出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

vol.61, no.1, pp.1-5, 2011

著者

森戸 義一

出版者

The Japanese Society for Animal Psychology

雑誌

動物心理 (ISSN:18836275)

巻号頁・発行日

vol.4, no.1, pp.8-36, 1938-07-15 (Released:2009-10-13)

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In the study hitherto made of cocks' crowing, it was understood that results obtained from various experiments can be explained to dep nd upon function of a hormone and especially it came to be known that its mechanism c nsists in the fact that certain periodical stimulus is given to internal organs by a testicle-hormone. So I made some experiments on same cocks, in wich the hormone activity was artificially weakened or to which a hormone drug was injected Now I will report here the results of these experiments.1. Even though one of a cock's testicles is removed in the chicken stage, its crowing behaviour presents itself as it grows up. But it takes a great many days for the crowing-on an average 87 days more than in normal cocks to give the first utterance and 3 days more for the normal utterance.2. Though is imperfect, it gradually becomes regulated. But the time-duration of crowing is generally short in any case.3.The frequen y is generally small and it is reduced to less t an half of that in normal cocks.4. The number of days required for their utterance is very large, while that for the normal utterance is comparatively small. The former results from the development of their bodily and vocal organs, and the latter from their learning to crow.5. The above-mentioned changes take place on account of their onesided testicle and the fact that their inner function was reduced to less than half of that in normal cocks.6. Every crowing at the early dawn uttered by animals with a single testicle is not constant or in some cases it is not uttered at all.7. The frequency of their crowing decreases extremely, and it cannot be observed that it comes to increase as the crowing is repeated in regular order., as is se n in normal cocks.8. When the cocks which do not crow at the early dawn or constantly are treated with the hormone, they all come to be able to utter a crowing.9. Though in this case the number of times of the crowing shows no increase, yet it is far larger than before.10. In the course of development which takes place in those injected with a hormone of the opposite sex we can see that it takes a great many days for the first utterance, but it is given earlier than that in those whose single testicle is removed in the stage of chickens. So it is certain that the grade of inhibition done to the crowing by an application of a hormone of the opposite sex ranks between that in the case of normal cocks and that in the case of those wi h a single tisticle.11. The crowing of the cocks treated with a hormone of the opposite sex is imperfect in the vocal note, short in time duration, and generally seems to be week in power.12. In those supplied with a hormone of the opposite sex, the crowing at the early dawn is irregular among the individuals.13. The above changes are due to the impediment given to the functions or periodical vocal utterance in the male sex.14. The pr sence of testicle is an indispensable condition for the cock's crowing without which it can never be realized.15. When a hormone of the same sex is supplied to the cocks whose natural crowing behaviour has been changed through an inhibitory effect given by a hormone of the opposite sex. They came to regain the function assigned to the male sex.16. In this case the more powerful a hormone of the same sex is, the greater becomes its effect.17. When one of the testicles of a grown-up cock is removed. it stops crowing for a few days but later it comes to crow again. In the latter case the frequency is reduced to less than half of that in normal individuals.18. It is quite impossible for grown-up cocks with a single testicle to utter a crowing at the early dawn. Even if they crow now and then, it is very difaicult for them to tell the exact time.

著者

森戸 義一

出版者

The Japanese Society for Animal Psychology

雑誌

動物心理 (ISSN:18836275)

巻号頁・発行日

vol.3, no.1-2, pp.1-41, 1936-10-20 (Released:2010-01-28)

