Journal of Comparative Psychology

Learned bird songs often have a hierarchical organization. In the case of zebra finches, each bird's song is made up of a string of notes delivered in a stereotyped sequence to form a "motif," and motifs are repeated to form a song bout. During song learning, young males copy "chunks" of two or more consecutive notes from their tutors' songs. These chunks are represented as distinct units within memory (during learning) and within motor systems (during song production). During song performance, motifs may deviate from the learned sequence by stopping short, starting late, or by skipping, inserting, or repeating notes...

Executive function (EF) involves several abilities often correlated with success in various aspects of human life. Similar skills could also be advantageous to nonhumans, but few studies have effectively examined the extent of their EF abilities. Studies have also examined what experiences might strengthen/weaken human EF; might specific experiences also affect nonhuman EF? One type of EF often tested in both humans and nonhumans involves a delay of gratification-the ability to forgo an immediate reward to gain one either better in quality or quantity...

Impulsivity is a critical component of dog ( Canis familiaris ) behavior that owners often want to curtail. Though studies of dog impulsivity have examined their inability to wait and to inhibit inappropriate behaviors, it is not clear whether impulsivity is a behavioral trait with consistent characteristics across contexts. For this project, we conducted a systematic review and meta-analysis to investigate whether impulsivity exists as a behavioral trait in domestic dogs. Under a preregistered protocol, we processed over 10,000 bibliographic database records to uncover 13 articles with multiple impulsivity tasks assessed in the same subjects...

Humans anthropomorphize: as a result of our evolved ultrasociality, we see the world through person-colored glasses. In this review, I suggest that an interesting proportion of the extraordinary tool-using abilities shown by humans results from our mistakenly anthropomorphizing and forming social relationships with objects and devices. I introduce the term machination to describe this error, sketch an outline of the evidence for it, tie it to intrinsic reward for social interaction, and use it to help explain overimitation-itself posited as underpinning human technological complexity-by human children and adults...

Many animals respond to and use social cues emitted by other species (e.g., head direction). In the context of human-animal communication, these capacities have been attributed to regular and longstanding exposure to humans. We presented wild brown skuas (Catharacta antarctica ssp. lonnbergi) with two versions of an object-choice paradigm. In the cooperative version (Experiment 1), one human experimenter provided a simple and salient cue indicating which of two containers covered a food reward. The cues administered consisted of touching, looking at, pointing at, or pointing and looking at the container hiding food...

Individuals in social groups can gain benefits from being in those groups, including an increased ability to find food and avoid predators. We tested for potential group benefits in shelter choice in the Argentinian wood roach, Blaptica dubia. Roaches were tested in arenas with two shelters available in which one shelter was significantly darker than the other. Female and male roaches, housed separately, were tested as solitary individuals, or in same-sex groups of 5, 10, or 15. The roaches were tested under two light regimes (lights on vs...

In a successive delay-discounting task, a small reward can be obtained immediately but a larger reward can be obtained if one waits. There is evidence that the larger reward can be obtained more easily if one is "distracted" from obtaining the small reward. It is proposed here that a distractor stimulus may function as a Pavlovian conditioned stimulus (sign tracking) because orienting to it may be directly associated with the larger reinforcer. In the present study with pigeons, we examined two successive procedures: (a) a peck to a red light resulted in one pellet of food, and waiting for the red light to turn off resulted in five pellets (Red-Only)...

In this essay, the author explores the question of why distractions sometimes aid self-control. In a study with chimpanzees, Evans and Beran (2007) used two conditions with toys to address the possibility raised by Mueller et al. (2023) about toys as distractors. In the first, the accumulating rewards were within reach, and so chimpanzees had to inhibit taking rewards if more were to accumulate. The second condition was essential to this issue, as in that case toys also were available, but the delayed reward was out of reach (i...

Within human-animal dyadic interactions, dog-human gaze has been identified as the crux of several important visual behaviors, such as looking back, gaze-following, and participation in an oxytocin feedback loop. It has been posited that this gaze behavior may have been motivated and sustained by cooperative relationships between dogs ( Canis lupus familiaris ) and humans (e.g., hunting, service roles), however, to investigate why gaze evolved, a comparison to a domesticated species that lacks a protracted history of cooperative companionship is needed: the domestic cat ( Felis catus )...

Individual recognition underlies social behaviors in many species and is essential for complex social interactions commonly occurring between conspecifics. Focusing on visual perception, we explored this process in African grey parrots ( Psittacus erithacus ) using the matching-to-sample (MTS) method commonly used in primate research. We used cards made from photographs of familiar conspecific in four consecutive experiments, first testing the ability of our subjects (two male and one female adult) to match the photographs of familiar individuals and then creating modified stimuli cards to determine which visual aspects and features were crucial for successful recognition of a familiar conspecific...

