gestural communication in children and chimpanzees

Gestural Gestural communication in communication in

children and children and chimpanzeeschimpanzees

• Humans communicate with each other in unique ways.Humans communicate with each other in unique ways.

• Most obviously, linguistically, with socially learned, Most obviously, linguistically, with socially learned, intersubjectively shared symbolsintersubjectively shared symbols

• But also gesturally. Many of the most important gestures But also gesturally. Many of the most important gestures humans use - e.g., for greeting or leaving, for threatening or humans use - e.g., for greeting or leaving, for threatening or insulting, for agreeing or disagreeing - are also socially insulting, for agreeing or disagreeing - are also socially learned, intersubjectively shared, symbolic conventions that learned, intersubjectively shared, symbolic conventions that vary across cultures in much the same way as linguistic vary across cultures in much the same way as linguistic symbols.symbols.

• This requires both ‘mindreading’ (theory of mind) and This requires both ‘mindreading’ (theory of mind) and the ability/motivation to cooperate with others.the ability/motivation to cooperate with others.

Tomasello (in press); Tomasello, Carpenter, & Liszkowski (submitted)Tomasello (in press); Tomasello, Carpenter, & Liszkowski (submitted)

OutlineOutline

• DevelopmentDevelopment• Theoretical issuesTheoretical issues• PointingPointing

• Pointing basicsPointing basics• InfantsInfants• ApesApes• Children with autismChildren with autism

Development of communication in infantsDevelopment of communication in infants

MilestoneMilestone Average Age (months)Average Age (months)

Babbling (e.g., bababa)Babbling (e.g., bababa) 77

[?] Joint attention, anticipatory [?] Joint attention, anticipatory smilessmiles

by 8-9by 8-9

Comprehends a wordComprehends a word 99

ShowingShowing 9-109-10

GivingGiving 1212

PointingPointing 1212

Comprehends 50 wordsComprehends 50 words 1313

Produces first wordProduces first word 13 (range 9-16)13 (range 9-16)

Produces 10 wordsProduces 10 words 15 (range 13-19)15 (range 13-19)


Produces word combinationsProduces word combinations 21 (range 18-24)21 (range 18-24)

Adamson (1996); Carpenter, Nagell, & Tomasello (1998)Adamson (1996); Carpenter, Nagell, & Tomasello (1998)

Development of communication in infantsDevelopment of communication in infants

MilestoneMilestone Average Age (months)Average Age (months)

Babbling (e.g., bababa)Babbling (e.g., bababa) 77

[?] Joint attention, anticipatory [?] Joint attention, anticipatory smilessmiles

by 8-9by 8-9

Comprehends a wordComprehends a word 99

ShowingShowing 9-109-10

GivingGiving 1212

Pointing Pointing (ToM, coop., complexity)(ToM, coop., complexity) 1212

Comprehends 50 wordsComprehends 50 words 1313

Produces first wordProduces first word 13 (range 9-16)13 (range 9-16)



Produces word combinationsProduces word combinations 21 (range 18-24)21 (range 18-24)

Adamson (1996); Carpenter, Nagell, & Tomasello (1998)Adamson (1996); Carpenter, Nagell, & Tomasello (1998)

Theoretical debateTheoretical debate• ‘‘Lean’ versus ‘rich’ interpretations of gestures in 12-Lean’ versus ‘rich’ interpretations of gestures in 12-

month-old infants and apesmonth-old infants and apes

• social-cognitive understanding:social-cognitive understanding:• lean: just trying to achieve certain lean: just trying to achieve certain behavioralbehavioral effects in others effects in others

(see others as causal but not mental agents; influence (see others as causal but not mental agents; influence behaviorbehavior) )

• rich: attempting to influence the rich: attempting to influence the intentional/mental statesintentional/mental states of of others (transfer a mental message; influence others (transfer a mental message; influence mindmind))

• motivation: motivation: • lean: to achieve lean: to achieve ownown goals (e.g., get object or attention from goals (e.g., get object or attention from

adult) adult) • rich: rich: also for othersalso for others (inform, help, share); cooperative structure (inform, help, share); cooperative structure


Pointing basicsPointing basics• In itself, pointing is nothing. When faced with a In itself, pointing is nothing. When faced with a

pointing finger, most animals and very young infants pointing finger, most animals and very young infants simply stare at the finger. simply stare at the finger.