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It is the principal aim of my experience to examine what mechanism the cocks' crowing at the early dawn is based on.For this purpose a couple of genuine white leghorns was chosen, from whom were gained more than 20 eggs, and they were hatched.Among them only the cocks numbering 12 were bred and used for the experimental material. These 12 cocks were slowly separated from one another until each one of them was bred by itself. Putting these individuals under the entirely same condition from the time of chickens, I examined the results of the following three experiments.1) Changes of vocal sound as each individual becomes older.2) Comparison in normal crowing between separation and cohabitation.3) Comparison in normal crowing at the early dawn between the normal cocks and the deaf cocks.Now, this article is the conclusion which I have arrived at in the experiments.By the way the deaf cocks are those which when 200 days passed after their hatch were bored a hole in the tympanum of their ears after complete sterilization and the holes were filled with guttapercha used in dental surgery and then their burr edges were closed with three stiches.1. Under the same experimental condition, the age when the cocks utter for the first time is 142 days on the average.2. Each of the cocks does not give its first utterance except in the morning. The first utterance can never be heard in the afternoon, still less in the evening.3. The sound of voice in the first utterance is divided into a voiceless and a voiced sound. Then a change takes place when they begin to crow in normal note.4. The note of first utterance is generally “kc : ”, while some of the cocks rarely utter in the note of “kc : c” and others in “kcc : c”.5. The note in normal crowing is “kcke kc kcu.” The sooner the cocks can utter these two underlined assimilated sounds, the smaller is the number of times of their change of note from the first utterance to normal crowing. The smaller is the number of times of vocal change, the more rapid is its process.6. The days tend to become more and more from the first utterance to normal crowing, the more are the days to be spent between the hatching and the first utterance.7. The more are the days from the first utterance to the normal crowing, the smaller is the number of times of vocal change.8. The days to be spent from the hatching to the first utterance, and the days from the first utterance to normal crowing ; the gaining in weight and the lengthening of the cockscomb-between these things there can be seen no remarkable relation. Neither the cocks' growth by the day nor the gaining in their weight has anything to do with the number of times of normal crowing. The hours of normal crowing, however, have a close connetion to the growth by the day.9. As for the number of times of normal crowing in a day, there are some individual differences among the cocks coming out of the same parents, but the number of times that each one of them crows for itself is almost constant. The length of daytime, however, has a great influence upon the number of times of normal crowing. For this reason the number in June whose days are long, is larger than that of November. But the number of times at the early dawn is not related to any season. Another thing is that on the whole the number of times is distinctly smaller in cohabitation than in separation.10. The number of times of normal crowing is small for a certain while before and after noon, and the number becomes smaller and smaller towards evening. In the evening the cocks utter frequent crows periodically at a single time, and the stop crowing at sunset. These frequent crows are uttered at the same hours in case of “brother-cocks”.

著者

永山 博通 小出 剛

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

vol.69, no.2, pp.127-135, 2019 (Released:2019-12-18)

参考文献数

37

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Social behavior is a conspecific interaction and plays an important role in the survival of animals. In contrast, while heterospecific interaction largely refers to predator ― prey interaction, occasional instances of cooperative behavior can be found, for example, the interaction between domesticated animals and humans. Domestication involves breeding animals for generations to familiarize them with humans without fear. A major behavioral characteristic of domesticated animals is tameness which is divided into two categories. One is reluctant to avoid humans (passive tameness) and the other actively approaches humans (active tameness). Until now, however, little is known about the genetic, behavioral and neurological basis of these two categories of tameness. Here, we briefly review genetic and neurological research on tameness. Next, we explore the relationship between tameness and social cognitive skills of domesticated animals, such as dogs. Finally, we discuss the possibility of the same brain regions being used in both conspecific and heterospecific interactions.

著者

子安 ひかり 永澤 美保

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

pp.69.2.3, (Released:2019-07-18)

参考文献数

23

被引用文献数

4 5

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For animals living in groups such as some primates including humans and wolves, it is important to recognize the gaze of others and change their behavior accordingly. Dogs, which have a common ancestor with wolves, gained the ability to read human's gaze even though they are different species in the process of domestication. Although cats are originally solitary animals, cats sharing their living space with humans are frequently observed in modern days. Recent study showed that cats are likely to be able to detect the human gaze directed to themselves. In this study, we examined whether cats are able to recognize the human gaze and whether to change their behavior according to it. We investigated whether cats show different behaviors depending on the direction of the human gaze. As a result, when humans looked at the cats, the time which the cats looked back at the humans was shorter, regardless of familiarity and distance with the humans and the social situation. Also, when humans look at cats when the distance between individuals is short, the eyeblink frequency of cats increases. From these facts, it was shown that cats could recognize directedgaze from humans and change their behavior accordingly.

