ORIGINAL PAPER

Reputation-like inference in domestic dogs (Canis familiaris)

Shannon M. A. Kundey • Andres De Los Reyes •

Erica Royer • Sabrina Molina • Brittany Monnier •

Rebecca German • Ariel Coshun

Received: 6 August 2010 / Revised: 17 November 2010 / Accepted: 19 November 2010 / Published online: 8 December 2010

� Springer-Verlag 2010

Abstract Humans frequently interact with strangers

absent prior direct experience with their behavior. Some

conjecture that this may have favored evolution of a cog-

nitive system within the hominoid clade or perhaps the

primate order to assign reputations based on third-party

exchanges. However, non-primate species’ acquisition of

skills from experienced individuals, attention to communi-

cative cues, and propensity to infer social rules suggests

reputation inference may be more widespread. We utilized

dogs’ sensitivity to humans’ social and communicative cues

to explore whether dogs evidenced reputation-like inference

for strangers through third-party interactions. Results indi-

cated dogs spontaneously show reputation-like inference

for strangers from indirect exchanges. Further manipula-

tions revealed that dogs continued to evidence this ability

despite reduction of specific components of the observed

interactions, including reduction of visual social cues (i.e.,

face-to-face contact between the participants in the inter-

action) and the nature of the recipient (i.e., living, animate

agent versus living, inanimate self-propelled agent). Dogs

also continued to demonstrate reputation-like inference

when local enhancement was controlled and in a begging

paradigm. However, dogs did not evidence reputation-like

inference when the observed interaction was inadvertent.

Keywords Dog � Canine � Cognition �Vicarious reinforcement

Introduction

Humans regularly interact with strangers, often determin-

ing how to act toward them with little direct experience

with the individual’s behavior (e.g., Seabright 2005). This

feature may have favored evolution of a cognitive system

that assigns reputations (e.g., Subiaul et al. 2008). Such

judgments involve ascribing enduring behavioral disposi-

tions by conjecturing that behaviors are predictable and

consistent over time and contexts. Assessment might

occur directly through first-party interactions or indirectly

through social learning by viewing others’ exchanges

(McGregor and Dabelsteen 1996; Parejo and Aviles 2007;

Subiaul et al. 2008). While direct reputation judgments

likely provide more accurate information (Axelrod 1984;

Alexander 1987; Hauser et al. 2003), indirect reputation

judgments allow behavior prediction when direct interac-

tions might be costly (e.g., assessing strength or domi-

nance; Axelrod 1984, 1987).

Recently, some have posited that non-human species

might also make indirect reputation judgments based on

their performance in a variety of social learning studies.

For example, chimpanzees respond differently to humans

behaving as unwilling versus unable helpers and to humans

that intentionally rather than accidentally fail to give

food, as well as recruit the best collaborators (Call and

Tomasello 1998; Povinelli et al. 1998; Call et al. 2004;

Melis et al. 2006). Such studies suggest chimpanzees infer

a variety of social information through observation. How-

ever, these studies often involved subjects receiving direct

experience with humans or conspecific individuals, as

S. M. A. Kundey (&) � E. Royer � S. Molina � B. Monnier �R. German � A. Coshun

Department of Psychology, Hood College,

401 Rosemont Avenue, Room ROS 27,

Frederick, MD 21701, USA

e-mail: kundey@hood.edu

A. De Los Reyes

Department of Psychology,

University of Maryland at College Park,

College Park, MD 20742, USA

123

Anim Cogn (2011) 14:291–302

DOI 10.1007/s10071-010-0362-5

opposed to indirect observations of interactions between

individuals.

Subiaul et al. (2008) recently evaluated whether chim-

panzees predict others’ future behaviors following both direct

and indirect exchanges. Chimpanzees observed unfamiliar

humans either consistently giving or refusing to give food to a

human recipient. Chimpanzees did not prefer to beg to the

generous donor initially, but some learned this preference and

transferred it to unfamiliar donors after multiple trials. Sub-

sequently, some evidenced preference for the ‘‘generous’’

donor after watching interactions with a conspecific. How-

ever, only some chimpanzees learned a generous-donor

preference in direct exchanges and not all exhibited a gener-

ous-donor preference during later indirect exchanges. Those

that did learn the preference only maintained this preference

for the first half of the indirect trials encountered.

Some indicate that the ability to predict future behavior

based on indirect information may be prevalent within the

hominoid clade or perhaps the primate order (e.g., Sea-

bright 2005; Subiaul et al. 2008). However, non-primate

species’ acquisition of skills (e.g., foraging techniques,

dietary and mating preferences, predator evasion) from

experienced individuals, attention to communicative cues,

and propensity to infer social rules suggests reputation

inference may be more widespread (Bekoff 1995; Herman

et al. 1999; Danchin et al. 2004; Kaminski et al. 2005;

Zentall 2006; Horowitz 2009). Indeed, studies with birds,

dogs, and fish suggest natural selection may favor skills

that function analogously to reputation judgment within

specific domains (e.g., Amy and Leboucher 2007; Brosnan

and de Waal 2003; Bshary and Grutter 2006; Grosenick

et al. 2007; Rooney and Bradshaw 2006).

Prior work suggests that dogs are adept readers of human

social and communicative behavior, as well as highlight

that their cognitive skills sometimes appear more flexible

and like those of humans than those of species more closely

related to humans phylogenetically (e.g., Hare et al. 2002;

Cooper et al. 2003; Hare and Tomasello 2005; Vas et al.

