ArticlePDF Available

Domestic cats ( Felis catus ) discriminate their names from other words

Authors:

Abstract and Figures

Two of the most common nonhuman animals that interact with humans are domestic dogs (Canis familiaris) and cats (Felis catus). In contrast to dogs, the ability of domestic cats to communicate with humans has not been explored thoroughly. We used a habituation-dishabituation method to investigate whether domestic cats could discriminate human utterances, which consisted of cats’ own names, general nouns, and other cohabiting cats’ names. Cats from ordinary households and from a ‘cat café’ participated in the experiments. Among cats from ordinary households, cats habituated to the serial presentation of four different general nouns or four names of cohabiting cats showed a significant rebound in response to the subsequent presentation of their own names; these cats discriminated their own names from general nouns even when unfamiliar persons uttered them. These results indicate that cats are able to discriminate their own names from other words. There was no difference in discrimination of their own names from general nouns between cats from the cat café and household cats, but café cats did not discriminate their own names from other cohabiting cats’ names. We conclude that cats can discriminate the content of human utterances based on phonemic differences.
This content is subject to copyright. Terms and conditions apply.
1
SCIENTIFIC REPORTS | (2019) 9:5394 | https://doi.org/10.1038/s41598-019-40616-4
www.nature.com/scientificreports
Domestic cats (Felis catus)
discriminate their names from
other words
Atsuko Saito1,2,3, Kazutaka Shinozuka4, Yuki Ito1 & Toshikazu Hasegawa1
Two of the most common nonhuman animals that interact with humans are domestic dogs (Canis
familiaris) and cats (Felis catus). In contrast to dogs, the ability of domestic cats to communicate
with humans has not been explored thoroughly. We used a habituation-dishabituation method to
investigate whether domestic cats could discriminate human utterances, which consisted of cats’ own
names, general nouns, and other cohabiting cats’ names. Cats from ordinary households and from a
‘cat café’ participated in the experiments. Among cats from ordinary households, cats habituated to the
serial presentation of four dierent general nouns or four names of cohabiting cats showed a signicant
rebound in response to the subsequent presentation of their own names; these cats discriminated their
own names from general nouns even when unfamiliar persons uttered them. These results indicate
that cats are able to discriminate their own names from other words. There was no dierence in
discrimination of their own names from general nouns between cats from the cat café and household
cats, but café cats did not discriminate their own names from other cohabiting cats’ names. We
conclude that cats can discriminate the content of human utterances based on phonemic dierences.
Domestic cats (Felis catus) and dogs (Canis familiaris) are the most popular companion animals; worldwide, over
600 million cats live with humans1, and in some countries their number equals or exceeds the number of dogs
(e.g., Japan: dogs: 8,920,000, cats: 9,526,000)2,3. Cats started to cohabit with humans about 9,500 years ago4; their
history of cohabitation with humans is shorter than that of dogs5, and they have been domesticated by natural
selection, not by articial selection68. Despite these dierences in their process of domestication compared to
that of dogs, cats too have developed behaviours related to communication with humans; for example, for human
listeners, the vocalisations of domestic cats are more comfortable than those of African wild cats (Felis silvestris
lybica)9. In addition, purring has dierent acoustical components during solicitation of foods than at other times,
and humans perceive such solicitation purrs as more urgent and unpleasant than non-solicitation purrs10. ese
facts clearly indicate that domestic cats have developed the ability to communicate with humans and frequently
do so; Bradshaw8 suggested that this inter-species communicative ability is descended from intra-species com-
municative ability.
Researchers have only recently begun to investigate cats’ ability to communicate with humans. Miklósi et
al. showed that cats are able to use the human pointing gesture as a cue to nd hidden food, similarly to dogs11.
e researchers also suggested that cats do not gaze toward humans when they cannot access food, unlike dogs.
However, a recent study revealed that cats show social referencing behaviour (gazing at human face) when
exposed to a potentially frightening object, and to some extent cats changed their behaviour depending on the
facial expression of their owner (positive or negative)12. Cats in food begging situations can also discriminate the
attentional states of humans who look at and call to them13. In addition, Galvan and Vonk demonstrated that cats
were modestly sensitive to their owners emotions14, and other research has indicated that cats’ behaviour is inu-
enced by human mood15,16. Further, cats can discriminate their owner’s voice from a stranger’s17. is research
evidence illustrates that domestic cats have the ability to recognize human gestural, facial, and vocal cues.
1Department of Cognitive and Behavioral Science, Graduate School of Arts and Sciences, the University of Tokyo,
3-8-1 Komaba, Meguro-ku, Tokyo, Japan. 2Department of Childhood Education, Musashino University, 1-1-20
Shinmachi, Nishitokyo-shi, Tokyo, Japan. 3Department of Psychology, Faculty of Human Sciences, Sophia University,
7-1 Kioicho, Chiyoda-ku, Tokyo, Japan. 4RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, Japan. Atsuko
Saito and Kazutaka Shinozuka contributed equally. Correspondence and requests for materials should be addressed
to A.S. (email: atsaito@sophia.ac.jp)
Received: 21 June 2016
Accepted: 20 February 2019
Published online: 04 April 2019
Corrected: Author Correction
OPEN
Content courtesy of Springer Nature, terms of use apply. Rights reserved
2
SCIENTIFIC REPORTS | (2019) 9:5394 | https://doi.org/10.1038/s41598-019-40616-4
www.nature.com/scientificreports
www.nature.com/scientificreports/
In contrast to cats, numerous research studies have shown the ability of domestic dogs to communicate with
humans. Dogs are skilful at reading human communicative gestures, such as pointing (reviewed in Miklósi &
Soproni18). Dogs can dierentiate human attentional states1922 and distinguish human smiling faces from blank
expressions23. ey are also capable of using some human emotional expressions to help them nd hidden food
and fetch objects24,25.
Although the majority of prior studies have focused on visual communication between humans and dogs26,
some studies have investigated the dog’s ability to respond to human vocalisations. For example, the pitch of a
human voice aects dog behaviour27: dogs obey high-pitched voices to a greater extent than low-pitched voices.
Dogs can discriminate expressions of emotion with voice28, and obey a command with angry voice more slowly
than with happy voice. Dogs trained to sit and come in response to tape-recorded commands change their perfor-
mance when the phonemes of commands are changed29. Many dog owners believe their dogs understand about
30 utterances30. Extensively trained dogs are able to dierentiate 200–1000 human words or labels31,32. e ability
to understand human verbal utterances is also shown in other species, such as apes33, dolphins34, and parrots35;
however, whether such an ability exists in domestic cats remains untested.
In the present study, we investigated the ability of domestic cats to discriminate human verbal utterances. Cats
are sensitive to dierences in human voice characteristics17. Some owners insist that their cats can recognize their
own names and words related to food. erefore, we can make the following hypothesis: cats can discriminate
words uttered by humans from other words—especially their own names, because a cat’s name is a salient stim-
ulus as it may be the human utterance most frequently heard by domestic cats (cats kept by humans) and may be
associated with rewards, such as food, petting, and play.
We conducted experiments in cats’ homes, using a habituation-dishabituation method, as in our previous
study17. In general, dogs’ ability to recognize human utterances are tested using command and retrieval tasks31,36.
ese tasks require pre-training, and the training of cats to perform on command would require a lot of eort
and time. On the other hand, habituation-dishabituation method enabled us to measure cats’ natural reactions
during a single visit, without extensive training. To test the hypothesis, we presented four dierent words serially
as habituation stimuli, then presented the cats’ own names as test stimuli. If the cats were habituated to the other
4 words and dishabituated to their own names, a rebound response to the presentation of their own names would
be observed, indicating the ability to discriminate their own names from other words.
We conducted four experiments to test the hypothesis. In Experiment 1, we investigated whether cats can dis-
criminate their own names from general nouns with the same length and accents as their own names. If cats can
discriminate their own names from other words by using phonetic characteristics other than length of or accent
of stimuli, cats habituated to the other 4 words should show dishabituation when hearing their own names. e
test cats were living either with no other cats or with a small number of other cats. In this experiment, although
we equalized the familiarity of the nouns, the relative familiarity of names and other nouns was markedly dif-
ferent, that is, cats heard their own names more frequently than other nouns. erefore, cats discriminated their
own names depending both on phonetic characteristics and on familiarity. In Experiment 2, we investigated cats’
ability to discriminate their own names from other cats’ names, by using cats living with 4 or more other cats. It
can be assumed that the test cats were exposed to the other cats’ names as well as their own names; stimuli were
prepared using cohabiting cats’ names. en, in Experiment 3, we examined eects of multiple-cat living envi-
ronments on discrimination of general nouns and cats’ own names, similar to Experiment 1. In Experiments 2
and 3, we tested cats both from ordinary households and from a ‘cat café’, a business establishment where visitors
can freely interact with cats. In Experiments 1 to 3, stimuli used cats’ owners’ own voices, because they exhibit a
marked response to their owner’s voice17. However, this leaves open the possibility that cats can discriminate their
own names only when their owners utter them. us, in Experiment 4, we tested whether cats can discriminate
their own names from general nouns even when unfamiliar persons utter them; if they showed discrimination
ability in this experiment, we would take them to recognize their own names based on common phonetic char-
acteristics in human verbal utterances.
