9.916 Communication and TeachingToday’s Lecture Other’s actions are more than spatiotemporal patterns; they reflect, and predict, internal states Predict future actions Theory of Mind Learn new facts and skills Communication & TeachingCommunication & Teaching X&*X&*ReferenceFacts skillsEncoding DecodingX&*X&*X&*Message channelSample EvidenceStandard Model:Ammendment (1):X&*X&*X&*Figure by MIT OpenCourseWare.Communication & Teaching X&*X&*ReferenceFacts skillsEncoding DecodingX&*X&*Message channelArbitrarySignalBehaviourForm = FunctionStandard Model:Ammendment (2):X&*X&*Figure by MIT OpenCourseWare.Communication & Teaching For the teacher/communicator: In Common: Audience-design Distinct: • Exploit learning mechanisms • Exploit perceptual sensitivities • Immediate cost • Immediate benefit • Motive: altruistic donation • Motive: manipulation or long-term benefits Required reading, Sperber & Wilson 1986 SignalX&*X&*X&*X&*Figures by MIT OpenCourseWare.Communication & Teaching For the learner/communicatee: In Common: Attention to new facts / skills Faster / more efficient / more accurate learning Distinct: • Inference about intent • Inference(?) about reality • Context-sensitive • Relatively involuntary(?) Required reading, Sperber & Wilson 1986 SignalX&*X&*X&*X&*Figures by MIT OpenCourseWare.Communication & Teaching • Primate alarm calls (specific predators, but not for informing receiver) • Primate affiliative calls -grunts & girneys (?) Prototypical examples Required reading, Sperber & Wilson 1986, Silk 2000 SignalX&*X&*X&*X&*Figures by MIT OpenCourseWare.Pedagogical Sampling Lack of evidence = evidence of lack Teachers: - expert (i.e. basically correct) - helpful (i.e. provide approximately ideal evidence) Learner Teacher If you can point to two more daxes, you can have a sticker. Here are two more daxes. Xu & Tenenbaum 2007 Figures removed due to copyright restriction.Pedagogical Sampling Lack of evidence = evidence of lack Teachers: - expert (i.e. basically correct) - helpful (i.e. provide approximately ideal evidence) Learner Teacher If you can point to two more daxes, you can have a sticker. Here are two more daxes. Xu & Tenenbaum 2007 Courtesy of Wiley-Blackwell. Used with permission. Figures removed due to copyright restriction.Communication & Teaching For the learner/communicatee: In Common: Attention to new facts / skills Faster / more efficient / more accurate learning Distinct: • Inference about intent • Inference(?) about reality • Context-sensitive • Relatively involuntary(?) • Generic information • Local / episodic information Required reading, Sperber & Wilson 1986 SignalX&*X&*X&*X&*Figures by MIT OpenCourseWare.What’s missing?• “Telling” vs “Teaching” • Generic information?Is human teaching unique?0111223234567TimeRunning speed (mm/s)LeaderFollowerAB3FNLeadbetter et al 2006Ant tandem runningexpertnoviceTeaching:- Increases learning efficiency or content- Local cost to teacher - Only in the presence of a learnerCourtesy Elsevier, Inc., http://www.sciencedirect.com. Used with permission. young. Prey is killed by the motherin front of the cubs. Later, when thecubs begin accompanying her onhunting trips, the mother releasesprey in front of them, which thecubs attempt to catch, sometimesat the cost of losing the preyaltogether [6]. The cubs’ predatoryskills improve over this period,although it remains to be shownthat this results directly from suchpractice (the same applies ina study on domestic cats [7]). Otherpotential cases of teaching involvechimpanzees learning to use stonehammers and anvils, and ospreysteaching their offspring to snatchfish from the water [4,5], but as yetthese rely only upon weakanecdotal evidence.In contrast, Franks andRichardson’s [8] well-controlledstudy on tandem-runningTemnothorax ants was carried outin a laboratory. The intimateinteraction between leader andfollower in a pair of tandemlyrunning ants at first sight bears allthe hallmarks of a parent teachinga child to ride a bicycle. Anexperienced ant will lead individualnaı¨ve nest mates to newlydiscovered food sources or nestingsites, stopping if the follower losesregular antennal contact [9]. Whenthe pair becomes separated, asoccurs when the follower makeslooping movements possiblysearching for landmarks, the leaderremains still, only continuingtowards the food when the followerhas completed her exploratorycircuit (Figure 1). Franks andRichardson [8] demonstrate thatthere are clear two-wayinteractions between thetandem-running ants. When thegap between them becomes toolarge, and antennal contactbetween the pair is lost, the leaderslows down and the followeraccelerates to catch up. Thisbidirectional feedback loopappears to maximise the speed atwhich the two can progress, whileallowing the follower to memorisethe path and its surroundinglandmark features.Such tandem-running meetsmost of the criteria for teaching setout in the definition given by Caroand Hauser [4]. When alone, theleader does not incorporate thefrequent pauses which are used bythe follower to perform orientationloops. Hence the leader’sbehaviour is clearly modified in thepresence of a naı¨ve observer.Leaders incur a time cost: whenan experienced forager is notleading a follower, she travelsfaster to the food source anddoes not stop en route [8]. Asa result, the follower (pupil) findsthe target more quickly than shewould do if searching for it alone.While it appears likely thatfollowers learn route-specificinformation duringtandem-running, it remains tobe shown empirically preciselywhat information is obtained.Franks and Richardson[8] refineCaro and Hauser’s [4] workingdefinition of teaching byintroducing an additional criterion:that feedback from the learner tothe experienced individual mustbe demonstrated. Suchfeedback clearly distinguishestandem-running from other formsof signalling in ants, such asscent-marking food sources, orreleasing alarm pheromones inthe presence of nest intruders [9].In these cases, both the signaland the response are largelyhard-wired; and there is no needto assume that learnt informationhas been transmitted, nor is therea need to invoke learning toexplain the receiver’s response.Most simple forms of signalling,such as use of pheromones, do notappear to meet several criteria laidout by Caro and Hauser’s teachingdefinition: such signals aredisplayed irrespective of thepresence of a naı¨ve receiver, anddo not