2005; Schwab and Huber 2006; Miklosi and Soproni 2006;

Miklosi et al. 2004; Reid 2009; Topal et al. 2009). Thus, we

capitalized on dogs’ acute sensitivity to humans’ social and

communicative cues to explore their ability for reputation-

like inference from an indirect interaction. Through six

experiments, we queried whether dogs would evidence

reputation-like inference for unfamiliar humans engaged in

third-party interactions, as well as the relative importance of

the components of the interaction.

Experiment 1

Dogs observed two unfamiliar human demonstrators

interacting with a third human (the recipient). One

demonstrator consistently gave food to the recipient

(‘‘giving’’) while the second gave and rescinded food

(‘‘withholding’’). After watching exchanges, dogs chose

from which demonstrator to take a treat (either withholding

or giving). Importantly, dogs were allowed to consume the

treat regardless of which demonstrator they chose (giving

or withholding). As a result, dogs did not receive differ-

ential feedback regarding whether their choice of a par-

ticular demonstrator was correct or incorrect. If dogs made

reputation-like inferences after watching indirect exchan-

ges, we hypothesized they would choose the giving dem-

onstrator more often than the withholding demonstrator.

Method

Subjects

We recruited dogs through personal contacts and fliers. All

were at least one year of age, lacked advanced obedience

training, and free of major health problems. Staff instructed

owners that there were no correct behaviors and reminded

them they were not to help their dog. However, owners

were permitted to give brief commands such as ‘‘stay’’ and

‘‘sit’’.

Ten dogs completed pretraining and the experimental

trials (mean = 3.8 years, SD = 2.9, 5 male). The subjects

included 2 Dachshunds, 1 Shetland Sheepdog, 1 German

Shepherd, 1 terrier, 1 Pit Bull, 1 Labrador Retriever, 1

Beagle, and 2 dogs of mixed breeding. Two dogs were

excluded. One dog was excluded due to failure to make

choices during pretraining while a second was excluded due

to the owner’s pointing. These data were not included in any

analyses.

Apparatus

Tape marked 5 floor locations (Fig. 1). Two marks (0.5 m

apart) indicated areas for demonstrators to sit. We posi-

tioned a ‘‘Treat Line’’ (0.5 m 9 5 cm) in front of the

demonstrators. Either extent was equidistant from the

recipient. A fourth mark (1 m in front of the demonstrators)

designated an area for the recipient to sit (recipient area).

Throughout exchanges, owners positioned their dog in the

observation area, which was located 1 m from the

exchange and oriented such that the dog and owner could

view the exchanges.

Demonstrators offered large dog bones (8 9 2.5 9

1.25 cm) to the human recipient, but smaller commercial

dog treats (* 1.25 cm diameter) to the dog. Throughout

exchanges, demonstrators and the recipient held food in

clear plastic bags. When demonstrators offered the dog a

food treat, the amount of food contained within the bags

was equated.

292 Anim Cogn (2011) 14:291–302

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Procedure

The institution’s Animal Care and Use Committee

approved all procedures for all experiments. Testing

occurred in a laboratory room; owners remained in the

laboratory room throughout the sessions. Upon arrival,

dogs familiarized themselves with their surroundings by

exploring the area while their owner completed forms

regarding the dog’s health, disposition, and training

(10–15 min).

Following acclimation, dogs underwent pretraining to

ensure they would make choices without owner direction

(e.g., pointing). Owners then positioned dogs in the reci-

pient area. The experimenter placed a treat on the Treat

Line’s left or right extent according to a predetermined

order and instructed the owner to allow the dog to take the

treat. After consumption, owners returned their dog to the

recipient area. The experimenter repeated this procedure

until dogs consumed 3 treats from each extent.

After pretraining, owners moved their dog to the

observation area and experimental trials commenced.

The experimenter led the unfamiliar demonstrators into the

room. The demonstrator sat in their assigned location for

that trial and completed 10 alternating exchanges (5 for

each demonstrator) with the human recipient (the experi-

menter). The recipient and demonstrators’ actions varied

according to exchange type: withholding or giving. Each of

the human demonstrators and the human recipient were

female and dressed in casual clothing. Which person

played each role varied across dogs. During the demon-

strations, the demonstrators faced the recipient.

In withholding exchanges, the demonstrator removed a

large treat, gained the dog’s attention (moving the treat or

tapping the treat as needed), made eye contact with the

recipient, placed the treat in front of the recipient on the

Treat Line, and withdrew her hand. Next, the recipient

extended her hand to take the treat. The demonstrator

extended her hand and removed the treat, not allowing the

recipient to take it. Giving exchanges resembled with-

holding exchanges except that the recipient was allowed to

take the treat. The demonstrators and recipient never talked

to each other. For two dogs, the treat was given or

exchanged in the air above the treat line due to the dogs’

expression of excessive excitement when the treat was

placed on the floor. In both giving and withholding

exchanges, the human demonstrators made eye contact

with the human recipient only during the exchange.

Following the set of 10 exchanges, the human recipient

moved away from the experimental area so as not to

influence the dog’s choice. Owners moved their dog to the

recipient area and centered their dog between the demon-

strators before looking straight ahead at a location marked

on the far wall. Dogs remained in front of their owners

throughout the choice process. As the dog watched, the

demonstrators withdrew a small treat and placed it on the

end of the treat line in front of them. The owner then

released their hold of the dog’s leash to allow the dog to

take and consume one treat. Importantly, the human dem-

onstrators and human recipient avoided eye contact with

the dog and owner during the dog’s choice. They also

maintained focus on the wall in front of them until the dog

had made its choice. The dog was allowed to consume one

treat regardless of which demonstrator’s treat was chosen.