• Even understanding the directional nature of pointing Even understanding the directional nature of pointing is not enough to comprehend a full communicative act. is not enough to comprehend a full communicative act. It is possible to follow someone’s point but not know It is possible to follow someone’s point but not know what he means by it. To illustrate: what he means by it. To illustrate:


Tomasello, Call, & Gluckman (1997);Tomasello, Call, & Gluckman (1997);see Call & Tomasello (2005) for a reviewsee Call & Tomasello (2005) for a review

• In a food finding context, a human points to one of two opaque containers.

Apes follow the point - but then choose randomly.

• Why?Why?

• Either apes don’t know Either apes don’t know whatwhat E was directing their E was directing their attention to (exactly what E was referring to), or else attention to (exactly what E was referring to), or else they don’t know they don’t know whywhy E was directing them to it (what E was directing them to it (what E’s motive was).E’s motive was).• whatwhat: precise referent is not bucket as physical object but : precise referent is not bucket as physical object but

bucket as location of foodbucket as location of food• whywhy: not just to show bucket, to inform them of the location: not just to show bucket, to inform them of the location

• Pointing can be incomprehensible without some form of Pointing can be incomprehensible without some form of shared context or ‘common ground.’ To correctly shared context or ‘common ground.’ To correctly identify the referent, the recipient needs to assume the identify the referent, the recipient needs to assume the point is point is relevant torelevant to something she and the pointer something she and the pointer shareshare. .


Importance of shared contextImportance of shared context(what + why)(what + why)

• Shared context can help you determine Shared context can help you determine whatwhat the other is pointing to (and often the other is pointing to (and often whywhy))

• Expressions of attitude can also help you Expressions of attitude can also help you determine determine whywhy..

Attitude Attitude (observable cue to motive – why?)(observable cue to motive – why?)

More pointing basicsMore pointing basics

• A pointer thus combines an act of reference with an A pointer thus combines an act of reference with an expression of motive, with the desire that the expression of motive, with the desire that the recipient attend to both of these, and from this infer recipient attend to both of these, and from this infer the pointer’s overall intention - what the pointer the pointer’s overall intention - what the pointer wants the recipient to do - by finding some relevance wants the recipient to do - by finding some relevance to their common ground. to their common ground. involves understanding of intentions and shared experienceinvolves understanding of intentions and shared experience

• This entire process is inherently This entire process is inherently collaborativecollaborative: : communicator and recipient work together to identify communicator and recipient work together to identify the intended referent, as well as the pointer’s larger the intended referent, as well as the pointer’s larger intention (Clark, 1996). intention (Clark, 1996).

Tomasello (in press); Tomasello, Carpenter, & Liszkowski Tomasello (in press); Tomasello, Carpenter, & Liszkowski (submitted)(submitted)


• Cooperative communicative acts involve an additional Cooperative communicative acts involve an additional type of intention as well: a communicative intention or type of intention as well: a communicative intention or intention about the communication specifically intention about the communication specifically (Grice, (Grice, 1957; Sperber & Wilson, 1986)1957; Sperber & Wilson, 1986)..

• When a person points to a tree for me, she not only wants me When a person points to a tree for me, she not only wants me to notice the tree, she also wants me to notice to notice the tree, she also wants me to notice her desire that I her desire that I notice the treenotice the tree. This additional tier is necessary to instigate in . This additional tier is necessary to instigate in me the kinds of relevance inferences required to identify the me the kinds of relevance inferences required to identify the communicator's reason for communicating (her motive). communicator's reason for communicating (her motive).

• if instead she leans back and I see the tree, I don’t need to make if instead she leans back and I see the tree, I don’t need to make those kinds of inferencesthose kinds of inferences



She intends that I attend to X (and wants us to know this She intends that I attend to X (and wants us to know this together) for some reason relevant to our common together) for some reason relevant to our common ground.ground.



She She intendsintends that I that I attend attend to X (and wants us to know to X (and wants us to know this together) for some reason relevant to our this together) for some reason relevant to our common ground.common ground.

Apes do have some understanding of others intentions Apes do have some understanding of others intentions and attention. Either:and attention. Either:

1)1) do not have a do not have a joint attentional frame (common joint attentional frame (common ground)ground) with the human that enables them to with the human that enables them to determine reference; determine reference; (She’s pointing to the bucket. I’m (She’s pointing to the bucket. I’m searching for the grape – I don’t care about the bucket.)searching for the grape – I don’t care about the bucket.)