Results
Behaviour score. e upper panels of Fig.1 summarise the cats’ responses to the stimuli, as scored by the
experimenter. rough all the experiments, more than half of the cats responded to voice stimuli by moving
their ears and heads; fewer than 10% of the cats demonstrated vocalisation, tail movement, and displacement.
is trend did not dier contingent on whether stimuli were nouns, other cats’ names, or tested cats’ own names.
Fisher’s exact test revealed that number of cats which showed orienting response (moving ear and/or moving
head) were signicantly higher than which showed communicative response (vocalization and/or tail movement)
in all trials from Experiment 1 to 4 (Supplementary TableS1).
e total scores (Fig.1 lower panels) were moderately correlated with the average response magnitude eval-
uated by the raters, as shown in the next section (Spearman’s rank correlation, ρ = 0.70, P < 0.001; ρ = 0.61,
P < 0.001; ρ = 0.64, P < 0.001, ρ = 0.60, P < 0.001 for Experiments 1, 2, 3, and 4, respectively). us, the raters
evaluations of the response magnitudes might have partly depended on the number of simultaneously occurring
responses by the cats.
Response magnitude. In Experiment 1, the raters’ evaluations revealed that eleven out of the 16 test cats
decreased their average response magnitude from noun 1 to noun 4. ese cats were considered to have suc-
cessfully habituated to the general nouns vocalised by the owners. en, nine out of the eleven habituated cats
increased their response magnitude from noun 4 to their own name. Group-level analysis using a generalized
linear mixed model (GLMM) revealed a signicant eect of stimulus category (F(1,10) = 11.18, P = 0.007),
indicating eleven habituated cats signicantly increased in response magnitude from noun 4 to their own name
(t(10) = 3.34, P = 0.007, Fig.2a). us, habituated cats dishabituated when they heard their own names.
Content courtesy of Springer Nature, terms of use apply. Rights reserved
3
SCIENTIFIC REPORTS | (2019) 9:5394 | https://doi.org/10.1038/s41598-019-40616-4
www.nature.com/scientificreports
www.nature.com/scientificreports/
In Experiment 2, 15 out of the 34 test cats decreased average response magnitude from name 1 to name 4, and
were considered to have successfully habituated to stimuli consisting of the names of other cohabiting cats. e
ratio of successfully habituated cats was dierent between the ordinary households and the cat café (ordinary
households: 6 out of 24, cat café: 9 out of 10; χ2 = 9.60, df = 1, P = 0.002). Although the ratio of successfully habit-
uated cats from ordinary households is very low, we analysed the data from these six cats because of methodolog-
ical restriction. We added housing environment (ordinary households or cat café) as a xed eect for group-level
analysis. GLMM revealed a signicant eect of interaction (stimulus category * environment; F(1,13) = 8.26,
P = 0.013). All six habituated cats from ordinary households increased their response magnitudes from name
Figure 1. Response style to vocal stimuli in overall cats. Upper panels: Behaviour observed in response to voice
stimuli and the percentage of cats that expressed each behaviour in (a) Experiment 1, (b) Experiment 2, (c)
Experiment 3, and (d) Experiment 4. Black solid lines indicate orienting response. Black dashed lines indicate
communicative response. Gray solid lines indicate displacement. Lower panels: Mean total behavioural scores
for all cats in (a) Experiment 1, (b) Experiment 2, (c) Experiment 3, and (d) Experiment 4. Error bars indicate
SEs.
Figure 2. Mean magnitude of responses to each voice in habituated cats in (a) Experiment 1, (b) Experiment
2, (c) Experiment 3, and (d) Experiment 4. Error bars indicate SEs. Asterisks indicate signicant dierences
(P < 0.05).
Content courtesy of Springer Nature, terms of use apply. Rights reserved
4
SCIENTIFIC REPORTS | (2019) 9:5394 | https://doi.org/10.1038/s41598-019-40616-4
www.nature.com/scientificreports
www.nature.com/scientificreports/
4 to their own names. Post-hoc analysis revealed that response magnitudes to stimuli for cats’ own names were
signicantly higher than those for name 4 in these six habituated cats (t(13) = 3.43, P = 0.005, Fig.2b). In con-
trast, only three out of nine habituated cats from the cat café increased their response magnitudes from name 4 to
their own name. e response magnitudes to cats’ own names did not dier from those to name 4 in these nine
habituated cats (t(13) = 0.35, P = 0.732, Fig.2b). Signicantly higher response was also seen in household cats
compared to café cats in response to own name (t (20.24) = 2.39, P = 0.027), but not in response to noun 4 (t
(20.24) = 0.38, P = 0.705, Fig.2b).
In Experiment 3, following the results of Experiment 2, we again included the environment as a xed eect.
Fourteen out of the 20 household cats decreased average response magnitude from noun 1 to noun 4. Seven out
of nine café cats decreased average response magnitude from noun 1 to noun 4. ese cats were considered to
have successfully habituated to the stimuli consisting of spoken nouns. In contrast to Experiment 2, interaction
of stimulus category * environment was not signicant (F (1,19) = 1.52, P = 0.233). A nal model only included
the eect of stimulus category (F (1,20) = 6.05, P = 0.023). irteen out of the 21 habituated cats increased their
response magnitude from noun 4 to their own name. e response magnitude to cats’ own names was signif-
icantly higher from that to noun 4 in these 21 habituated cats (t(20) = 2.46, P = 0.023, Fig.2c). us, these
habituated cats dishabituated when they heard their own names.
In Experiment 4, the raters’ evaluations revealed that 20 out of the 33 test cats decreased their average response
magnitude from noun 1 to noun 4; these cats were considered to have successfully habituated to the general nouns
vocalised by unfamiliar persons. en, 13 out of the 20 habituated cats increased their response magnitude from
noun 4 to their own name. Group-level analysis revealed a signicant eect of stimulus category in twenty habit-
uated cats (F(1,19) = 4.41, P = 0.049), who dishabituated signicantly when they heard their own name uttered
by an unfamiliar person as compared to noun 4 (t(19) = 2.10, P = 0.049, Fig.2d).
We also analysed habituated cats’ sum of behaviour score (total score) to test whether number of responses
simultaneously elicited in response to a vocal stimulus increased from trial 4 (noun or other cats name) to trial
5 (test cat’s name). However, unlike response magnitude, signicant increase in the total score was not observed
except for Experiment 2 (Supplementary Fig.S1). is result suggests that qualitative analysis of behaviour with
present/absent manner is less sensitive to detect dishabituation. It is conrmed that eectiveness of quantitative
analysis with the response magnitude coded by blind raters.
Discussion
In Experiments 1, 3, and 4, cats that habituated to general nouns with the same length and accent as their own
names dishabituated to their own names. is was true both when their owner’s voice was presented (Experiments
1 and 3) and when the unfamiliar person’s voice was presented (Experiment 4), in spite of the fact that cats distin-
guish owners’ voices from unfamiliar persons’ voices17. ese results show that cats can identify their own names
from other words that consisted of the same number of mora but with dierent phonemes when they are uttered
both by familiar person and by unfamiliar person. e results of Experiment 2 suggest that cats from ordinary
households discriminate their own names from those of cohabiting cats but that cats from a cat café may not.
From the results of all experiments, it thus appears that at least cats living in ordinary households can distinguish
their own names from general words and names of other cats. is is the rst experimental evidence showing cats’
ability to understand human verbal utterances.
How can we explain this ability and behaviour on the part of the cats? eir own names must be one of the
most-heard human utterances by cats. If they have no meaning, frequently experienced stimuli should be habitu-
ated and not elicit reaction from cats. However, the results of our experiment were to the contrary; thus, the asso-
ciation between hearing their names and receiving rewards or punishments might aect the behaviour of cats.
is implies that cats’ names can be associated with rewards, such as food, petting, and play, or with punishments,
such as taking them to a veterinary clinic or to a bath. Sometimes, owners who keep multiple cats will call all of
their cats’ names at the same time. In that situation, a cat may associate both its own name and those of cohabiting
cats with reward. ese situations could explain the results of Experiment 2: the ratio of ordinary household cats
that successfully habituated to names of other cohabiting cats was very low (6 out of 24). ere is a possibility
that cats housed with other multiple cats may associate other cats’ names with rewarding or unpleasant events.
However, in some situations, for example, when the owner wishes to take it to a veterinary clinic, or to pet a cat,
they may call only one cat’s name. Taking them to clinic should be a stressor. Petting could be rewarding to the
cat37, although depending on the cats’ personality, it could also be a stressor38. ese situations would facilitate a
cat’s learning to discriminate its own name from those of other cats.