The remaining treat was removed immediately after the

dog’s choice. The demonstrators’ positions and identities

were varied across dogs.

Data analysis

We used binomial tests to evaluate dogs’ choices in the

experimental trial. In particular, we evaluated whether dogs

selected the giving demonstrator at a level greater than that

expected by chance (i.e., test value = 0.5). Results were

considered significant only if a\ 0.05. The SPSS statisti-

cal package (Version 16.0, SPSS, Chicago, IL, US) was

used for all statistical tests. Choices were confirmed via

later videotape analysis by two coders.

Results and discussion

All ten dogs that completed pretraining chose the giving

demonstrator’s treat (binomial test: P = 0.002, Fig. 2). This

Fig. 1 Pictorial depiction of Experiment 1 where unfamiliar human

demonstrators interacted with a human recipient in a face-to-face

exchange in a giving (gave treats) or withholding (withheld treats)

manner. Dogs chose a demonstrator from whom to take a treat after

watching 10 exchanges (5 with each demonstrator); we allowed dogs

to consume the treat they chose

Anim Cogn (2011) 14:291–302 293

123

suggested that they evidenced reputation-like inferences for

strangers after viewing third-party interactions. Although

chimpanzees also inferred reputation through indirect

experience, they both had opportunities to acquire and

required extensive prior personal experience with similar

direct exchanges (Subiaul et al. 2008). Importantly, stimulus

enhancement alone cannot account for our results (e.g.,

directing an individual’s attention to a particular place or

object; Thorpe 1956), as the human recipient acted similarly

toward both the giving and withholding demonstrator.

Additionally, the withholding demonstrator had more direct

contact with her demonstration bones than the giving

demonstrator did. Thus, if stimulus enhancement alone

could account for our results, we would expect a prepon-

derance of choices toward the withholding demonstrator.

Following these findings, we were interested in under-

standing the importance of typical interaction components

to dogs’ reputation-like inferences. Specifically, we were

interested in understanding the role of including visual

social cues between the demonstrators and recipient and

the nature of the recipient (i.e., living, animate agent versus

non-living, inanimate self-propelled agent). Thus, we tes-

ted whether dogs would continue to choose a ‘‘giving’’

demonstrator under a variety of conditions. In Experiment

2, we reduced means for meaningful communicative

behavior by preventing face-to-face contact between

demonstrators and the recipient. In Experiment 3, we

removed the human identity (and associated visual social

cues) of the demonstrators by encasing the demonstrators

in boxes for all exchanges and the dog’s choice. In

Experiment 4, we replaced the human recipient with a non-

human, inanimate but self-propelled recipient. In Experi-

ment 5, we replaced the direct giving and withholding of

treats between the human demonstrators and the recipient

with inadvertent consequences for each attempted

exchange. Lastly, in Experiment 6, we explored whether

local cues could account for the findings of Experiment 1,

as well as whether the same results would be evidenced

within a ‘‘begging’’ paradigm. We reasoned that such tests

might reveal possible mechanisms and/or the contexts in

which dogs made reputation-like inferences.

Experiment 2

In Experiment 2, we investigated the importance of face-

to-face contact in dogs’ indirect reputation-like inferences.

Demonstrators sat with their backs toward the recipient and

their head in-line with their body. We reasoned if face-

to-face contact between parties in an observed exchange is

necessary for dogs’ reputation-like inference, then dogs

should choose demonstrators at chance when face-to-face

contact is removed. Alternatively, if face-to-face contact

between parties in observed exchanges is not necessary for

dogs’ reputation-like inference, dogs should show a pref-

erence for the giving demonstrator.

Method

We employed Experiment 1 methods with ten naıve dogs.

However, in Experiment 2, the demonstrators sat with their

backs toward the recipient to prevent face-to-face contact

(Fig. 3a). Thus, the demonstrators reached backwards to

extend treats to (giving demonstrator) and extend/retract

treats from (withholding demonstrator) the human recipient

during exchanges. Following the exchanges, the human

demonstrators reached backwards (facing away from the

dog) to place treats on the Treat Line for the dog to choose

Fig. 2 Percentage of dogs

choosing the giving

demonstrator in each

experiment. In Experiments

1–4, as well as 6a and 6b, dogs

chose the giving demonstrator

significantly more often than the

withholding demonstrator.

Asterisks indicate significance at

a\ 0.05

294 Anim Cogn (2011) 14:291–302

123

from. Choices were confirmed via later videotape analysis

by two coders.

Nine naıve dogs completed pretraining and experimental

trials (mean = 4.1 years, SD = 3.2, 5 male). The subjects

included (as indicated by the owner) 1 Border Collie,

2 Labrador Retrievers, 1 Shiba Inu, 1 Beagle, 1 Cocker

Spaniel, and 3 dogs of mixed breeding. One additional dog

was excluded for failure to acclimate to the laboratory

environment. Data from this subject were not included in

the reported analyses.

Results and discussion

Eight of the nine dogs chose the giving demonstrator’s treat

(binomial test: P = 0.039, Fig. 2). These results suggest

that dogs made inferences regarding demonstrators’ future

behavior absent one component of a meaningful interac-

tion—face-to-face contact. These results suggest face-

to-face contact is not necessary for dogs’ reputation-like

inference. In combination with other data, this might

indicate that the judgments dogs are making are subserved by

a simpler cognitive process such as vicarious reinforce-

ment—a classic social learning process not necessitating the

proposition of a cognitive system for reputation-like infer-

ence. However, it is also possible that dogs relied on a social

cue other than face-to-face contact to make these reputation-

like inferences.