2)2) do not understand the do not understand the communicative communicative intentionintention, i.e., that the human wants them to , i.e., that the human wants them to know that she has an intention with respect to know that she has an intention with respect to them; orthem; or

3)3) do not understand the do not understand the informing/helping informing/helping motivemotive (cooperative intention) of the human in (cooperative intention) of the human in this situation.this situation.

Tomasello (in press); Tomasello, Carpenter, & Liszkowski Tomasello (in press); Tomasello, Carpenter, & Liszkowski (submitted)(submitted)

Complexity of pointingComplexity of pointing

Complexity of pointing: Complexity of pointing: AdultAdult examples examples

Standing in line at the bank, one person points for another in the adjacent line to a scarf she has inadvertently dropped on the floor. Gloss: "You dropped that."

On a river bank next to a noisy waterfall, a person hands me a book up (I am on top) for safekeeping as she climbs up. She points to the tip of a pencil protruding from the book. Gloss: "Don't let this fall out".

In a bar, to a bartender, a person simply points to his empty shot glass. Gloss: "I'll have another".

In airplane, I am standing up idly near the bathrooms. A man approaches and points to the bathroom door with a quizzical expression. Gloss: "Are you waiting for the bathroom?"

One person to another in line, informing them of a gap in the line ahead of them. Gloss: "Hey. Move up."

I approach my parked car and a truck has it blocked in. I look to the driver with an apologetic expression and point to my blocked-in car. Gloss: "Sorry, but you have to move to let me out". Tomasello, Carpenter, & Liszkowski (submitted)Tomasello, Carpenter, & Liszkowski (submitted)

Complexity of pointing: Complexity of pointing: InfantInfant examples (11-13 examples (11-13 months)months)

Carpenter et al. (in preparation); Tomasello, Carpenter, & Liszkowski (submitted)Carpenter et al. (in preparation); Tomasello, Carpenter, & Liszkowski (submitted)

As Dad prepares to leave J points to door.

Mom pouring water; J points to his glass to tell her to pour him some.

Mom tells J not to touch her hot teacup; later he points to it and says "No."

Mom asks where J got something. J points out the door, saying “There.”

J watches as Dad arranges Christmas tree; when Grandpa enters room J points to tree and says "Oh!"

J bumps his head. When Mom comes he points to offending object.

Points to sky to sound of airplane out the window (can't see).

After eating points to bathroom anticipating going to wash hands.

Mom is looking for magnet. L points to basket of fruit it is hidden in.

L pulled lamp halfway off wall. Dad comes in, L points to show what happened.

T leads Dad around house by pointing, until they find Mom.

Complexity of infant pointingComplexity of infant pointing

• Many motives, meaningsMany motives, meanings• important because classically infant pointing was important because classically infant pointing was

thought to have only two main functions:thought to have only two main functions:• imperative: to request objectsimperative: to request objects• declarative: to share attention and interest to objects or declarative: to share attention and interest to objects or

eventsevents• ape ‘pointing’ apparently only imperative ape ‘pointing’ apparently only imperative

Complexity of pointing: Infant examples (11-13 Complexity of pointing: Infant examples (11-13 months)months)














• Many motives, meaningsMany motives, meanings• important because classically infant pointing is thought important because classically infant pointing is thought

to have only two main functions:to have only two main functions:• imperative: to request objectsimperative: to request objects• declarative: to share attention and interest to objects or declarative: to share attention and interest to objects or

eventsevents• ape ‘pointing’ only imperative (?)ape ‘pointing’ only imperative (?)

• Absent referentsAbsent referents• important because this is taken to be a hallmark of important because this is taken to be a hallmark of

uniquely human language; also evidence that it is uniquely human language; also evidence that it is communication on a mental levelcommunication on a mental level

Complexity of pointing: Infant examples (11-13 Complexity of pointing: Infant examples (11-13 months)months)














• Many motives, meaningsMany motives, meanings• important because classically infant pointing is thought to important because classically infant pointing is thought to

have only two main functions:have only two main functions:• imperative: to request objectsimperative: to request objects• declarative: to share attention and interest to objects or declarative: to share attention and interest to objects or

eventsevents• ape ‘pointing’ only imperative (?)ape ‘pointing’ only imperative (?)