If cats associate their own name with rewards or stressors, it is reasonable to think that they react to their
name. In these experiments, cats responded to owner vocalisation not with communicative behaviour (vocal-
isation and tail moving)39 but just with orienting behaviour (ear moving and head moving)40. is tendency
replicated that reported in our previous study17. is may be caused by the dierence between the situation where
we conducted the experiments and the natural situation. In normal reward or stress situations, name calling by
owners may elicit more dynamic, or communicative reaction from cats.
Next, we consider the results from the cat café. e café cats did not discriminate their own names from the
names of cohabiting cats, though their performance in the discrimination of their own names from general nouns
did not dier from that of ordinary household cats. e social environment may explain this dierence in results.
Many dierent humans visit cat cafés, and since the cats’ names are listed in cafés, visitors can call the names of
the cats. However, the way names are called may vary by visitor (e.g., intonation may vary); such a condition may
hinder cats in discriminating their name from those of other cats. Or, café cats may hear their name mentioned
along with other cat names frequently without accurate reward discrimination by visitors. For example, if a visitor
calls cat A, but cat B approaches to the visitor and cat B gets petting and treats instead of cat A. ese situations
would make name discrimination less relevant for these cats. Additionally, the number of cohabiting cats may
Content courtesy of Springer Nature, terms of use apply. Rights reserved
5
SCIENTIFIC REPORTS | (2019) 9:5394 | https://doi.org/10.1038/s41598-019-40616-4
www.nature.com/scientificreports
www.nature.com/scientificreports/
have aected the results. Usually, the number of cats in a cat café is greater than the number in an ordinary house-
hold. Further, because we conducted the experiment in only one cat café, we cannot assure their generalisability
or reach a denitive conclusion.
Nevertheless, this study has demonstrated that cats can discriminate human utterances based on phonemic
dierences. Although such discrimination is acquired without explicit discrimination training, instead emerging
from the patterns of natural daily communication between humans and cats, we may utilise this ability positively
for cats’ quality of life. For example, perhaps we can get cats to learn that dangerous objects or places are referred
to by specic utterances. is work has shed new light on the ability of cats to communicate with humans; further
clarifying cats’ abilities with respect to cat–human communication will potentially enhance the welfare of both
humans and cats.
Methods
Subjects. In Experiment 1, the participants were 16 domestic cats (8 males and 8 females; age range: 1–11
years, mean age: 3.69 years, SD = 3.01) living with 11 families (three male and eight female owners), each of whom
lived with 2 or fewer other cats. By breed, there were 12 mongrels, two Scottish Folds, an American Shorthair, and
a Himalayan. Fieen of the cats had begun to live with their owner within one year of birth, and one cat when it
was 5 years old. Fieen of the cats were neutered (one female was not).
In Experiment 2, 34 domestic cats (16 males and 18 females) each of which was living with 4 or more other
cats, participated. Twenty-four cats were owned by four families and the remaining 10 were part of a ‘cat café, a
business establishment where visitors can freely interact with cats. e cats had six female owners (two owners
were members of the same household). Of the 34 cats, there were 24 mongrels, three LaPerms, a Devon Rex, a
Somali, a Scottish Fold, an American Curl, a LaPerm Shorthair, a Tonkinese, and a Munchkin. eir ages ranged
from 0.5 to 10 years (mean age: 5.51 years, SD = 2.95), and the ages when they began to live with their owners
ranged from birth to 36 months aer birth. All cats were neutered.
In Experiment 3, participants were 29 domestic cats (16 males and 13 females) living with 4 or more other
cats. ey were kept by three families and one cat café, which had four female owners; of the 29 cats, 9 were from
the cat café. Breeds were 21 mongrels, three LaPerms, a Scottish Fold, an American Curl, a LaPerm Shorthair,
a Tonkinese, and a Munchkin. eir ages ranged from 1 to 11 years (mean age: 6.48 years, SD = 3.29). e ages
when they began to live with their owners ranged from birth to 36 months aer birth. All cats were neutered. Of
these 29 cats, 26 cats participated in Experiment 2. Interval between Experiment 2 and 3 was at least 2 weeks.
In Experiment 4, participants were 33 domestic cats (14 males and 19 females) living with from 0 to 5 other
cats. Of them, 30 cats were kept in 21 families (2 male and 19 female owners) and 3 cats were kept in univer-
sity laboratories. Of the 33 cats, 24 were mongrels, two LaPerms, two American Shorthair, a Scottish Fold, a
Himalayan, a Russian Blue, a Norwegian Forest Cat, and a Bengal. eir ages ranged from 1 to 17 years (mean
age: 6.48 years, SD = 4.14), and the ages when they began to live with their owners ranged from one month
to 36 months aer birth. All cats were neutered, excepting one female. Of these 33 cats, 3 had participated in
Experiment 1 and 5 had participated in Experiments 2 and 3. Experiment 4 was conducted about 3 years aer
Experiment 3. In all experiments, all cats were indoor only except one, and cats were not subjected to food dep-
rivation during the study period. Detailed information is presented in the electronic Supplementary Material
(TablesS2–S5).
Apparatus and Stimuli. Before the experiments began, for each cat, ve sound stimuli consisting of human
voice were recorded. One stimulus consisted of a human calling the cat’s name. e other four stimuli consisted of
a human vocalising four dierent general nouns (Experiments 1, 3, and 4) or four names of other cats living with
the test cats (Experiment 2). For Experiments 1, 2, and 3, the stimuli were recorded by the owners of the tested
cats. For Experiment 4, the stimuli were recorded by two women unfamiliar to the tested cats. Each owner was
instructed to vocalise the cat’s names as he/she normally would; if the owner usually called the cat by a nickname
instead of its real name, the nickname was used. In Experiments 1, 3, and 4, four dierent general Japanese nouns
were selected from the list of Matsumoto41; all nouns had the same level of familiarity and were emotionally neu-
tral. e numbers of moras and accents in the nouns were the same as in the cats name. Speakers were instructed
to vocalise the nouns with the same intonation and manner as they vocalised the cats’ names. In Experiment 2,
four of the other cohabiting cats’ names were recorded similarly to the test cats’ names. e orders of presentation
of general nouns and cohabiting cats’ names were pseudo-randomized.
We recorded the vocalisations with a handheld digital audio recorder (ZOOM H2 Handy Recorder) in WAV
format; the sampling rate was 44100 Hz with 16-bit quantisation. e sound stimuli were adjusted to the same
volume level using sound editing soware (Adobe Soundbooth CS4 or Adobe Audition CS6). During the exper-
iment, the handheld recorder was used to present the stimuli through a speaker (Sony SRS-Z100), which was
hidden from the test cat. e distance between the test cat and the speaker was about 3 m, and the volume of
the voices was approximately 65 dB at 3 m from the speaker. A video camera (Sanyo DNX-CA9 or Panasonic
HX-WA20) placed in front of the test cats recorded their reactions during the playback of the stimuli.
For Experiment 1, 3, and 4, the discriminant analysis was performed to conrm that there was no implicit
dierence in acoustic characteristics between noun and name stimuli. Vocal stimuli for cats which showed dis-
habituation (habituated cats with increasing response magnitude from noun 4 to own name: N = 9, 13, and 13
in Experiment 1, 3, and 4, respectively) were selected for analysis. Six acoustic parameters were extracted from
each vocal stimulus by using Praat 6.0.43 soware: total duration (sec), mean pitch (Hz), f1 (Hz), f2 (Hz), f3
(Hz), and mean intensity (dB). en the discriminant analysis was applied with IBM SPSS Statistics 21. Above
acoustic parameters were set as independent variables, and type of stimulus (noun or name) was set as a group.
As a result of the analysis, high values of Wilks lambda were obtained (Experiment 1, Wilks lambda = 0.930,
χ2 = 2.884, df = 6, P = 0.823; Experiment 3, Wilks lambda = 0.821, χ2 = 11.866, df = 6, P = 0.065; Experiment 4,
Content courtesy of Springer Nature, terms of use apply. Rights reserved
6
SCIENTIFIC REPORTS | (2019) 9:5394 | https://doi.org/10.1038/s41598-019-40616-4
www.nature.com/scientificreports
www.nature.com/scientificreports/
Wilks lambda = 0.979, χ2 = 1.294, df = 6, P = 0.972), indicating that it was dicult to discriminate between noun
and name stimuli by using implicit acoustical characteristics as a cue.
Procedure. Experiments 1, 2, and 3 were conducted from December 2012 to November 2013; Experiment
4 was conducted from September 2016 to April 2017. All experiments were held in each owner’s home or in the
cat café, wherever the particular cats lived. e experimenter waited until cats were calm before beginning the
experiment. During the experiment, the owners were out of their cat’s sight. We used a habituation-dishabituation
procedure in which prepared stimuli were played serially with a 15-s inter-stimulus interval (ISI); the order of
presentation was word 1, word 2, word 3, word 4, and test cat’s name. e number of habituation stimuli and the
ISI were improved versions of those used in a previous study17. Cats’ responses to the stimuli were expected to
decrease during the presentation of words 1 through 4 due to habituation; then, if the cats could discriminate
their own names from the other words, responses were expected to increase again when their own names were
presented, due to dishabituation. e experiment lasted around 1.5 minutes. During presentation, the test cat
was not actively isolated from cohabiting cats, to keep the test cats behaviour natural. ere was no need for any
interruption in the experimental sessions due to cohabiting cats’ behaviour.