Experiment 3

In Experiment 3, we removed visual social cues in the

observed exchanges between the human demonstrators

and the human recipient. We accomplished this by

encasing demonstrators in large boxes such that the dog

never saw the humans inside. If the visual social cues

emitted by the demonstrators are important to dogs’

reputation-like inferences, dogs should choose the

‘‘withholding’’ and ‘‘giving’’ boxes at chance when we

reduce the demonstrators’ ability to signal such cues.

Alternatively, if social cues emitted by the demonstrators

are not necessary for dogs’ indirect reputation-like infer-

ences, dogs should show a preference for the ‘‘giving’’

box. This outcome would be consistent with the notion

that perhaps dogs are capable of making reputation-like

inferences via a simpler cognitive process such as vicar-

ious reinforcement rather than a more complex cognitive

mechanism (i.e., a more general reputation-like inference

system).

Method

We employed Experiment 1 methods with ten naıve dogs.

However, in Experiment 3, we added two large cardboard

boxes (76 9 76 9 76 cm; one black, one white) to cover

the demonstrators (Fig. 3b). A small hole (4 9 2.5 cm)

Fig. 3 Pictorial depiction of Experiments 2–5. a depicts Experiment

2 where unfamiliar human demonstrators interacted with a human

recipient while facing backwards to prevent face-to-face contact.

b depicts Experiment 3 where human demonstrators encased in boxes

interacted with a human recipient. c depicts Experiment 4 where

human demonstrators interacted with a small moving box. d depicts

Experiment 5 where giving and withholding boxes served as

intermediaries between the human demonstrators and the recipient.

In all experiments, dogs chose a demonstrator from whom to take a

treat after watching 10 exchanges (5 with each demonstrator); we

allowed dogs to consume the treat they chose

Anim Cogn (2011) 14:291–302 295

123

was cut in the center bottom extent of the side facing the

recipient to allow the passage of treats.

Besides the boxes, Experiment 3 trials mirrored those of

Experiment 1. Each box maintained its ‘‘trait’’ across all

trials for a single subject. However, box color was coun-

terbalanced with respect to the displayed trait across sub-

jects, and box position was counterbalanced across trials

for each subject. The large commercial dog bones were

extended and retracted through the boxes’ openings with-

out showing the demonstrators’ hands. To accomplish this,

the demonstrators slid the bones on the floor through the

boxes’ opening. However, approximately the last 1.25 cm

of the bones remained inside the box. This allowed the

withholding demonstrator to retract the bones using her

fingertips without showing her hands. Although dogs could

possibly utilize olfactory cues to determine that humans

were inside the boxes, visual information regarding the

contents of the boxes was not available. Choices were

confirmed via later videotape analysis by two coders.

Ten naıve dogs completed pretraining and experimental

trials (mean = 4.0 years, SD = 4.2, 6 male). The subjects

included 1 Chihuahua, 1 Irish Water Spaniel, 1 Bearded

Collie, 1 Pit Bull, 1 Pug, 1 Beagle, 1 Rottweiler, 1 Cane

Corso, and 2 dogs of mixed breeding. We excluded two

additional dogs due to their expressing fear of the boxes.

These data were not included in the reported analyses.

Results and discussion

Nine of the ten dogs chose the giving demonstrator’s treat

(binomial test: P = 0.021, Fig. 2). These results suggest

that dogs inferred the boxes’ likely future ‘‘behavior’’ even

though we modified the experimental paradigm to reduce

the social cues emitted by the demonstrators. Here, we

reduced the emission of social cues because the human

demonstrators’ bodies were not visible to the dog prior to

or during the experimental trial. Such data are consistent

with the view that a simpler cognitive process such as

vicarious reinforcement rather than a more complicated

reputation inference system could subserve the reputation-

like inferences made by the dogs.

Alternatively, it is possible that dogs chose consistently

based on cues having little to do with the social aspects of

the interactions they observed. For example, perhaps dogs

viewed the demonstrating boxes in Experiment 3 as reli-

able or unreliable machines, much like a human would

view a vending machine that consistently (‘‘giving’’) or

unreliably (‘‘withholding’’) ‘‘worked’’ (i.e., dispensed food

product as instructed). Humans, like dogs, would be more

likely to approach the ‘‘giving’’ machine than the ‘‘with-

holding’’ machine. Thus, it remains possible that dogs may

employ a more complex cognitive reputation-like inference

system in contexts in which social information is relevant.

Experiment 4

In Experiment 4, we evaluated whether dogs would

continue to demonstrate a preference for the giving dem-

onstrator even when we replaced the human agent with a

non-living, inanimate self-propelled object. To accomplish

this, a small moving box served as the recipient. As in

Experiment 1, the recipient (the small moving box) col-

lected or failed to collect treats from the human demon-

strators. If dogs’ inferences require a living, animate agent

to serve as the recipient of the demonstrators’ actions, dogs

should choose the human demonstrators equivalently when

the human recipient is replaced by a non-human, inanimate

self-propelled box. If, however, a living, animate agent is

not necessary as a recipient of the demonstrators’ actions,

dogs should show a preference for the giving demonstrator

even when we replace the human recipient with a non-

human, inanimate self-propelled box.

Method

We employed Experiment 1 methods with ten naıve dogs.