• Natural observations are interesting but Natural observations are interesting but experiments are needed.experiments are needed.

ExperimentsExperiments

• Common groundCommon ground• Informative (helping) motiveInformative (helping) motive• Absent referentsAbsent referents• Communicative intentionCommunicative intention

Common groundCommon ground

• Infants begin participating in joint attentional Infants begin participating in joint attentional engagement by 9 months engagement by 9 months (more on that tomorrow)(more on that tomorrow)

• By 14 months, they can use joint attentional By 14 months, they can use joint attentional frames/common ground to interpret others’ frames/common ground to interpret others’ points.points.

Behne, Carpenter, & Tomasello (2005)Behne, Carpenter, & Tomasello (2005)

• 14- to 24-month-olds14- to 24-month-olds

• Following a visible Following a visible ‘‘hidinghiding’’ warm-up, E warm-up, E hid a toy in one of two hid a toy in one of two opaque containers.opaque containers.

• E indicated the toyE indicated the toy’’s s location by pointing or location by pointing or gazing at the correct gazing at the correct container.container.

Even the youngest Even the youngest infants chose the infants chose the correct container more correct container more often than chance. often than chance.

0

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14 months 18 months 24 months

Mean

% c

orr

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resp

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ses +

/- S

E

Gaze

Point

Liebal, Behne, Carpenter, & Tomasello (in preparation)Liebal, Behne, Carpenter, & Tomasello (in preparation)

• 18-month-olds18-month-olds

• In each of two In each of two Common GroundCommon Ground conditions, infants participated in conditions, infants participated in a different shared activity a different shared activity (cleaning up or stacking) with an (cleaning up or stacking) with an adult, then that adult pointed adult, then that adult pointed (“There!”) at a target object. (“There!”) at a target object.

• In a third, In a third, No Common GroundNo Common Ground condition, to test whether infants condition, to test whether infants were really using common were really using common ground, infants shared a frame ground, infants shared a frame with one adult and then a with one adult and then a different adult pointed different adult pointed (“There!”).(“There!”).

that adult

pointed

a different adult pointed

Liebal, Behne, Carpenter, & Tomasello (in preparation)Liebal, Behne, Carpenter, & Tomasello (in preparation)

• Even though the adults pointed Even though the adults pointed in exactly the same way in each in exactly the same way in each condition, infants interpreted condition, infants interpreted the point differently depending the point differently depending on the common ground they on the common ground they shared with the adult:shared with the adult:

In the Common Ground In the Common Ground conditions, infants’ responses conditions, infants’ responses were appropriate to the were appropriate to the previous shared activity. previous shared activity.

In the No Common Ground In the No Common Ground condition, they continued the condition, they continued the previous activity less than in previous activity less than in the corresponding Common the corresponding Common Ground condition, instead Ground condition, instead mostly interpreting the new mostly interpreting the new adult’s point as a declarative.adult’s point as a declarative.

Infants used their common Infants used their common ground with ground with specificspecific partners partners to interpret their partners’ to interpret their partners’ gestures.gestures.


• Many motives, meaningsMany motives, meanings• important because classically infant pointing is thought important because classically infant pointing is thought

to have only two main functions:to have only two main functions:• imperativeimperative: to request objects: to request objects• declarativedeclarative: to share attention and interest to objects or : to share attention and interest to objects or

eventsevents

• Infants do point imperatively and declaratively (more on Infants do point imperatively and declaratively (more on this tomorrow). They also point to this tomorrow). They also point to informinform others of things others of things they do not know.they do not know.

Liszkowski, Carpenter, Striano, & Tomasello (2006)Liszkowski, Carpenter, Striano, & Tomasello (2006)

• 12- and 18-month-olds 12- and 18-month-olds

• Infants watched E Infants watched E repeat an action repeat an action (e.g., (e.g., punching holes)punching holes) with a with a target object.target object.

• The target and a The target and a distractor object were distractor object were displaced.displaced.

• E began looking around.E began looking around.

Infants pointed to Infants pointed to inform the adultinform the adult about about the location of the object the location of the object she was looking for.she was looking for.

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

12 months 18 months

Pro

port

ion

of tr

ials

with

poi

ntTarget Distractor


• Common groundCommon ground

• Many motives, meanings, including to inform Many motives, meanings, including to inform others.others.