All procedures related to animal care and experimentation in our research adhered to the ‘Guidelines for
the treatment of animals in behavioural research and teaching’ as published by the Association for the Study
of Animal Behaviour in Animal Behaviour 71, 245–253 (2006) and to the ethical guidelines of the University
of Tokyo. e study was approved by the Animal Experiments Committee of the Graduate School of Arts and
Sciences of the University of Tokyo and by the Animal Experiments Committee of Musashino University.
Behavioural analysis. Video-recordings of cats’ responses were trimmed to show from 5 s before stimulus
onset to 10 s aer stimulus oset, using Adobe Premiere CS6. Vocalisation of the words and cats’ names in the
clips was masked by pure tones to facilitate blind evaluation of the clips. In total, 80, 170, 145, and 165 clips were
created for Experiments 1, 2, 3, and 4, respectively.
We conducted two kinds of analyses to investigate the cats’ response styles and magnitudes, as in our previous
study17. e rst analysis describes response style. One of the experimenters (KS) observed the clips of each cat
in random order and classied the cat’s responses to the stimuli into ve categories: ear moving, head moving,
vocalising, tail moving, and displacement; each category is described in Table1. ese categories cover orienting
responses (ear moving and head moving)40 and communicative responses (vocalising and tail moving)39. Each
category was scored separately as 0 (absent) or 1 (present) for each clip, to determine the proportion of cats show-
ing each response in each presentation trial. en, the summed score was calculated as the total score for each
clip, to enable examination of the correlation between the numbers of categories occurring simultaneously and
response magnitude rated by blind raters (described in the next section). To check for reliability, the other exper-
imenter (AS) observed a random selection of one-fourth of the clips and scored the cats’ behaviours. e indices
of concordance were 0.75 for ear moving, 0.81 for head moving, 0.99 for vocalising, 0.97 for tail moving, and 0.99
for displacement (κ = 0.76, P < 0.001 for overall observation).
e second analysis was conducted to examine response magnitude. Raters who were blind to the stimuli and
their presentation order scored each cat’s responses in the clips, which were presented in random order within
each test cat. In Experiment 1, there were ten blind raters (6 men and 4 women; mean age = 21.7 years), whereas
in Experiment 2 and 3 there were six blind raters (all women; mean age = 27.5 years), and in Experiment 4, nine
blind raters (one man and 8 women; mean age = 22.9 years). e raters were instructed to compare each cats
behaviours before and aer the presentation of each stimulus and rate the magnitude of the cats responses to the
stimuli from 0 (no response) to 3 (marked response). Kendall’s coecient of concordance showed signicant,
moderate concordance among the raters (W = 0.73, df = 79, P < 0.001; W = 0.73, df = 169, P < 0.001; W = 0.65,
df = 144, P < 0.001, W = 0.55, df = 164, P < 0.001 for Experiments 1, 2 3, and 4, respectively).
Mean response magnitude was calculated for each video clip and used for subsequent analysis. GLMM was
applied using the lme4 package version 1.1–13 on R soware version 3.4.1. Stimulus category (Experiment
1; noun 4 v. own name, Experiment 2; other cat’s name 4 v. own name, Experiment 3; noun 4 v. own name,
Experiment 4; noun 4 v. own name) was set as a xed eect. Environment (ordinary households v. cat café) and
interaction of stimulus category * environment were also set as xed eects for Experiments 2 and 3. Subjects
were set as a random eect. Gaussian distribution with identity link function was specied for lmer function.
en, post-hoc analysis was conducted using the step function in the lmerTest package version 2.0–33; the step
function reduced non-signicant xed eects and determined a nal model. e random eect (subjects) was
manually kept regardless of signicance, to control pseudo-replication.
Data Availability
e data supporting this article are included in Supplementary Electronic Information.
Category Description
Ear moving Any change in ear(s) angle from ear root
Head moving Any change in head angle at the neck
Vocalising Any vocalisation
Tail moving Any movement of tail between its root and tip
Displacement More than one step of displacement of both
hind paws in any direction
Table 1. Descriptions of categories for behavioural scores.
Content courtesy of Springer Nature, terms of use apply. Rights reserved
7
SCIENTIFIC REPORTS | (2019) 9:5394 | https://doi.org/10.1038/s41598-019-40616-4
www.nature.com/scientificreports
www.nature.com/scientificreports/
References
1. Driscoll, C. A., Clutton-Broc, J., itchener, A. C. & O’Brien, S. J. e taming of the cat: Genetic and archaeological ndings hint that
wildcats became housecats earlier—and in a dierent place—than previously thought. Sci. Am. 300, 68–75, https://doi.org/10.1038/
scienticamerican0609-68 (2009).
2. Ferdman, . A. & Ingraham, C. Where cats are more popular than dogs in the U.S.—and all over the world. Washington Post, https://
www.washingtonpost.com/news/won/wp/2014/07/28/where-cats-are-more-popular-than-dogs-in-the-u-s-and-all-over-the-
world (2014).
3. Japan Pet Food Association. e breeding rate and number of breeding of dogs and cats. Japan Pet Food Association, http://www.
petfood.or.jp/data/chart2017/3.pdf (2017).
4. Vigne, J. D., Guilaine, J., Debue, ., Haye, L. & Gerard, P. Early taming of the cat in Cyprus. Science 304, 259, https://doi.org/10.1126/
science.1095335 (2004).
5. Clutton-Broc, J. Origins of the dog: Domestication and early history in e domestic dog: Its evolution, behaviour, and interactions
with people (ed. Serpell, J. A.) 7–20 (Cambridge University Press, 1995).
6. Clutton-Broc, J. e British Museum Book of Cats (British Museum Publications Ltd., 1988).
7. Driscoll, C. A., Macdonald, D. W. & O’Brien, S. J. From wild animals to domestic pets, an evolutionary view of domestication. Proc.
Natl. Acad. Sci. USA 106, 9971–9978, https://doi.org/10.1073/pnas.0901586106 (2009).
8. Bradshaw, J. W. S. Sociality in cats: A comparative review. J. Vet. Behav. 11, 113–124, https://doi.org/10.1016/j.jveb.2015.09.004
(2016).
9. Nicastro, N. Perceptual and acoustic evidence for species-level dierences in meow vocalizations by domestic cats (Felis catus) and
African wild cats (Felis silvestris lybica). J. Comp. Psychol. 118, 287–296 (2004).
10. McComb, ., Taylor, A. M., Wilson, C. & Charlton, B. D. e cry embedded within the purr. Curr. Biol. 19, 507–508, https://doi.
org/10.1016/j.cub.2009.05.033 (2009).
11. Milósi, Á., Pongrácz, P., Laatos, G., Topál, J. & Csányi, V. A comparative study of the use of visual communicative signals in
interactions between dogs (Canis familiari s) and humans and cats (Felis catus) and humans. J. Comp. Psychol. 119, 179–186, https://
doi.org/10.1037/0735-7036.119.2.179 (2005).
12. Merola, I., Lazzaroni, M., Marshall-Pescini, S. & Prato-Previde, E. Social referencing and cat-human communication. Anim. Cogn.
18, 639–648, https://doi.org/10.1007/s10071-014-0832-2 (2015).
13. Ito, Y., Watanabe, A., Taagi, S., Arahori, M. & Saito, A. Cats beg for food from the human who loos at and calls to them: Ability to
understand humans’ attentional states. Psychologia 59, 112–120, https://doi.org/10.2117/psysoc.2016.112 (2016).
14. Galvan, M. & Von, J. Man’s other best friend: domestic cats (F. silvestris catus) and their discrimination of human emotion cues.
Anim. Cogn. 19, 193–205, https://doi.org/10.1007/s10071-015-0927-4 (2016).
15. ieger, G. & Turner, D. C. How depressive moods aect the behavior of singly living persons toward their cats. Anthrozoös 12,
224–233, https://doi.org/10.2752/089279399787000066 (1999).
16. Turner, D. C. & ieger, G. Singly living people and their cats: a study of human mood and subsequent behavior. Anthrozoös 14,
38–46, https://doi.org/10.2752/089279301786999652 (2001).
17. Saito, A. & Shinozua, . Vocal recognition of owners by domestic cats (Felis catus). Anim. Cogn. 16, 685–690, https://doi.
org/10.1007/s10071-013-0620-4 (2013).
18. Milósi, Á. & Soproni, . A comparative analysis of animals’ understanding of the human pointing gesture. Anim. Cogn. 9, 81–93,
https://doi.org/10.1007/s10071-005-0008-1 (2006).