However, in Experiment 4, a small yellow box (24 9

12 9 12 cm) with a recessed top compartment served as

the recipient (Fig. 3c). A toy remote-control car inside

allowed the box to move along a 1-m track. The track

extended from the Treat Line to a ‘‘garage’’ (48 9 24 9

24 cm box), which contained a small front opening. An

experimenter surreptitiously moved the small box along the

track, which enabled it to collect and deposit treats into the

garage.

Experiment 4 experimental trials approximated those of

Experiment 1 with the exception that the moving box

collected treats. During exchanges, the experimenter sur-

reptitiously drove it to the center of the Treat Line where

demonstrators placed treats into a special compartment on

the box’s top. In withholding exchanges, the demonstrator

then extended her hand toward the treat and removed it to

her bag before the box could drive away with the treat.

Giving exchanges resembled withholding exchanges with

the exception that the box drove away with the treat and

deposited it in the garage. After 10 exchanges, the exper-

imenter removed the box, track, and garage to allow the

dog to move to the recipient area. Choices were confirmed

via later videotape analysis by two coders.

Ten naıve dogs successfully completed pretraining

and experimental trials (mean = 3.6, SD = 2.4, 7 male).

The subjects included 1 Beagle, 1 Pug, 1 Boston Terrier,

1 German Shepherd, 1 Dalmatian, 1 terrier, 1 Toy Poodle,

and 3 dogs of mixed breeding. We excluded one dog due to

failure to make choices during pretraining and a second

dog due to fear of the cart. These data were not included in

any analyses.

296 Anim Cogn (2011) 14:291–302

123

Results and discussion

All ten dogs that completed pretraining and experimental

trials chose the giving demonstrator’s treat (binomial test

P = 0.002, Fig. 2). This suggests dogs made inferences

regarding the demonstrators’ future behavior even when

the recipient was a non-living, inanimate self-propelled

object. It appears that a living, animate recipient is not

necessary to dogs’ judgments of the demonstrators’ future

behavior, as dogs continued to demonstrate a preference for

the giving demonstrator even when the recipient was a

small moving box. These data are consistent with the view

that dogs’ judgments are flexible and in some contexts do

not require social interaction. However, one possibility is

that dogs employ a more complex cognitive reputation-like

inference system in other contexts. Additionally, it is

possible that dogs extended agency to the cart recipient in

this experiment due to the self-propelled motion of the cart.

Future research might evaluate this possibility through

demonstrations involving a non-living, inanimate, non-

self-propelled recipient.

Experiment 5

In Experiments 1–4, we queried whether dogs evidenced

reputation-like inference for unfamiliar humans through

third-party interactions, as well as the relative importance

of various components of the interaction. In each experi-

ment, dogs chose the ‘‘giving’’ demonstrator more often

than the ‘‘withholding’’ demonstrator, despite manipula-

tions of the visual social cues emitted by the demonstra-

tors (Experiments 2–3) and the nature of the recipient

(Experiment 4). In all four experiments, the recipient and

demonstrators interacted directly. That is, the demonstra-

tors either directly gave or withheld food from the

recipient.

In Experiment 5, we removed this direct link between

the recipient and the demonstrators. In essence, we repe-

ated Experiment 1. However, instead of directly giving or

withholding treats from the human recipient, the demon-

strators placed their treats into small visually identical

boxes located between the demonstrators and recipient. We

rigged one box to be ‘‘giving’’. When a treat was placed

into the giving box, it slid down a ramp to emerge on the

side facing the recipient. However, we rigged the second

box to withhold treats. When a treat was placed into the

box, it slid down a ramp to emerge on the side facing the

demonstrator where the recipient did not have access to it.

Following the demonstrations, dogs chose from which

human demonstrator to take a treat. Thus, in Experiment 5,

we modified the act of giving and withholding by the

demonstrators to be inadvertent.

Importantly, in this setup, the box intermediaries were

responsible for the ‘‘giving’’ or ‘‘withholding’’ of treats, not

the human demonstrators themselves. If dogs’ inferences

from watching an observed interaction do not require a

direct interaction between the recipient and the demon-

strators, subjects should continue to prefer the giving

demonstrator as in Experiments 1–4.

Method

We employed Experiment 1 methods with twelve naıve

dogs. However, in Experiment 5, we employed two small

white boxes (30 9 20 9 20 cm) as intermediaries between

the human demonstrator and the recipient (Fig. 3d). The

outward appearance of the boxes did not differ visually.

Each box contained a rectangular hole into which treats

could be placed (20 9 6.4 cm). The inside of the ‘‘giving’’

box was arranged such that when the giving demonstrator

placed a treat inside, the treat emerged in front of the

recipient. The inside of the ‘‘withholding’’ box was arran-

ged such that when the withholding demonstrator placed a

treat inside, the treat emerged not in front of the recipient,

but instead in front of the demonstrator who originally

placed it in the box. The giving and withholding boxes

were placed such that the end closest to the demonstrator

was even with the Treat Line. Between trials, we erected a

large curtain (120 9 120 cm) to obscure the dog’s view.

Experiment 5 experimental trials approximated those of

Experiment 1 with the exception that we used the with-

holding and giving boxes as intermediaries between the

‘‘giving’’ and ‘‘withholding’’ demonstrators and the human

recipient. During exchanges, the demonstrators placed their

treats into the box nearest them and withdrew their hand.