Logical inference is often assumed a human-unique ability, although many species of apes and monkeys have shown some facility within a two-cup task in which one cup is baited, the primate is shown the cup which is empty (an exclusion cue), and subsequently chooses the other baited cup. In published reports, New World monkey species show a limited ability to choose successfully, often with half or more of the subjects tested not showing the ability with auditory cues or with exclusion cues. In this study, five cotton-top tamarins ( Saguinus oedipus ) were tested in a two-cup task with visual or auditory cues which revealed the presence or absence of bait, and in a second study, were tested with a four-cup array using a variety of walls to define the baiting space and a variety of visual cues including inclusion and exclusion...

Chunking is an important cognitive process allowing the compression of information in short-term memory. The aim of this study is to compare the dynamics of chunking during the learning of a visuomotor sequence in humans ( Homo sapiens ) and Guinea baboons ( Papio papio ). We duplicated in humans an experimental paradigm that has been used previously in baboons. On each trial, human participants had to point to a moving target on a touch screen. The experiment involved the repetition of the same sequence of nine items over a 1,000 trials...

Primate facial musculature enables a wide variety of movements during bouts of communication, but how these movements contribute to signal construction and repertoire size is unclear. The facial mobility hypothesis suggests that morphological constraints shape the evolution of facial repertoires: species with higher facial mobility will produce larger and more complex repertoires. In contrast, the socio-ecological complexity hypothesis suggests that social needs shape the evolution of facial repertoires: as social complexity increases, so does communicative repertoire size...

"How" an action is performed is not solely determined by biomechanical constraints, but it depends on the agent's intention, that is, "why" the action is performed. Recent findings suggest that intentions can be specified at a tangible and quantifiable level in the kinematics of movements; that is, different motor intentions translate into different kinematic patterns. In the present study, we used 3D kinematical analysis to investigate whether the organization of climbing plants' approach-to-grasp action is sensitive to the kind of intention driving their movement toward potential support, namely individual or social...

Many argue that the animal understanding of human referential communication is a by-product of domestication. However, the domestication hypothesis is not unanimously supported as some nondomesticated species such as sea lions, dolphins, or African elephants perform well in the understanding of human pointing gesture. There is a need to study species with different levels of domestication across different taxa to understand the emerging communicative sociocognitive skills in animals that provide them with the ability to comprehend human-given cues...

The evidence of "cognitive impenetrability" is a byproduct of the fact that minds often must react quickly to sensory stimulation, and they must attempt to make visual stimuli meaningful given what the perceiver knows of the world. Hanus et al. remind us that such immediate decisions may, in fact, help keep us alive, but at the possible cost of sometimes misaligning visual perception and physical reality. That said, not all people fall prey to all illusions, and many individuals may only fall prey to some illusions, but not others...

Despite increasing numbers of publications showing that many animals possess the neural substrates involved in emotions and consciousness and exhibit agency in their behavior, many animals are still restrained and forced to take part in applied or fundamental research. However, these restraints and procedures, because they stress animals and limit the expression of adaptive behavior, may result in compromised findings. Researchers should alter their research paradigms to understand the mechanisms and functions of the brain and behavior so that the paradigms incorporate animals' agency...

The cap-pushing response (CPR) is a new free-flying technique used to study learning and memory in honey bees. Bees fly to a target where they push a cap to reveal a hidden food source. When combined with traditional odor and color targets, the CPR technique opens the door to additional choice preference tests in honey bees. To facilitate the use of the CPR technique, three experiments were conducted. Experiment 1 investigates the impact of extended training on the CPR response and its role in extinction. Experiment 2 explores the role of CPR in overshadowing, and Experiment 3 explores the effects of electric shock punishment on the CPR technique...

A wide range of nonhuman animal species has been shown to be able to respond to human referential signals, such as pointing gestures. The aim of the present study was to replicate previous findings showing cats to be sensitive to human pointing cues (Miklósi et al., 2005). In our study, we presented two types of human pointing gestures-momentary ipsilateral (direct pointing) and momentary cross-body pointing. We tested nine rescue cats in a two-way object-choice task. On a group level, the success rate of cats was 74...

Recent psychophysical experiments have shown that zebra finches (Taeniopygia guttata-a songbird) are surprisingly insensitive to syllable sequence changes in their species-specific motifs while budgerigars (Melopsittacus undulatus-a psittacine) do much better when tested on exactly the same sounds. This is unexpected since zebra finch males learn the order of syllables in their songs when young and sing the same song throughout adulthood. Here we probe the limits of this species difference by testing birds on an order change involving just two syllables, hereafter called bi-syllable phrases...