著者

永山 博通 小出 剛

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

pp.69.1.13, (Released:2019-11-29)

参考文献数

37

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Social behavior is a conspecific interaction and plays an important role in the survival of animals. In contrast, while heterospecific interaction largely refers to predator ― prey interaction, occasional instances of cooperative behavior can be found, for example, the interaction between domesticated animals and humans. Domestication involves breeding animals for generations to familiarize them with humans without fear. A major behavioral characteristic of domesticated animals is tameness which is divided into two categories. One is reluctant to avoid humans (passive tameness) and the other actively approaches humans (active tameness). Until now, however, little is known about the genetic, behavioral and neurological basis of these two categories of tameness. Here, we briefly review genetic and neurological research on tameness. Next, we explore the relationship between tameness and social cognitive skills of domesticated animals, such as dogs. Finally, we discuss the possibility of the same brain regions being used in both conspecific and heterospecific interactions.

著者

宮崎 雅雄 上野山 怜子

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

vol.72, no.2, pp.39-44, 2022 (Released:2022-12-16)

参考文献数

26

被引用文献数

1

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The domestic cat is a very popular companion animal. However, there is very little work focusing on cat-specific physiology and behavior. In this review, we introduce our studies uncovering scent signals for species- and sex-recognition and the behavioral significance of the silver vine response in cats. Cat urine emits a specific catty smell. Our chemical analysis identified a sulfur-containing volatile organic compound, 3-mercapto-3-methyl-1-butanol, that is detectable in the urine of cats but not of dogs and humans. In addition, its level varies between sexes; its level is markedly higher in intact males than in castrated males or females. These indicate that the sulfur-containing compound is a urinary scent signal involved in species- and sex-recognition in cats. The other characteristic in cats is the behavioral response to silver vine, which comprises licking and chewing the plants, rubbing against the plants, and rolling over on the plants. Previous studies identified some bioactive compounds designated as matatabilactones from the plants, but little is known about why cats do the response to the plants. Our analyses found that nepetalactol which was missed in the plants is a potent bioactive compound for the response and stimulates the μ-opioid system which is responsible for the euphoria in humans. Nepetalactol has the repellent activity of pest insects such as mosquitoes. The rubbing and rolling responses to the plants transfer nepetalactol onto the feline fur that repels mosquitoes. The licking and chewing of the plants changes not only emission levels of nepetalactol and matatabilactones but also their contents which increase bioactivities toward cats and mosquitoes. These findings improve our understanding of the species-specific physiology and behavior in cats.

著者

谷内 通 増山 崇

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

pp.72.2.1, (Released:2022-11-28)

参考文献数

33

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The present study examined long-term retention of learning of single alternate reward series in rats. Rats were given seven trials in a straight runway daily. During acquisition training of 16 days, Group SA (single alternate) received a series of seven trials of RNRNRNR (R: reward, N: non-reward) daily, whereas Group RD (random) was given presentation of either of RNRNNRR, RNNRRNR, RRNNRNR, or RRNRNNR in blocks of four days. After retention interval of 23 days, both groups were trained with a single alternate series of RNRNRNR as a test for 16 days. Anticipation of reward events in the series was indexed by slower running in non-rewarded trials than in rewarded trials. Although differentiation in running speed between rewarded and non-rewarded runs was not evident at the end of the acquisition training, Group SA developed reward-anticipation performance significantly faster than Group RD during the test. The results suggest that rats can retain learning of the single alternate series for a long period.