19. Call, J., Brauer, J., aminsi, J. & Tomasello, M. Domestic dogs (Canis familiaris) are sensitive to the attentional state of humans. J.
Comp. Psychol. 117, 257–263 (2003).
20. Gácsi, M., Milósi, Á., Varga, O., Topál, J. & Csányi, V. Are readers of our face readers of our minds? Dogs (Canis familiar is) show
situation-dependent recognition of human’s attention. Anim. Cogn. 7, 144–153, https://doi.org/10.1007/s10071-003-0205-8 (2004).
21. Virányi, Z., Topál, J., Gácsi, M., Milósi, Á. & Csányi, V. Dogs respond appropriately to cues of humans’ attentional focus. Behav.
Process. 66, 161–172, https://doi.org/10.1016/j.beproc.2004.01.012 (2004).
22. S chwab, C. & Huber, L. Obey or not obey? Dogs (Canis familiar is) behave dierently in response to attentional states of their owners.
J. Comp. Psychol. 120, 169–175, https://doi.org/10.1037/0735-7036.120.3.169 (2006).
23. Nagasawa, M., Murai, ., Mogi, . & iusui, T. Dogs can discriminate human smiling faces from blan expressions. Anim. Cogn.
14, 525–533, https://doi.org/10.1007/s10071-011-0386-5 (2011).
24. Buttelmann, D. & Tomasello, M. Can domestic dogs (Canis familiaris) use referential emotional expressions to locate hidden food?
Anim. Cogn. 16, 137–145, https://doi.org/10.1007/s10071-012-0560-4 (2013).
25. Turcsán, B., Szántho, F., Milósi, Á. & ubinyi, E. Fetching what the owner prefers? Dogs recognize disgust and happiness in human
behaviour. Anim. Cogn. 18, 83–94, https://doi.org/10.1007/s10071-014-0779-3 (2015).
26. Udell, M. A., Dorey, N. . & Wynne, C. D. What did domestication do to dogs? A new account of dogs’ sensitivity to human actions.
Biol. Rev. Camb. Philos. Soc. 85, 327–345, https://doi.org/10.1111/j.1469-185X.2009.00104.x (2010).
27. Scheider, L., Grassmann, S., aminsi, J. & Tomasello, M. Domestic dogs use contextual information and tone of voice when
following a human pointing gesture. Plos One 6, e21676, https://doi.org/10.1371/journal.pone.0021676 (2011).
28. uffman, T. & Morris-Trainor, Z. Do dogs understand human emotional expression? J. Vet. Behav. 6, 97–98, https://doi.
org/10.1016/j.jveb (2011).
29. Fuuzawa, M., Mills, D. S. & Cooper, J. J. e eect of human command phonetic characteristics on auditory cognition in dogs
(Canis familiar is). J. Comp. Psychol. 119, 117–120, https://doi.org/10.1037/0735-7036.119.1.117 (2005).
30. Pongrácz, P., Milósi, Á. & Csányi, V. Owners’ beliefs on the ability of their pet dogs to understand human verbal communication:
A case of social understanding. Curr. Psychol. Cogn. 20, 87–107 (2001).
31. aminsi, J., Call, J. & Fischer, J. Word learning in a domestic dog: Evidence for ‘fast mapping’. Science 304, 1682–1683, https://doi.
org/10.1126/science.1097859 (2004).
32. Pilley, J. W. & eid, A. . Border collie comprehends object names as verbal referents. Behav. Process. 86, 184–195, https://doi.
org/10.1016/j.beproc.2010.11.007 (2011).
33. Williams, S. L., Brae, . E. & Savage-umbaugh, E. S. Comprehension sills of language-competent and nonlanguage-competent
apes. Lang. Commun. 17, 301–317 (1997).
34. Herman, L. M. eceptive competencies of language-trained animals. Adv. Stu dy Be hav. 17, 1–60 (1987).
35. Pepperberg, I. M. e Alex studies: Cognitive and communicative abilities of grey parrots. (Harvard University Press, 1999).
36. Young, C. A. Verbal commands as discriminative stimuli in domestic dogs (Canis familiaris). Appl. Anim. Behav. Sci. 32, 75–89,
https://doi.org/10.1016/S0168-1591(05)80165-0 (1991).
37. Ellis, S. L. H., ompson, H., Guijarro, C. & Zulch, H. E. e inuence of body region, handler familiarity and order of region
handled on the domestic cat’s response to being stroed. Appl. Anim. Behav. Sci. 173, 60–67, https://doi.org/10.1016/j.
applanim.2014.11.002 (2015).
38. amos, D. et al. Are cats (Felis catus) from multi-cat households more stressed? Evidence from assessment of fecal glucocorticoid
metabolite analysis. Physiol. Behav. 122, 72–75, https://doi.org/10.1016/j.physbeh.2013.08.028 (2013).
39. Bradshaw, J. & Cameron-Beaumont, C. e signalling repertoire of the domestic cat and its undomesticated relatives in e domestic
cat: e biology of its behaviour, 2nd edn. (eds Turner, D. C. & Bateson, P.) 67–93 (Cambridge University Press, 2000).
Content courtesy of Springer Nature, terms of use apply. Rights reserved
8
SCIENTIFIC REPORTS | (2019) 9:5394 | https://doi.org/10.1038/s41598-019-40616-4
www.nature.com/scientificreports
www.nature.com/scientificreports/
40. Olmstead, C. E. & Villablanca, J. . Development of behavioral audition in the itten. Physiol. Behav. 24, 705–712, https://doi.
org/10.1016/0031-9384(80)90401-1 (1980).
41. Matsumoto, . elation between the emotional stroop tas and the probe detection tas (In Japanese). Socio-Environ. Stud. 11,
203–216 (2006).
Acknowledgements
We wish thank the owners of the cats and Marsa Smith (cat café). We also thank Saho Takagi, Minori Arahori,
and Hitomi Chijiiwa for helping with data collection, Hiroki Koda for helping with auditory stimulus analysis. A.
Saito and T. Hasegawa were granted funding by Kakenhi (No. 25118003). A. Saito was supported with Incentive
Allowance for Dissemination of Individual Research Results by Sophia University.
Author Contributions
A.S., Y.I. and T.H. conceived and designed the experiments. A.S., K.S. and Y.I. performed the experiments and
analysed the behavioural data. K.S. conducted statistical analysis. A.S. and K.S. prepared the manuscript. K.S.
analysed auditory stimuli. A.S. and T.H. organized the research project. All the authors read and approved the
nal manuscript.
Additional Information
Supplementary information accompanies this paper at https://doi.org/10.1038/s41598-019-40616-4.
Competing Interests: e authors declare no competing interests.
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and
institutional aliations.
Open Access This article is licensed under a Creative Commons Attribution 4.0 International
License, which permits use, sharing, adaptation, distribution and reproduction in any medium or
format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Cre-
ative Commons license, and indicate if changes were made. e images or other third party material in this
article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the
material. If material is not included in the article’s Creative Commons license and your intended use is not per-
mitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the
copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
© e Author(s) 2019
Content courtesy of Springer Nature, terms of use apply. Rights reserved
1.
2.
3.
4.
5.
6.
Terms and Conditions
Springer Nature journal content, brought to you courtesy of Springer Nature Customer Service Center GmbH (“Springer Nature”).
Springer Nature supports a reasonable amount of sharing of research papers by authors, subscribers and authorised users (“Users”), for small-
scale personal, non-commercial use provided that all copyright, trade and service marks and other proprietary notices are maintained. By
accessing, sharing, receiving or otherwise using the Springer Nature journal content you agree to these terms of use (“Terms”). For these
purposes, Springer Nature considers academic use (by researchers and students) to be non-commercial.
These Terms are supplementary and will apply in addition to any applicable website terms and conditions, a relevant site licence or a personal
subscription. These Terms will prevail over any conflict or ambiguity with regards to the relevant terms, a site licence or a personal subscription
(to the extent of the conflict or ambiguity only). For Creative Commons-licensed articles, the terms of the Creative Commons license used will
apply.
We collect and use personal data to provide access to the Springer Nature journal content. We may also use these personal data internally within
ResearchGate and Springer Nature and as agreed share it, in an anonymised way, for purposes of tracking, analysis and reporting. We will not
otherwise disclose your personal data outside the ResearchGate or the Springer Nature group of companies unless we have your permission as
detailed in the Privacy Policy.
While Users may use the Springer Nature journal content for small scale, personal non-commercial use, it is important to note that Users may
not:
use such content for the purpose of providing other users with access on a regular or large scale basis or as a means to circumvent access
control;
use such content where to do so would be considered a criminal or statutory offence in any jurisdiction, or gives rise to civil liability, or is
otherwise unlawful;
falsely or misleadingly imply or suggest endorsement, approval , sponsorship, or association unless explicitly agreed to by Springer Nature in
writing;
use bots or other automated methods to access the content or redirect messages
override any security feature or exclusionary protocol; or
share the content in order to create substitute for Springer Nature products or services or a systematic database of Springer Nature journal
content.