As the demonstrators placed their treats into the box, the

recipient reached toward the closest extent of the box into

which the treat was placed. On giving exchanges, the

recipient removed a treat from the giving box. On with-

holding exchanges, the recipient did not remove a treat

from the withholding box. Instead, we rigged the with-

holding box to return the treat to the withholding demon-

strator, who removed the treat from the withholding box.

Thus, whenever the giving demonstrator placed a treat into

a box, the treat emerged in front of the recipient. However,

whenever the withholding demonstrator placed a treat into

a box, the treat was returned to the withholding

demonstrator.

After 10 exchanges, the experimenter allowed the dog to

move to the recipient area. The human demonstrators then

placed treats on the extent of the boxes closest to the dog

before the experimenter directed the owner to allow the

dog to take one of the two treats.

A total of six trials were completed. The dog was

allowed to consume one treat regardless of which

Anim Cogn (2011) 14:291–302 297

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demonstrator’s treat was chosen on each trial. The human

recipient removed the remaining treat. This ensured dogs

did not receive differential feedback regarding whether

their choice of a particular demonstrator was correct or

incorrect. That is, because dogs were reinforced regardless

of the choice they made, there was no reason due to rein-

forcement alone that dogs should choose one demonstrator

over the other across the six trials.

The demonstrators’ positions were counterbalanced

across trials, and the demonstrators always placed their

treat into the box closest to them. However, the outcome of

a particular demonstrator placing a treat into a box

remained constant throughout trials for each dog. For

example, regardless of whether the withholding demon-

strator placed her treat into the box located to the right or

left of the human recipient, the treat always was returned to

her. However, because the boxes were visually identical in

their outward appearance, the outcome of placing the treat

into the box appeared inadvertent. The identity of the

demonstrators, as well as presentation order, was counter-

balanced across dogs.

Choices were confirmed via later videotape analysis by

two coders. Dogs’ first-trial choices were analyzed via a

binomial test and a one-sample t-test (two-tailed). Twelve

naıve dogs successfully completed pretraining and experi-

mental trials (mean = 3.9 years, SD = 3.3, 6 male).

The subjects included 1 Irish Water Spaniel, 1 Schnauzer,

1 Border Collie, 2 German Short-Haired Pointers, 1

Doberman, 2 Great Danes, 1 Standard Poodle, and 3 dogs

of mixed breeding. We excluded four dogs: one that failed

to make choices during pretraining, one that was inatten-

tive during exchanges, and two because their owner poin-

ted during the experimental trials. These data were not

included in any analyses.

Results and discussion

Seven of the twelve dogs that completed pretraining and

experimental trials chose the giving demonstrator’s treat on

the first trial (binomial test: P = 0.774, Fig. 2). Over six

trials, as a group, dogs chose the giving demonstrator on a

mean of 2.75 (SEM = 0.33) trials. Three dogs made 4

choices toward the giving demonstrator, 6 dogs made 3

choices toward the giving demonstrator, and 3 dogs made 1

choice toward the giving demonstrator. Thus, dogs did not

choose the giving demonstrator significantly more often

than chance (one-sample t-test, t(11) = -0.76, P = 0.46;

3 choices for the giving demonstrator). Thus, dogs did not

choose the giving demonstrator significantly more often

than the withholding demonstrator when the ‘‘giving’’ and

‘‘withholding’’ appeared inadvertent. These findings sug-

gest that future research might further examine whether the

method of giving and withholding rewards is a mechanism

by which dogs make reputation-like inferences when

observing human exchanges.

Experiment 6

In Experiments 1–4, dogs chose the ‘‘giving’’ demonstrator

more often than the ‘‘withholding’’ demonstrator despite

manipulations in the visual social cues emitted by the

demonstrators during the interaction and the nature of the

recipient. However, in Experiment 5, dogs did not show a

preference for the giving demonstrator when the giving and

withholding of the demonstrators appeared inadvertent

rather than purposeful.

Given these findings, one might argue that the dogs’

preference for the giving demonstrator in Experiments 1–4

is attributable to a local enhancement effect or that this

preference might not translate into a more ‘‘communica-

tive’’ situation. That is, the dogs in our experiments were

not forced to interact with the human demonstrators

directly (e.g., beg for food). Thus, it might be that in

Experiments 1–4, we evaluated dogs’ learning about the

‘‘possessiveness’’ of the demonstrators rather than more

general reputation-like inferences. Indeed, ‘‘possessive-

ness’’ might be a trait relevant to an individual’s reputation

and likelihood for future action, just as ‘‘giving’’ and

‘‘withholding’’ might be seen as traits relevant to reputation

and likelihood for future action.

In Experiment 6, we tested the notion that the results of

Experiment 1 are attributable to a local enhancement effect

(hereafter, local enhancement control), as well as whether

the results of Experiment 1 might not translate into a more

‘‘communicative’’ situation employing begging as a mea-

sure rather than choice (hereafter, begging measure). In the

local enhancement control, we replicated Experiment 1

with a group of naıve dogs in a situation in which the

human demonstrators switched positions with each other

and the human recipient faced the wall while dogs com-

pleted their choices. In the begging condition, we repli-

cated Experiment 1 with a group of naıve dogs in a larger

space. This enabled us to use begging toward (e.g., sitting

in proximity of, pawing at, jumping on, vocalizing at, etc.)

each of the demonstrators as a measure. In this replication,

the human demonstrators also switched positions with each

other, and the human recipient faced the wall while dogs

completed their choices. We hypothesized dogs would

choose the giving demonstrator significantly more often

than the withholding demonstrator, even when the dem-

onstrators switched positions before the dogs made a

choice in the local enhancement control. Additionally, we

hypothesized that dogs would continue to show a prefer-

ence for the giving demonstrator, as displayed by greater

time begging toward the giving demonstrator, when we

298 Anim Cogn (2011) 14:291–302

123

used begging instead of choice as a measure in the begging

condition.