著者

山崎 由美子

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

vol.49, no.2, pp.107-137, 1999-12-25 (Released:2009-10-13)

参考文献数

125

被引用文献数

7 4

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The purpose of this paper is to review the researches on stimulus equivalence in nonhuman animals, based on the formulation by Sidman. Among the behavioral properties that he proposed as essential elements of stimulus equivalence, “reflexivity” has been confirmed in various species, and the evidence of “transitivity” has also been obtained in pigeons. However, “symmetry” seems much more difficult to be formed, and specifically, “equivalence” was shown only in a sea lion. On the other hand, stimulus equivalence also has been examined using procedures other than traditional conditional discrimination, or by many-to-one (MTO) matching-to-sample and Pavlovian conditioning. Recently, positive evidence was obtained in budgerigars, based on the interpretation that behavior, in addition to stimulus, should be included as a member of an equivalence class. These new approaches in research have suggested that equivalence may not be a behavioral ability that enables us to use language, but a basic cognitive function common to other animals. This proposition, indicating that equivalence is apt for comparative study, implies that the conventional research methods should be reexamined.

著者

瀧本 彩加

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

vol.65, no.1, pp.1-9, 2015 (Released:2015-06-13)

参考文献数

48

被引用文献数

4

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Prosocial behaviors have been considered a hallmark of humans in the past. However, accumulating experimental data in comparative cognitive science have revealed that nonhuman animals also show prosocial behaviors. Nevertheless, its evolutionary path has remained unclear despite a great deal of recent research effort. In this paper, I first review experimental studies on prosocial behaviors in nonhuman primates, by focusing on the influences of request behavior and social closeness. Then, I evaluate some factors that have been thought to play an important role in facilitating the convergent evolution of prosocial behaviors (inequity aversion, interdependence, tolerance) based on experimental data. I finally propose some possible future studies to explore the evolutionary path of prosocial behaviors, by referring to the previously discussed psychological mechanism that seems to support nonhuman primates’ prosocial behaviors (Yamamoto & Takimoto, 2012).

著者

佐藤 綾

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

vol.68, no.1, pp.89-97, 2018 (Released:2018-06-27)

参考文献数

49

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The guppy (Poecilia reticulata), a polyandrous livebearing fish, is a model organism in the study of sexual selection. This species exhibits sexual dimorphism, such as male body coloration (orange, black, or iridescence color spots). Although there is evidence of a preference for colorful males in female mate choice, a wide variation in male color patterns is found even in a population. Recently, there has been an increase in studies examining the postcopulatory processes involved in sperm competition and cryptic female choice in this species. If male traits that favor sperm competition and/or cryptic female choice correspond with traits preferred in female mate choice, then postcopulatory processes will reinforce the selection to colorful males. In contrast, if males with traits preferred by females are not favored by sperm competition and/or cryptic female choice, then postcopulatory processes will weaken the selection to colorful males. In this paper, I review studies of the relationships between male guppy coloration and female mate choice, sperm competition, and cryptic female choice, and discuss the possible factors that maintain the variation in male coloration.

著者

丸山 浩

出版者

The Japanese Society for Animal Psychology

雑誌

動物心理学年報 (ISSN:00035130)

巻号頁・発行日

vol.4, pp.61-68, 1954-04-25 (Released:2009-10-14)

参考文献数

9

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以上この実験では, cue-reversal techniqueを用いて弁別学習に於ける連続説と非連続説の対立を吟味したのであるが, 被験動物が異つたのみでその他の実験条件を等しくしながら, 連続説の期待に反して, 先行訓練の最終学習過程に及ぼす正又は負の波及を認めることは出来なかつた。連続説の側で得た結果との不一致は, ここでは, 位置習性の機構が, 単に位置に対する興奮傾向の優越にもとずくものでなく, 何等かの他の要因に基くことを暗示させる結果となつた。最後に実験結果そのものは非連続説の期待と一致したが, それだからといつて, このことから直ちにいわゆる解決前期の特徴的反応様式-例えば位置習性等-が動物の “仮説” を示すと断定することは困難であることが示された。従つてこの論争を解決する為には更に異つた手続による案験の結果をまつ必要がある。