Liszkowski, Carpenter, & Tomasello (submitted)Liszkowski, Carpenter, & Tomasello (submitted)

• 12-month-olds12-month-olds• A puppet appeared; E A puppet appeared; E

attended and emoted attended and emoted (positively or neutrally) (positively or neutrally) either to it or to the blank either to it or to the blank screen on the other side. screen on the other side. After the puppet After the puppet disappeared, E turned to disappeared, E turned to the infant.the infant.

In the first phase, infants In the first phase, infants pointed more often when E pointed more often when E attended to the screen attended to the screen than to the puppet (to than to the puppet (to inform).inform).

Infants also pointed when Infants also pointed when the referent was absent, the referent was absent, differentially depending on differentially depending on how E had reacted before.how E had reacted before.

Referent Present Phase

Referent Absent Phase

Attend Event Attend Screen


• Common groundCommon ground

• Many motives, meanings, including to inform Many motives, meanings, including to inform others.others.

• Absent referentsAbsent referents

• Understanding of communicative intention Understanding of communicative intention (tree (tree example)example)

Behne, Carpenter, & Tomasello (2005):Behne, Carpenter, & Tomasello (2005): control condition control condition

• E ‘pointed’ or gazed E ‘pointed’ or gazed to the correct to the correct container but in a container but in a distracted, non-distracted, non-communicative communicative manner.manner.

In this condition, In this condition, children performed at children performed at chance levels.chance levels.

Theoretical debateTheoretical debate• ‘‘Lean’ versus ‘rich’ interpretations of gestures in 12-Lean’ versus ‘rich’ interpretations of gestures in 12-

month-old infants and apesmonth-old infants and apes

• social-cognitive understanding:social-cognitive understanding:• lean: just trying to achieve certain lean: just trying to achieve certain behavioralbehavioral effects in others effects in others

(see others as causal but not mental agents; influence (see others as causal but not mental agents; influence behaviorbehavior) )

• rich: attempting to influence the rich: attempting to influence the intentional/mental statesintentional/mental states of of others (transfer a mental message; influence others (transfer a mental message; influence mindmind))

• motivation: motivation: • lean: to achieve own goals (e.g., get object or attention from lean: to achieve own goals (e.g., get object or attention from

adult) adult) • rich: also for others (inform, help, share); cooperative structurerich: also for others (inform, help, share); cooperative structure


InfantsInfants Communication on mental instead of behavioral Communication on mental instead of behavioral

level level • Evidence Evidence (already reviewed)(already reviewed) of understanding of of understanding of

attention and intentions by 12 monthsattention and intentions by 12 months• Absent referents Absent referents (Liszkowski et al., submitted)(Liszkowski et al., submitted)• MisunderstandingsMisunderstandings

• Shwe & Markman (1997):Shwe & Markman (1997): when 2 when 2½-year-olds request ½-year-olds request something from an adult, and the adult misunderstands something from an adult, and the adult misunderstands but gives them what they wanted anyway, they still but gives them what they wanted anyway, they still attempt to correct the misunderstanding. This suggests attempt to correct the misunderstanding. This suggests that they had that they had bothboth the goal of getting the object and the the goal of getting the object and the goal of having the adult understand their message or goal of having the adult understand their message or communicative intention.communicative intention.

Prosocial motivations Prosocial motivations • to achieve own goals, of course, but also prosocial: to to achieve own goals, of course, but also prosocial: to

inform (help), to share. inform (help), to share.

ApesApes

Communication on mental or behavioral level Communication on mental or behavioral level ??• Evidence Evidence (already reviewed)(already reviewed) of understanding of of understanding of

perception and goals - but not attention and perception and goals - but not attention and intentions intentions (?)(?)

• not much (if any) gesturing about absent not much (if any) gesturing about absent referents in non-language-trained apesreferents in non-language-trained apes

No prosocial motivations No prosocial motivations

• to achieve own goals only; no evidence of to achieve own goals only; no evidence of

gesturing to inform (help others, without benefit gesturing to inform (help others, without benefit for themselves) or share for themselves) or share (tomorrow).(tomorrow).

Children with autismChildren with autism Communication on mental or behavioral level Communication on mental or behavioral level

??• Evidence Evidence (already reviewed)(already reviewed) of understanding of of understanding of

perception and goalsperception and goals - but not attention and - but not attention and intentionsintentions (?) (?)

• ??