Method

Local enhancement control

We employed Experiment 1 methods with ten naıve dogs

with several exceptions. Following the exchanges, the

demonstrators switched positions with each other. While

the demonstrators reversed their positions, the human

recipient stood and turned her back toward the human

recipients such that she faced the wall. The owner was then

signaled to move their dog to the recipient area. After the

dog was in position, the demonstrators placed a treat

simultaneously on the treat line, and the dog was allowed

to choose one treat. Choices were confirmed via later

videotape analysis by two coders.

Ten dogs completed pretraining and the experimental

trials (mean = 4.3 years, SD = 3.2, 7 male). The breeds of

the dogs included 2 Chihuahuas, 1 Samoyed, 1 Border

Collie, 1 Terrier, and 5 dogs of mixed breeding. We

excluded one dog due to owner pointing. These data were

not included in any analyses.

Begging measure

We employed Experiment 1 methods with ten naıve dogs.

However, the scale of the experimental area was expanded

to allow for begging to be used as a measure, and no

pretraining was employed. Two chairs were placed 1.73 m

apart for the demonstrators to sit in. A third chair was

centered 1.98 m in front of the demonstrators’ chairs for

the owner to sit in. The owner was instructed to hold onto

their dogs’ leash and to position their dog between their

legs until instructed to let go of the leash.

After the owner and dog were in position, the human

recipient let the human demonstrators into the room. The

human demonstrators moved to sit in their assigned chair

with their hands behind their back concealing the large

demonstration bones used in Experiment 1. The giving

demonstrator began each trial with 4 bones while the

withholding demonstrator began each trial with 2 bones.

This ensured that after the demonstrations, as described

below, the demonstrators each held an equal amount of

bones (2) behind their backs in preparation for the dog’s

choice.

The human recipient then moved from standing beside

the dog/owner to stand beside one of the two demonstra-

tors, with her body facing the dog/owner. She then exten-

ded her hand (palm up) toward the human demonstrator

as the demonstrator extended her hand, with a bone resting

on her palm, to the human recipient. If the human

demonstrator was giving (giving exchange), the bone was

deposited into the human recipient’s palm by the demon-

strator before the giving demonstrator retracted her now

empty hand behind her back. The human recipient then

showed the dog the bone, turned her back to the dog, and

showed the dog that she was placing the bone into her back

pocket. Approximately one-half of the bone remained

visible to the dog while in the recipient’s pocket. After

placing the bone into her back pocket, the human recipient

showed the dog that her hand was now empty before

moving back to stand beside the dog/owner. If, however,

the human demonstrator was withholding (withholding

exchange), the withholding demonstrator retracted her

hand behind her back without depositing the bone into the

human recipient’s palm. The human recipient then showed

the dog her empty hand, turned her back to the dog, and

showed the dog that she was placing her empty hand into

her back pocket. The human recipient then showed the dog

that her hand was still empty before moving back to stand

beside the dog/owner. Next, the human recipient moved

from standing beside the dog/owner to stand beside the

remaining demonstrator. Depending on the identity of the

demonstrator, either a giving or withholding exchange

occurred. In total, the human recipient approached each

demonstrator twice in alternation. The location, identity,

and order in which the giving and withholding demon-

strators were approached varied across dogs. Importantly,

for half of the dogs, the human recipient approached the

giving demonstrator first while for the remaining half, the

withholding demonstrator was approached first. The human

demonstrators were always female and dressed in casual

clothing. Throughout their demonstrations, they looked

straight ahead and avoided eye contact with the dog and

owner.

After the human recipient had approached each dem-

onstrator twice, the human recipient moved from standing

beside the dog/owner to standing centered between the

two demonstrators. She indicated to the demonstrators to

switch positions. As the demonstrators switched positions,

she removed the two bones from her back pocket, held

them in front of her, and turned to face the wall. She then

indicated to the demonstrators to display a bone in their

palm. The height of the bone was consistent between the

demonstrators, but varied according to the dog’s height

and always remained just out of reach of the dog (i.e., for

larger dogs, the bones were held higher than for smaller

dogs). After the demonstrators had their bones in position,

the human recipient indicated to the owner to release their

dog. The dog’s behavior was then recorded for the next

30 s, as the human recipient and demonstrators remained

motionless.

Subsequently, two coders analyzed the resultant video to

determine which demonstrator the dog first approached, as

Anim Cogn (2011) 14:291–302 299

123

well as the number of frames the dog spent begging from

each demonstrator. We considered dogs to display begging

behavior when they were located within arm’s reach

(* 31 cm) of a demonstrator. We used Adobe Premiere

Elements 7.0 software for frame-by-frame coding

(30 frames/s).

Ten dogs completed pretraining and the experimental

trials (mean = 3.2 years, SD = 2.1, 5 male). The subjects

included 1 Pug, 1 Labrador Retriever, 1 Beagle, 1 Amer-

ican Foxhound, 1 Australian Shepherd, 1 Australian Cattle

Dog, 1 Yorkshire Terrier, and 4 dogs of mixed breeding.

One dog was excluded due to owner pointing, a second dog

was excluded due to excessive barking during the trial, and

two dogs were excluded due to owner concerns regarding

the begging measure. These data were not included in any

analyses.