著者

Keiichiro TSUJI Kiyoshi ISHII Takashi MATSUO Kazuaki KAWANO

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

vol.49, no.1, pp.1-18, 1999-06-20 (Released:2009-10-13)

参考文献数

41

被引用文献数

5 7

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The house musk shrew Suncus murinus has successfully been domesticated for laboratory use both in the United States and Japan. Animals of this species have been found to be useful for behavioural studies in comparative psychology and the related fields. This article dealt with basic characteristics, ecological modes, maintenance of laboratory shrews, basic patterns of behaviour, and assessment of the species as a laboratory animal for behavioural studies. Basic characteristics covered phylogenetic status, morphology, growth, sensory functions, and motor functions. Although its ecology has not yet b en systematically investigated due to the difficulties for observing animals in the wild, some findings on the seasonal and locational variations of the population density in its natural habitat were obtained on the basis of the result of trapping. Keeping and breeding the already domesticated animals in an artificial environment as well as domesticating wild-originating animals were described. Characteristics of the caravaning behaviour were mentioned in relation to its sensitive period, its formation patterns, and development of the sensory and motor functions. Those findings were discussed in connection with its adaptive significance. Also, characteristics of the reproductive behaviour were represented. Behavioural interaction between sexes is expected to determine mating outcome, since the female is an induced ovulator, having no ovarian, vaginal, or behavioural oestrus cycle. Sequential pattern of the behaviour was described with reference to the male's pacifying behaviours and the postejaculatory attack towards the partner female. Together with those two observations, the activity rhythm, aggressive and learning behaviours were mentioned. Lastly, this species was assessed as a laboratory animal for behavioural studies.

著者

小山 高正

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

vol.50, no.2, pp.255-259, 2000-12-25 (Released:2009-10-13)

参考文献数

10

著者

山本 知里

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

vol.69, no.2, pp.175-186, 2019 (Released:2019-12-18)

参考文献数

82

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Social intelligence hypotheses propose that complex socialization drives cognitive ability, which animals use to solve the problems associated with complex societies. However, studies of social intelligence have, so far, been limited to a few species, and further studies are needed to discuss "why" social intelligence has evolved in species that have adapted to various environments. Bottlenose dolphins are thought to have complex social systems and cognitive abilities. The evolution of their social intelligence in underwater environments is very different from that of terrestrial animals such as humans and apes. In this paper, we review several social intelligence studies of wild and captive bottlenose dolphins that encompass social interactions ― including affiliative, agonistic interactions and post-conflict affiliations ― and cognitive abilities ― including cooperation, prosocial behavior and joint attention. We also discuss further scope for research on the social intelligence of dolphins.

著者

高岡 祥子 森崎 礼子 藤田 和生

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

vol.63, no.2, pp.123-130, 2013 (Released:2013-12-17)

参考文献数

27

被引用文献数

3 3

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Previous studies suggest that nonhuman animals form concepts that integrate information from multiple sensory modalities such as vision and audition. For instance, Adachi, Kuwahata, and Fujita (2007) demonstrated that dogs form auditory-visual cross-modal representation of their owner. However, whether such multi-modal concepts would expand to more abstract, or collective, ones remains unknown. To answer the question, we tested whether dogs were sensitive to congruence of human genders suggested by the voice and the face of an unfamiliar person. We showed to the dogs a photograph of a male or female human face on the monitor after playing a voice of a person either matching or mismatching in gender. Dogs looked at the photograph for longer duration when the auditory stimuli were incongruent than when they were congruent; that is, expectancy violation was suggested. This result suggests that dogs spontaneously associate auditory and visual information to form a cross-modal concept of human gender. This is the first report showing that cross-modal representation in nonhuman animals expands to an abstract social category.

