Feb. 21, 2012• How and why do people form emotional bonds?“the landscapes of the human heart” Is this a human-specific process or is it a widely-shared one?• Human-specific abilities on displayo Dora is a “letter-writer” in a country with a moderate rate of illiteracy. Why writeletters? Communication via letter is mostly in support of social relationships Humans maintain relationships with people who are distant in time and place (networks vs. groups) Humans have empathy; we share emotions, we share information• Growth & DevelopmentProgress toward maturity involves changes in physical structure and changes in behavior…..• What is behavior? “the movements that an animal makes”(N. Tinbergen)o Motor ability à behavior• Motor development in humans• Profound changes during the first year of life • Locomotion balance, pivot, stop quickly- New gaits--hop, skip, gallop (why age-specific gaits?)• Upper bodyo throwing & catching (what about climbing?)• Hands individual finger control• Holding a writing/marking instrument is human-specific. Humans have more versatility in hand and figure movements than other primates• The preschool years can very aptly be called the play years. Children spend a lot of time running, chasing, galloping, balancing and climbing. Indoors, they paint, build, string beads, cut with scissors, do simple puzzles and color with crayons.”o Schickendanz et al. 1992 Understanding Children • Trends in motor ability (3-7 years old)• Increase in strength (more muscle, more bone, less fat)• Increase in control, precision, coordination• Play? • Characteristics of playo Short sequences (fragments of motor patterns seen in other contexts)o Repetitiouso Reorderingo Exaggeration (uneconomical)o Rapid alterations of behavioro No obvious immediate benefito Metacommunication (“this is play”)• How do we know that it is play? What is similar in these two species?• Why does play exist?• The costs of playo Time and energy expenditureo Accidental injury or deatho Increased risk of predationo Delay of maturation• “Resources allocated to play cannot be allocated to growth, fat storage, feeding, predator avoidance, or nonplay social behavior” (Fagen 1981)• Play—what is it?...why is it?o Play is a familiar category of behavior that is hard to define and whose existence is hard to explain• Who plays ? which species?which stages of development?• Fagen found that almost all reported examples of play were found in birds and mammals• Immatures play more, adults less (mostly travel, feed & rest)Activity level in feral lowland gorillasPlay is a major category of motor behavior for immature gorillas• What kinds of activities are play?o locomotor play is universal among mammals• “Nunes (1999) described A’uwe-Xvante children running around the Namunkura village not because they are in a hurry, but because their bodies “ask” for movement.” Gosso et al. 2005• Mother-offspring play in two closely-related speciesOther species cannot play this way because they do not have the kind of movement versatility found in chimpanzees and humans• Some categories of play identified in many mammals• Locomotor play• Social play (add social agent)• Object play (add object)—it helps to have manipulative hands • Humans are good at combining object play and social play• What kinds of activities are play in birds and mammals?• Locomotor play• Social play (add social agent)• Object play (add object)• Some proposed benefits of playo Practice for specific motor and cognitive skillso Increase knowledge of the physical and social environmento Bonding and cohesiono Increase flexibility, creativity, innovation• Should humans be defined as the “play” species? Is there anything unusual about play in humans? Do humans play more?Do humans play during more life stages? Do humans use play in ways that are unique?Feb. 23, 2012• PlayPlay is a familiar category of behavior that is hard to define and whose existence is hard to explain• Which species play?• mammals & birds• How do we know it is play?...it “looks” different• incomplete, reordered, repeated, uneconomical, no obvious benefit, play face/posture/vocalization • Categories of play• locomotor, social, object • Costs of play• lost energy, predation, injury, maturation delay• Proposed benefits of play• practice, knowledge, bonding, flexibility• If all mammals play, do some mammals play more?• If immature mammals play more than adult mammals, do some species restrict play to the period of immaturity while other species extend play into adult life?• Are humans a highly playful species? Do they play more and play longer than closely related species? • Should humans be defined as the “play” species? Is there anything unusual about play in humans? Do humans play more?Do humans play during more life stages? Do they use play in ways that are unique?• In studies of mice, domestic cats, sheep & baboons….• “Play does not occur immediately after birth…it appears sometime later” • “After play appears, its rate of expression quickly rises to a peak”• The peak of expression of play is brief compared to the lifespan of the life span of the species. Rate of play falls quickly to zero or near zero”• In studies of mice, domestic cats, sheep & baboons…. play is limited to immature animals.• “I was astounded to find that there appears to be no comprehensive data on rates of human locomotor play from birth to sexual maturity.” (p. 216)• Play in Parakana children Gosso, et al. 2005 “Play in hunter-gatherer society” • “….our basic psychological mechanisms have been shaped in the context of the hunting-gathering way of life…” p. 213• “the large discrepancies that exist between ancestral and modern environments may create psychological problems and reduce the quality of life.” p. 214• “Hunter-gatherer children play. They neither hunt nor gather, they do not build houses and shelters, and they do not cook or clean. In fact, the life of children, at least under 7 years of age, is mostly, if not solely, a playful life….observations of foragers strongly suggest…the human pattern involves allocating a very large part of the day to playing….” p. 240• “One important difference between humans and other mammals is that human children, in the hunter-gatherer