As humans entered more agricultural lifestyle, wolves scavenged food from humans This led to changes in wolf morphology and behavior Reduced fear and aggression in presence of humans = exploitation of more food sources Later, humans began to selectively breed 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 Roundness of features Pointy ears, eyes, snout Rounded eyes, floppy ears, Intense eyes “smiling” Softened eyes http://www.youtube.com/watch?v=1QqsSw5BDA8&feature= related http://www.youtube.com/watch?v=B4Z9dUkbq1g&feature=r elated Compare Wolf to Dog Play Paedomorphosis Wolf pups have much shorter development duration 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 Dimitri Belyaev: 1959 to today (Tut, 1999) 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 changes begin By 42 generations: about 70% meet criteria for domestication elite Farm Fox experiment Interesting physical changes: Note, NOT selected for these traits Physical Trait changes: 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 (see Hare, Alexandra , Kaminski, Brauer, Call & Tomasello, 2010): 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: 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 Note important differences: Dogs Wolves Better at following several human gestures Only good at point/gaze Feral dogs and dogs reared in shelters show same unsocialized behavior as wolves Socialized wolves improve in wolf-human social interactions over unsocialized wolves As get older dogs prefer to be with humans As get older wolves prefer to be with another wolf Are these differences due to domesticity or experience? Proximity to humans = important factor Domestication correlates with proximity to humans Domestication theory does not account for Exposure Effects But: Hard to research: 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: not seem to understand morphology of humans vs. their clothing 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 does not qualitatively change behavior, but has changed quantity and duration of certain behaviors These behaviors must then be reinforced to be maintained. 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 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?