著者

井谷 美友 久保(川合) 南海子 川合 伸幸

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

vol.65, no.2, pp.63-69, 2015 (Released:2015-12-18)

参考文献数

16

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Studies on instrumental learning have rarely been conducted with tailed amphibians. This may be due primarily to difficulties in training newts with food rewards. Most previous studies on instrumental learning by newts have employed runways without a distinct discriminative stimulus associated with food. In this study, we trained newts (Cynops pyrrhogaster) with black rings as the discriminative stimuli at close distance (5 cm ahead). Two newts were trained to pass through one ring with a diameter of 8 cm. One newt failed to show evidence of learning (i.e., decreased response time) with 14 sessions of massed trials (4 trials/session). The second newt, however, learned to pass through rings with diameters of 8, 6, 5, and 4 cm. A 20-trial follow-up probe test was conducted with the second newt, in which the 4-cm black ring and a novel red square were presented side by side. The newt did not choose the black ring over the red square in any of the trials, suggesting that neither the black color nor the circle shape drove the newt’s behavior. In a retention test conducted 185 days later, the newt did not pass through the ring of 4 cm at all, suggesting that this behavior was learned but not retained after 6 months. Presentations of distinctive stimuli in close proximity might enhance appetitive instrumental learning by newts, which is otherwise difficult to accomplish using runway apparatuses with no distinctive cues to elicit instrumental behaviors.

著者

荒川 礼行 荒川 圭子

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

vol.73, no.2, pp.21-32, 2023 (Released:2023-12-25)

参考文献数

46

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Empirical studies on behavior using animal models provide irreplaceable tools for dissecting intricate neural circuits into multiple output modules that concomitantly regulate segmented components of behavior. Recent technical advancement in the manipulation and measurement of neural cell/circuit activities in freely behaving animals allow us to bridge the gap between neural processes and behavior expression. While neural signals are processed on the second timescales, the nature of behavior is time-consuming effort to gain interaction with environmental stimuli for adaptation. Therefore, a bundle of neural activities cannot simply represent entire behavioral processes, but rather segmented behavior components. Hence, we must reconsider how such bundles compose total outputs forming functional set of behavior, and thus, how integrated behavior can be broken into neural modular components, such as sensory detection, element recognition, behavior drive, and action/movement execution, by neural activity timescale units. Our refined protocol on behavioral studies is more effective in terms of determining what we observe in animal behavior and how we interpret neuro behavior relationship for vital contribution to basic and translational studies.

著者

大北 碧 永野 茜 領家 梨恵

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

vol.73, no.2, pp.33-34, 2023 (Released:2023-12-25)

参考文献数

3

著者

粟津 俊二 藤田 和生

出版者

THE JAPANESE SOCIETY FOR ANIMAL PSYCHOLOGY

雑誌

動物心理学研究 (ISSN:09168419)

巻号頁・発行日

vol.48, no.2, pp.183-190, 1998-12-15 (Released:2009-10-13)

参考文献数

18

被引用文献数

2 4

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ラット (観察者) は, ある食物を摂取してきた他個体 (提示者) と接触すると, その食物を選好するようになる。本研究では, 提示者と観察者の社会的関係の違いが, 伝達された食物に対する観察者の選好に影響を与えるかどうかを調べた。観察者を, 新奇な匂いのする異なった食物を摂取した2匹の提示者に接触させ, その後選択場面において, これら2つの食物に対する観察者の選好を測定した。観察者は, 既知の提示者が伝えた食物よりも未知の提示者が伝えた食物を選好し, また優位な提示者が伝えた食物よりも劣位な提示者が伝えた食物を選好した。この違いは, 観察者-提示者間の身体的な接触時間が異なるために生じたものではなかった。今回見られた選好は, ともにラットにとって適応的なものであると思われる。未知の提示者が伝えた食物を選好することは摂取する食物の幅を拡げ, 劣位な提示者が伝えた食物を選好することは食物獲得に要するコストを下げることにつながると考えられる。