In line with the restriction against commercial use, Springer Nature does not permit the creation of a product or service that creates revenue,
royalties, rent or income from our content or its inclusion as part of a paid for service or for other commercial gain. Springer Nature journal
content cannot be used for inter-library loans and librarians may not upload Springer Nature journal content on a large scale into their, or any
other, institutional repository.
These terms of use are reviewed regularly and may be amended at any time. Springer Nature is not obligated to publish any information or
content on this website and may remove it or features or functionality at our sole discretion, at any time with or without notice. Springer Nature
may revoke this licence to you at any time and remove access to any copies of the Springer Nature journal content which have been saved.
To the fullest extent permitted by law, Springer Nature makes no warranties, representations or guarantees to Users, either express or implied
with respect to the Springer nature journal content and all parties disclaim and waive any implied warranties or warranties imposed by law,
including merchantability or fitness for any particular purpose.
Please note that these rights do not automatically extend to content, data or other material published by Springer Nature that may be licensed
from third parties.
If you would like to use or distribute our Springer Nature journal content to a wider audience or on a regular basis or in any other manner not
expressly permitted by these Terms, please contact Springer Nature at
onlineservice@springernature.com
... www.nature.com/scientificreports/ Cats have been shown to distinguish their own from another familiar cat's name in a habituation-dishabituation procedure 25 , and they also distinguished those names from general nouns. Interestingly, cats living in multi-cat households habituated less to their companion cats' names than to other nouns. ...
... Saito et al. showed that café cats did not distinguish their own name from the name of cohabiting cats whereas household cats did so, in a www.nature.com/scientificreports/ habituation-dishabituation procedure 25 . We extend this finding by showing that café cats also do not appear to learn the association between another cat's name and its face. ...
... In Exp.1, we found a difference between household cats and café cats. Previous studies have reported several behavioral differences between these two groups 24,25,36 . In Saito et al. house cats but not café cats were shown to recognize their own name; café cats did not discriminate their own name from names of other cats living in the same environment. ...
Article
Full-text available
Humans communicate with each other through language, which enables us talk about things beyond time and space. Do non-human animals learn to associate human speech with specific objects in everyday life? We examined whether cats matched familiar cats’ names and faces (Exp.1) and human family members’ names and faces (Exp.2). Cats were presented with a photo of the familiar cat’s face on a laptop monitor after hearing the same cat’s name or another cat’s name called by the subject cat’s owner (Exp.1) or an experimenter (Exp.2). Half of the trials were in a congruent condition where the name and face matched, and half were in an incongruent (mismatch) condition. Results of Exp.1 showed that household cats paid attention to the monitor for longer in the incongruent condition, suggesting an expectancy violation effect; however, café cats did not. In Exp.2, cats living in larger human families were found to look at the monitor for increasingly longer durations in the incongruent condition. Furthermore, this tendency was stronger among cats that had lived with their human family for a longer time, although we could not rule out an effect of age. This study provides evidence that cats link a companion's name and corresponding face without explicit training.
... Although the latter were not animal behavior experts, previous studies have indicated that familiarity with animal subjects is not critical for rating many of behaviors. Tami and Gallagher demonstrated that different types of observers including dog-owners, veterinarians, dog trainers and non-owners classified dogs' behaviors (e.g., as friendly or aggressive) correctly [40], regardless of degree of familiarity with dogs (see also [23,41]). Furthermore, agreements between raters in our three experiments, as indicated by Cronbach's coefficient alphas, were high (Exp.1: ...
Article
Full-text available
Many animals probably hold mental representations about the whereabouts of others; this is a form of socio-spatial cognition. We tested whether cats mentally map the spatial position of their owner or a familiar cat to the source of the owner’s or familiar cat’s vocalization. In Experiment 1, we placed one speaker outside a familiar room (speaker 1) and another (speaker 2) inside the room, as far as possible from speaker 1, then we left the subject alone in the room. In the habituation phase, the cat heard its owner’s voice calling its name five times from speaker 1. In the test phase, shortly after the 5 th habituation phase vocalization, one of the two speakers played either the owner’s voice or a stranger’s voice calling the cat’s name once. There were four test combinations of speaker location and sound: Same sound Same location , Same sound Diff location , Diff sound Same location , Diff sound Diff location . In line with our prediction, cats showed most surprise in the Same sound Diff location condition, where the owner suddenly seemed to be in a new place. This reaction disappeared when we used cat vocalizations (Experiment 2) or non-vocal sounds (Experiment 3) as the auditory stimuli. Our results suggest that cats have mental representations about their out-of-sight owner linked to hearing the owner’s voice, indicating a previously unidentified socio-spatial cognitive ability.
... Furthermore, new tests of perception abilities in cats should also include olfaction, not just vision, since olfaction plays an important role in the social lives of cats but probably also individual recognition of humans. Studies have found evidence that cats can distinguish between individual humans, and Saito et al. [37] demonstrated that they can distinguish between the voices of their owners and strangers. Although we now have good descriptions of cat vocalizations, we need more work on what they mean when they employ them in interactions with humans; here, the phonetic methods first used by Schötz et al. [38] might be helpful. ...
Article
Full-text available
After recent publication of several reviews covering research results from the last 35 years of domestic cat studies, a number of important unanswered questions and hypotheses have arisen that could interest active researchers, especially those beginning their academic careers. Some sections of this paper concern methodologies that have yielded new insights and could provide more in the future; other sections concern findings and interpretations of those that need further testing. First, hypotheses arise from combining subjective (or psychological) assessments of cat and human personality traits and observational (ethological) studies of cat–human interactions: e.g., do owners with high attachment to their cats interact differently with them than owners with low attachment levels? New analytical methods of dyadic interaction observations open the door for testing further hypotheses. In particular, the Theme® (Noldus bv, NL) program could be used to determine if there are differences between cat breeds in interaction patterns with people, which is not only of interest to owners but also therapists employing cats in their practices. Cat breed differences have been found using subjective ratings, but these need to be corroborated by direct observational data from the home setting and/or non-invasive colony observations, since ratings based on anthropomorphic projections might not be reliable. This should be done before searching for the genetic basis of such differences. Reliable information on breed differences is also needed before prescribing certain breeds for animal-assisted interventions. A model has predicted that the degree of socialization as a kitten affects cats’ responses to positive and negative experiences with unfamiliar humans and their formation of feline–human relationships later on. This needs to be tested in an ethically approved manner on cats of known socialization status and has enormous consequences for cat adoptions from animal shelters. Observations of human–cat interactions have yielded many correlations, which can be tested by non-invasive manipulations of human behavior in the home setting. Examples of these will be given and are of general interest to the cat-owning public. A review of first findings on social cognition in cats has resulted in further unanswered questions and hypotheses. Finally, two aspects of domestic cat ecology will be considered (effects on wildlife and space utilization), which are of great interest to the public and conservationists alike.
... We also observed an interaction between the test type and the attentional state of the caregiver: when the caregiver was inattentive, cats showed less sequential behaviors, but only during the unsolvable condition. Our results challenge the popular notion that cats are independent and not people-oriented, and add to the emerging scientific literature that provides evidence that cats can form attachment bond with humans , have successful vocal communication with humans (McComb et al. 2009;Nicastro 2004;Saito and Shinozuka 2013;Saito et al. 2019;Takagi et al. 2019), can recognize attentional states in humans ( (Mertens and Turner, 1988;Ito et al. 2016;, and use human-directed cues (Miklósi et al. 2005;Kraus et al. 2014;Pongrácz et al. 2019). Our results suggest that cats are attuned to their socio-cognitive environment, address intentional behavior at humans to access resources out of their reach, and take into account the attentional availability of humans. ...
Article
Full-text available
Research on social cognitive ability in domestic cats is limited. The current study investigated social referencing in cats when exposed to first, a solvable, and then, an unsolvable scenario (i.e., reachable and unreachable treats) in the presence of either an attentive or an inattentive caregiver. Cats expressed more gaze alternation ( P = 0.013), but less interaction with the caregiver ( P = 0.048) and approached the treat container less frequently ( P = 0.017) during the unsolvable test, compared to the solvable test. When in the presence of an attentive caregiver, cats initiated first gaze at the caregiver faster ( P = 0.001); gazed at the caregiver for longer ( P = 0.034); and approached the treat more frequently ( P = 0.040), compared to when the caregiver was inattentive. Significant interaction was observed between test and caregiver’s attentional state on the expression of sequential behavior, a type of showing behavior. Cats exhibited this behavior marginally more with attentive caregivers, compared to inattentive caregivers, but only during the unsolvable test. There was a decrease in sequential behavior during the unsolvable test, compared to solvable test, but this was only seen with inattentive caregivers ( P = 0.018). Our results suggest that gaze alternation is a behavior reliably indicating social referencing in cats and that cats’ social communication with humans is affected by the person’s availability for visual interaction.