No prosocial motivations No prosocial motivations • probably to achieve own goals only; no evidence probably to achieve own goals only; no evidence

of gesturing to share (no studies on informing).of gesturing to share (no studies on informing).

• Also general difficulties with communicative Also general difficulties with communicative intentions intentions (e.g., common ground, ‘language of the eyes’; (e.g., common ground, ‘language of the eyes’; see see Sabbagh, 1999, for a review).Sabbagh, 1999, for a review).

SummarySummary

• By 12 months, when they first begin pointing, By 12 months, when they first begin pointing, infants already show the basics of uniquely infants already show the basics of uniquely human communication, supporting the ‘rich’ human communication, supporting the ‘rich’ view.view.• Support for the social-pragmatic view of language Support for the social-pragmatic view of language

acquisition (Bruner, Tomasello, etc.)acquisition (Bruner, Tomasello, etc.)

• More studies are needed, but so far, ‘leaner’ More studies are needed, but so far, ‘leaner’ interpretations of communication in apes and interpretations of communication in apes and children with autism fit best.children with autism fit best.

Hare and Tomasello (2004) hid food in one of two buckets and then, in one Hare and Tomasello (2004) hid food in one of two buckets and then, in one condition, pointed to the bucket containing the food in order to inform the ape where it was. condition, pointed to the bucket containing the food in order to inform the ape where it was. In this case, as in previous studies, the apes searched randomly. The novelty was in the In this case, as in previous studies, the apes searched randomly. The novelty was in the second condition. Here E began by establishing with each ape a competitive relationship second condition. Here E began by establishing with each ape a competitive relationship over the food, and then later reached toward one of the two buckets in a vain attempt to over the food, and then later reached toward one of the two buckets in a vain attempt to open it (the reaching was impeded). Now, surprisingly, even though the superficial behavior open it (the reaching was impeded). Now, surprisingly, even though the superficial behavior of the human was highly similar to that in the pointing condition - in both cases the human of the human was highly similar to that in the pointing condition - in both cases the human stretched out his arm toward the correct location - the apes in this condition suddenly knew stretched out his arm toward the correct location - the apes in this condition suddenly knew where the food was. In this case, the apes had to discern the goal of the human - to get into where the food was. In this case, the apes had to discern the goal of the human - to get into that bucket - and then infer why he wanted to do this: because there is something good that bucket - and then infer why he wanted to do this: because there is something good inside. This cognitive process is quite complex on its own terms, but the key point is that it inside. This cognitive process is quite complex on its own terms, but the key point is that it includes includes nonenone of the crucial elements of shared intentionality from our analysis of the of the crucial elements of shared intentionality from our analysis of the interpersonal structure of pointing. The apes' understanding of the human's reaching is of interpersonal structure of pointing. The apes' understanding of the human's reaching is of individual goals or intentions toward things, not communicative goals or intentions toward individual goals or intentions toward things, not communicative goals or intentions toward themselves. There is thus no question of a joint attentional frame or common ground, or of themselves. There is thus no question of a joint attentional frame or common ground, or of communicative or referential intentions, or of any assumptions of helpfulness or other communicative or referential intentions, or of any assumptions of helpfulness or other interpersonal motives. interpersonal motives.

Following Tomasello et al. (2005), we may thus attempt to characterize the Following Tomasello et al. (2005), we may thus attempt to characterize the essential elements in the comprehension and expression of human pointing as a essential elements in the comprehension and expression of human pointing as a communicative act by viewing them from the perspective of shared intentionality. Whereas communicative act by viewing them from the perspective of shared intentionality. Whereas apes' understanding of the goal of a reaching person is essentially an act of individual apes' understanding of the goal of a reaching person is essentially an act of individual cognition, humans' understanding that others are pointing out things for them because of cognition, humans' understanding that others are pointing out things for them because of their presumed relevance to some common ground or joint attentional frame is an act of their presumed relevance to some common ground or joint attentional frame is an act of interpersonal cognition involving shared attention and knowledge, along with some motive interpersonal cognition involving shared attention and knowledge, along with some motive

for helping or sharing with others.for helping or sharing with others.

Infants pass this test.

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Point

Infants

Chimpanzees

gestural communication in children and chimpanzees

Documents

produces word combinations

development of communication

autism slide

pointing pointing basics

month old infants

press tomasello

important gestures humans

joint attention