Results

Local enhancement control

All ten dogs that completed both pretraining and experi-

mental trials chose the giving demonstrator’s treat (bino-

mial test: P = 0.002, Fig. 2). Thus, dogs chose the giving

demonstrator significantly more often even when local

enhancement effects are controlled for.

Begging measure

Nine of the ten dogs that completed both pretraining and

experimental trials approached the giving demonstrator

first (binomial test: P = 0.021). Next, we evaluated the

number of frames in which dogs were observed to beg from

the withholding and giving demonstrators. All dogs spent

more time begging from the giving demonstrator than the

withholding demonstrator. The mean number of frames

dogs begged toward the giving demonstrator was 502.10

(SEM = 80.93) frames, whereas the mean number of

frames dogs begged toward the withholding demonstrator

was 51.70 (SEM = 20.22). A paired-samples t-test indi-

cated that dogs spent significantly more time begging

toward the giving demonstrator than the withholding

demonstrator (t(9) = 4.83, P \ 0.0001).

Discussion

In Experiment 6, we performed two manipulations to

address whether the results of Experiment 1 were due to

local enhancement and whether dogs would show a

preference for the giving demonstrator in a more com-

municative situation. The results of the local enhancement

control and begging measure indicated that dogs were not

simply making choices based on a particular location

associated with reward. Additionally, the begging mea-

sure indicated that dogs continued to show a preference

for the giving demonstrator even when we evaluated

begging rather than a choice to take a treat from the

proximity of the giving or withholding demonstrator, as in

Experiment 1.

General discussion

These data suggest dogs can derive and act on information

about unfamiliar individuals through reputation-like

inferences by observing third-party interactions—an abil-

ity previously thought to be exclusive to the hominoid

clade and possibly members of the primate order (e.g.,

Seabright 2005; Subiaul et al. 2008). However, it is

unclear how general their reputation-like inferences might

be, as well as what system might subserve such judgments.

More specifically, Subiaul et al. (2008) distinguish

between reputation inference, ‘‘an abstract social reasoning

skill’’, and ‘‘domain-specific skills that function analo-

gously to reputation judgments’’ (p. 612) such as transitive

inference of relative dominance status among individuals.

According to Subiaul and colleagues, judgments derived

from true reputation inference are used flexibly in novel

circumstances, perhaps even being applied to non-social

agents. From the current experiments, it is unclear

whether dogs’ reputation-like inferences are abstract in the

same way that humans’ are or more domain-bound.

However, the significant number of dogs choosing the

‘‘giving’’ demonstrator, absent differential reinforcement,

across a variety of unfamiliar contexts suggests some

flexibility.

Interestingly, in the current experiments, dogs made

these reputation-like inferences even when visual social

cues were eliminated or reduced (e.g., face-to-face contact

during the interaction) and a living, animate recipient was

replaced with a non-living, inanimate self-propelled reci-

pient. Given dogs’ acute sensitivity to human gestures and

cuing, it remains possible that social cues not tested in

these experiments may account for dogs’ behavior in

reaction to unfamiliar individuals’ displayed traits. How-

ever, the results of Experiments 5 and 6 suggest this is not

the case. In Experiment 5, the human demonstrators,

recipient, and owners were present. If dogs were reading

human gestures and cuing in Experiments 1–4 and such

cueing was leading to significantly more choices to the

giving demonstrator, we would have expected evidence of

this also in Experiment 5. Additionally, we controlled for

possible ‘‘Clever Hans’’ effects in Experiment 6 by having

the human recipient face the wall behind the owner and dog

during the dog’s choice. Even when the human recipient

turned her back to the dog and owner so as not to emit

300 Anim Cogn (2011) 14:291–302

123

possible cues to the dog, dogs continued to show a pref-

erence for the giving over the withholding demonstrator.

It is also possible that dogs extended agency to the

giving and withholding donors even when, for example,

their backs were turned (Experiment 2) or their body was

hidden by a box (Experiment 3). Alternatively, dogs may

have acted following the demonstrations through cues that

had little to do with the social aspects of observed inter-

actions. For example, in Experiment 3, dogs may have

viewed the demonstrating boxes similarly to the way a

human might view a reliable (‘‘giving’’) versus an unreli-

able (‘‘withholding’’) vending machine. Importantly, even

if dogs appeared to evidence reputation-like inferences

through observation in the complete absence of typical

cues indicative of meaningful social interactions, this

would not rule out the possibility that dogs could use such

social cues when they were available. Our results merely

indicate that dogs are also capable of making what appear

to be reputation-like inferences even when such cues are

not available. These findings leave open the possibility that

dogs’ purposive reputation-like inferences may be sub-

served by simpler processes such as vicarious reinforce-

ment in some contexts.

In any event, the findings extend a growing body of

literature on the ability of animals outside the primate order

to make reputation-like inferences and act upon unfamiliar

individuals’ reputations. Future research may benefit from

continued testing of the mechanisms explaining these

effects, as well as their flexibility.

Acknowledgments Author order for the first and second author was

determined by coin toss. The first and second author share equal

authorship credit on this paper. We would like to thank Chelsea

Taglang, Sherry McClurkin, Robin Reutten, Chelsea Wolke, Ayelet

Baruch, Jessica Arbuthnot, Rebecca German, and Meghan Tomlin for

their assistance. We would also like to thank the dogs and dog owners

that participated. The experiments reported comply with all current

laws in the United States. We have no conflicts of interest to report.

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