... Ellis et al. (27) reported that 40% of their human participants identified the correct contexts of cat vocalizations more often than by chance when the vocalizations belonged to their own cat, but did not perform above chance when the calls belonged to an unfamiliar cat. Interestingly, Saito et al. (28) demonstrated with the habituation-dishabituation method that privately owned cats can discriminate their own names from other words, which leads now to other studies in the area of social cognition in cats. ...
Article
Full-text available
This is a mini review that summarizes what is known from quantitative observational studies of social interactions between domestic cats and humans in both laboratory colonies and the home setting. Only results from data that have been statistically analyzed are included; hypotheses still to be tested will be declared as such. In some cases, the observational data have been combined with independently collected subjective assessments by the owners of the animals' character and owner personality traits to help interpret the data. Further some relevant experimental studies are also included. All social interactions between cats and humans that are discussed below assume that the animals were socialized to people as kittens, the first topic of this review. Such socialized cats show what might be called “friendliness to humans,” which in turn affects human attachment to the cat. The visual and acoustic behavioral elements used to communicate and interact with other cats can be perceived by people and are also employed by the cats when interacting with them. The initiation, and the initiator of social interactions between cats and humans have been shown to influence both the duration of the interaction bout and total interaction time in the relationship. Compliance with the interactional “wishes” of the partner is positively correlated between the cats and the humans over all human-cat dyads examined. Cats do not spontaneously prefer one gender or age cohort of people, but the humans in those cohorts behave differently to the cats causing the latter to react differentially. The dyadic interaction structure has also been shown to differ between women and men and between older and younger adults. Nevertheless, cats—merely their presence but of course their behavior—can affect human moods and human mood differences have been shown to affect the behavior of the cats. Finally, differences have been found between interactions with purebred and non-purebred cats and between younger and older cats.
... Importantly, about two thirds of our subjects were from cat cafés, which makes us cautious about generalizing the results of this study to all domestic cats. Recent studies have focused on possible differences in the nature of the bonds with owners in house and café cat populations (Bucher et al., 2020;Saito et al., 2019;Takagi et al., 2019). Although we found no differences between house and café cats, their owner-attachment and socialization histories seem likely to differ. ...
Article
Humans evaluate others based on interactions between third parties, even when those interactions are of no direct relevance to the observer. Such social evaluation is not limited to humans. We previously showed that dogs avoided a person who behaved negatively to their owner (Chijiiwa et al., 2015). Here, we explored whether domestic cats, another common companion animal, similarly evaluate humans based on third-party interactions. We used the same procedure that we used with dogs: cats watched as their owner first tried unsuccessfully to open a transparent container to take out an object, and then requested help from a person sitting nearby. In the Helper condition, this second person (helper) helped the owner to open the container, whereas in the Non-Helper condition the actor refused to help, turning away instead. A third, passive (neutral) person sat on the other side of the owner in both conditions. After the interaction, the actor and the neutral person each offered a piece of food to the cat, and we recorded which person the cat took food from. Cats completed four trials and showed neither a preference for the helper nor avoidance of the non-helper. We consider that cats might not possess the same social evaluation abilities as dogs, at least in this situation, because unlike the latter, they have not been selected to cooperate with humans. However, further work on cats’ social evaluation capacities needs to consider ecological validity, notably with regard to the species’ sociality.
... Although research on domestic cat behavior and cognition is growing [37], cat cognitive and communicative skills have been far less investigated than those of dogs, and the literature on the cat-human relationship and communication is more sparse and limited [10,38]. Only a handful of studies have investigated cat vocalizations and the characteristics of cat-human communication [39][40][41][42][43] and little is known about the human ability to recognize and classify the context and the possible emotional content of cat-to-human vocalizations [44][45][46]. ...
Article
Full-text available
Simple Summary: Cat-human communication is a core aspect of cat-human relationships and has an impact on domestic cats' welfare. Meows are the most common human-directed vocalizations and are used in different everyday contexts to convey emotional states. This work investigates adult humans' capacity to recognize meows emitted by cats during waiting for food, isolation, and brushing. We also assessed whether participants' gender and level of empathy toward animals in general, and toward cats in particular, positively affect the recognition of cat meows. Participants were asked to complete an online questionnaire designed to assess their knowledge of cats and to evaluate their empathy toward animals. In addition, they listened to cat meows recorded in different situations and tried to identify the context in which they were emitted and their emotional valence. Overall, we found that, although meowing is mainly a human-directed vocalization and should represent a useful tool for cats to communicate emotional states to their owners, humans are not good at extracting precise information from cats' vocalizations and show a limited capacity of discrimination based mainly on their experience with cats and influenced by gender and empathy toward them. Abstract: Although the domestic cat (Felis catus) is probably the most widespread companion animal in the world and interacts in a complex and multifaceted way with humans, the human-cat relationship and reciprocal communication have received far less attention compared, for example, to the human-dog relationship. Only a limited number of studies have considered what people understand of cats' human-directed vocal signals during daily cat-owner interactions. The aim of the current study was to investigate to what extent adult humans recognize cat vocalizations, namely meows, emitted in three different contexts: waiting for food, isolation, and brushing. A second aim was to evaluate whether the level of human empathy toward animals and cats and the participant's gender would positively influence the recognition of cat vocalizations. Finally, some insights on which acoustic features are relevant for the main investigation are provided as a serendipitous result. Two hundred twenty-five adult participants were asked to complete an online questionnaire designed to assess their knowledge of cats and to evaluate their empathy toward animals (Animal Empathy Scale). In addition, participants had to listen to six cat meows recorded in three different contexts and specify the context in which they were emitted and their emotional valence. Less than half of the participants were able to associate cats' vocalizations with the correct context in which they were emitted; the best recognized meow was that emitted while waiting for food. Female participants and cat owners showed a higher ability to correctly classify the vocalizations emitted by cats during brushing and isolation. A high level of empathy toward cats was significantly associated with a better recognition of meows emitted during isolation. Regarding the emotional valence of meows, it emerged that cat vocalizations emitted during isolation are perceived by people as the most negative, whereas those emitted during brushing are perceived as most positive. Overall, it emerged that, although meowing is mainly a human-directed vocalization and in principle represents a useful tool for cats to communicate emotional states to their owners, humans are not particularly able to extract precise information from cats' vocalizations and show a limited capacity of discrimination based mainly on their experience with cats and influenced by empathy toward them.
Article
Research into cat behavior has gained more attention in recent years. As one of the world’s most popular companion animals, work in this field has potential to have wide-reaching benefits. Cats living in shelters are posed with distinct welfare concerns. Shelter cat welfare can be increased through use of environmental enrichment to promote natural behaviors. This review focuses on relevant literature published to date on shelter cat enrichment. Several key areas of research were identified. These included sensory enrichment, feeding enrichment, physical enrichment, social enrichment, and assessments to determine cat preference for enrichment stimuli. Existing studies have examined the efficacy of enrichment to promote species-specific behaviors and to reduce stress in shelter cats. Studies have also explored housing conditions for shelter cats such as cage size, communal housing, or the general quality of the environment. Applications of this information are discussed in order to promote natural cat behavior and find ways to increase the welfare of shelter cats. A review of the literature highlights the importance of supplying novel items in shelter environments, providing a rotation of individually preferred items, the use of human social interaction as a way to increase interactive behaviors in shelter cats, and the importance of considering potentially aversive impacts of enrichment under certain situations.
Chapter
Cats, along with dogs, are one of the most popular companion animals for humans. Across the world, increasing numbers of cats are being kept as pets. Despite their familiarity, cats’ cognition has long been shrouded in mystery, mainly because cats were considered largely unsuitable for psychological studies in laboratory settings. The “Cats Team” in Kazuo Fujita’s lab has developed several innovative and useful methods for studying cat cognition. In this chapter, I review findings from some of the team’s studies of cat cognition, including physical inference, use human social cues, incidental memory, cross-modal integration, jealousy, and third-party social evaluation. I also briefly describe some ongoing work on the relation between genes and personality, and suggest directions in which behavioral and cognitive studies of cats might go.
Article
Full-text available
The ability of domestic dogs (C. lupus famaliaris) to follow and attend to human emotion expressions is well documented. It is unknown whether domestic cats (F. silvestris catus) possess similar abilities. Because cats belong to the same order (Carnivora), but did not evolve to live in complex social groups, research with them enables us to tease apart the influence of social structure versus domestication processes on the capacity to recognize human communicative cues, such as emotions. Two experiments were conducted to determine the extent to which domestic cats discriminate between human emotion cues. The first experiment presented cats with facial and postural cues of happiness and anger from both an unfamiliar experimenter and their familiar owner in the absence of vocal cues. The second experiment presented cats with vocal cues of human emotion through a positively or negatively charged conversation between an experimenter and owner. Domestic cats were only modestly sensitive to emotion, particularly when displayed by their owner, suggesting that a history of human interaction alone may not be sufficient to shape such abilities in domestic cats.
Article
Full-text available
Cats’ (Felis catus) communicative behaviour towards humans was explored using a social referencing paradigm in the presence of a potentially frightening object. One group of cats observed their owner delivering a positive emotional message, whereas another group received a negative emotional message. The aim was to evaluate whether cats use the emotional information provided by their owners about a novel/unfamiliar object to guide their own behaviour towards it. We assessed the presence of social referencing, in terms of referential looking towards the owner (defined as looking to the owner immediately before or after looking at the object), the behavioural regulation based on the owner’s emotional (positive vs negative) message (vocal and facial), and the observational conditioning following the owner’s actions towards the object. Most cats (79 %) exhibited referential looking between the owner and the object, and also to some extent changed their behaviour in line with the emotional message given by the owner. Results are discussed in relation to social referencing in other species (dogs in particular) and cats’ social organization and domestication history.
Article
Full-text available
Research using the two-object choice paradigm showed that dogs prefer the object associated with the happy human emotion. However, they provided rather ambiguous results regarding the negative emotions. We assumed that differences between the dogs' and owners' interest towards the 'negative' object might be responsible for this. In our experiment, dogs observed their owner expressing different emotions towards two uniform plastic bottles. Five dog groups were tested based on the condition they received: (1) happy versus neutral, (2) happy versus disgust, (3) neutral versus disgust and (4-5) neutral vs neutral, as control groups. Contrary to previous studies using free choice paradigm, we used a task-driven approach. After the demonstration, the dogs had to retrieve one object to the owner. The dogs' performance in the two neutral-neutral groups did not differ from the chance level. In contrast, subjects were able to distinguish between the happy and neutral expression of the owner: they both approached and fetched the 'happy' object. In the happy-disgusted and neutral-disgusted groups, the dogs approached the bottles randomly, suggesting that they found the 'disgusting' and 'neutral' objects equally attractive. Nevertheless, the dogs preferentially retrieved the object marked with the relatively more positive emotion (happy or neutral) to the owner in both conditions. Our results demonstrate that dogs are able to recognize which is the more positive among two emotions, and in a fetching task situation, they override their own interest in the 'disgusting' object and retrieve what the owner prefers.
Article
Full-text available
this paper should be addressed to S. L. Williams, Language Research Center, 3401 Panthersville Road, GA 30034, U.S.A. 301 S. WILLIAMS et al. on the object and with the object as though the object was an animate being. The ape is also expected to know that it must imitate the actions of the caretaker actions that during the demonstration are directed toward the caretaker herself. The ape needs both to imitate what it sees and also to understand the intent of the speaker. A dog cannot achieve such an understanding, but apes often can (Hayes, as can young children (Bates et al., making it difficult to determine whether correct responses with such contexts are based upon language comprehension per se or upon extralinguistic cues. Of course, it is often impractical, with apes and children alike, to demand that language comprehension be context-free before one recognizes that it is occurring. To ensure the very process of language acquisition, the parent or caregiver must have some understanding of a young child's or ape's level of comprehension even as they start to comprehend. The beginning of language comprehension in children can be observed between months of age (Bates, 1993). Throughout this time, an adult may not always be aware of the degree to which he or she is monitoring a child's development of comprehension, but nonetheless the caregiver has a relatively good understanding of what the child can comprehend; and she or he will direct communications to the child accordingly (e.g. Bates, 1993). Given that context does influence this process, we looked at the comprehension of spoken English sentences in a pair of bonobos (Pan paniscus). To date, three bonobos and one common chimpanzee (Pan troglodytes) have demonstrated a capacity to understand speech and graphic sy...
Article
We tested whether cats (Felis catus) could recognize human attentional states when begging for food from one of two unfamiliar actors. Cats were tested under three conditions that differed in the actors’ actions: Visual only condition—the actor looking at the cat silently versus facing sideways silently; Visual and Auditory condition—the actor looking at and calling to the cat versus looking at the cat silently; and Auditory only condition—the actor facing down and calling to the cat versus facing down silently. In the Visual and Auditory condition, cats preferred the actor who was calling to them. In the Visual only and the Auditory only conditions, the cats showed no preference for the actors’ attentional states. There was a modest difference in the preference between the Visual and Auditory condition and the Auditory only condition. These results suggest that cats can use vocal cues of attention toward them only in situations in which humans are looking at them.
Article
This paper presents results of almost 30 years of study of the cognitive and communicative activities of Grey parrots (Psittacus erithacus), conventionally regarded as mindless mimics. These studies have demonstrated that Grey parrots can solve various cognitive tasks and acquire and use English speech in ways that often resemble those of very young children. Examples include the concepts of same/different, colour, size and shape. The parrot Alex can also recognize and distinguish numbers up to six, and spontaneously demonstrated his ability to grasp the concept of "none". Given the evolutionary distance between birds and mammals, these results have intriguing implications for the evolution of intelligence, the study of comparative intelligence, and the care and maintenance of birds held in captivity in zoos and as companion animals. (c) 2006 Elsevier B.V. All rights reserved.
Chapter
The chapter discusses on what is known of the receptive competencies of animals in language like tasks. The emphasis is on the extensive work with apes, as well as the recent work with marine mammals, bottle-nosed dolphins. Sign language projects have given little attention to receptive competencies. Generally, data from these studies are insufficient for judging the degree to which apes understand the signs of their trainers. The most extensive attempt to quantify sentence comprehension in apes was that by Premack. The chimps Sarah, Peony, and Elizabeth were tutored in a system in which plastic symbols of arbitrary shape and color were used to represent objects, properties, and actions within an artificial language. Sentences could be constructed, by the experimenter or by the chimp, by arranging the symbols in a linear array on a board. There is evidence for an asymmetry of comprehension and production in the development and maintenance of language in humans. During early childhood, comprehension generally precedes and exceeds production. The ability of dolphins to understand imperative and interrogative sentences expressed within artificial acoustic or gestural languages is examined. Two young female bottle-nosed dolphins (Tursiops truncatus), housed together in a large seawater tank, were tutored in the artificial languages.
Article
The domestic cat is now one of the most common pet species in the Western world. As part of its role as a pet, cats are expected to not only tolerate but enjoy being touched. This study consisted of two experiments, with the first investigating the influence of body region touched and handler familiarity on the domestic cat's behavioural response to being stroked. The second experiment extended this work by investigating the influence of order of body region touched on behavioural responses. Both handler familiarity and body region stroked significantly influenced negative behavioural responses. Familiar handling, in comparison to unfamiliar handling, led to significantly higher negative behavioural scores displayed by the cats (Z = −3.235, N = 34, p = 0.001). When considering the different body regions investigated, the caudal region produced the highest negative scores both when handled by the unfamiliar person (Experiment 1: χ2 = 14.330, N = 34, p = 0.046) and by the familiar person (Experiment 2: χ2 = 18.387, N = 20, p = 0.002). Order of body region touched had no significant bearing on behavioural responses exhibited. Results suggest that handling of cats should avoid the caudal region and highlight the need for further investigation into the owner–cat relationship.
Article
The domestic cat is the only member of the Felidae to form social relationships with humans, and also, the only small felid to form intraspecific social groups when free ranging. The latter are matriarchies, and bear only a superficial similarity to those of the lion and cheetah, which evolved separately and in response to very different selection pressures. There is no evidence for intraspecific social behavior in the ancestral species Felis silvestris, and hence, the capacity for group formation almost certainly evolved concurrently with the self-domestication of the cat during the period 10,000 to 5,000 years before present. Social groups of F. catus are characterized by cooperation among related adult females in the raising of kittens from parturition onward and competition between adult males. Unlike more social Carnivora, cats lack ritualized submissive signals, and although "peck-order" hierarchies can be constructed from exchanges of aggressive and defensive behavior, these do not predict reproductive success in females, or priority of access to key resources, and thus do not illuminate the basis of normal cat society. Cohesion in colonies of cats is expressed as, and probably maintained by, allorubbing and allogrooming; transmission of scent signals may also play a largely uninvestigated role. The advantages of group living over the ancestral solitary territorial state have not been quantified adequately but are likely to include defense of permanent food sources and denning sites and protection against predators and possibly infanticide by invading males. These presumably outweigh the disadvantages of communal denning, enhanced transmission of parasites, and diseases. Given the lack of archaeological evidence for cats kept as pets until some 4,000 years before present, intraspecific social behavior was most likely fully evolved before interspecific sociality emerged. Signals directed by cats toward their owners fall into 3 categories: those derived from species-typical actions, such as jumping up, that become signals by association; signals derived from kitten-to-mother communication (kneading, meow); and those derived from intraspecific cohesive signals. Social stress appears widespread among pet cats, stemming from both agonistic relationships within households and territorial disputes with neighborhood cats, but simple solutions seem elusive, most likely because individual cats vary greatly in their reaction to encounters with other cats.