Julia Fischer

German Primate Center | DPZ · Cognitive Ethology Laboratory

Objectives: Primate social systems are remarkably diverse, and thus play a central role in understanding social evolution, including the biological origin of human societies. Although baboons have been prominently featured in this context, historically little was known about the westernmost member of the genus, the Guinea baboon (Papio papio). Ma...

As humans age, they become more selective regarding their personal goals [1] and social partners [2]. Whereas the selectivity in goals has been attributed to losses in resources (e.g., physical strength) [3], the increasing focus on emotionally meaningful partners is, according to socioemotional selectivity theory, driven by the awareness of one's...

Trying to uncover the roots of human speech and language has been the premier motivation to study the signalling behaviour of nonhuman primates for several decades. Focussing on the question of whether we find evidence for linguistic reference in the production of nonhuman primate vocalizations, I will first discuss how the criteria used to diagnos...

One key question in social evolution is the identification of factors that promote the formation and maintenance of stable bonds between females and males beyond the mating context. Baboons lend themselves to examine this question, as they vary in social organisation and male-female association patterns. We report the results from the first systema...

Significance Recent theoretical approaches to understanding the evolution of cooperation point to a close link between spatial structure and cooperative tendencies and question the importance of kin relations. We here show that Guinea baboon males living in a multilevel society maintain strong male bonds, irrespective of relatedness, and exhibit lo...

Choosing the right partners can mean the difference between success or failure at a cooperative task. Several studies in captivity have explored the extent to which animals can identify characteristics that make individuals better or worse at completing a joint task and whether animals use such information when choosing partners, with mixed evidenc...

Background Access to critical resources, including food, water, or shelter, significantly determines individual fitness. As these resources are limited in most habitats, animals may employ strategies of landscape partitioning to mitigate the impact of direct resource competition. Territoriality may be regarded as an aggressive form of landscape par...

In human foraging societies, hunting skill is a male quality signal closely tied to reproductive success, because it serves to provision the family, connected households, and the wider community. However, the relationship between catching or sharing prey and male reproductive success remains largely unexplored in other primate taxa. Using the multi...

Social bonds can be a way for individuals to gain access to crucial resources and services that cannot be taken by force and are therefore subject to leverage. Bonds between the sexes can provide access to services that are specific to the other sex. Females exert leverage over males in terms of mating access, males have leverage over females in te...

While it is well established that apes invent or individually learn new gestures, cases of development and use of novel gestures in monkeys are more rarely described. We report a case of a novel, idiosyncratic gesture in a Barbary macaque (Macaca sylvanus) at 'La Forêt des Singes', Rocamadour, France. One adult male, Jomanix, was observed hand-clap...

In response to environmental and social challenges, animals mount physiological “stress responses” involving elevated glucocorticoid (GC) levels, which may have long-term consequences for health and survival. However, the degree to which social factors drive these physiological responses is likely modulated by a species’ social system, including so...

Social evaluation-inferring individual characteristics of others from their past behaviours-is an adaptive strategy that helps to inform social decisions. However, how nonhuman primates form and use impressions about others to select their social partners strategically is still unclear. In this study, we investigated whether Tonkean macaques, Macac...

When foraging, animals face decisions regarding unpredictable resources and varying predation risk, in which the cost-benefit trade-off must be assessed. Life-history theory focuses on resource allocation with regard to development and suggests there should be a variation in risk-taking propensity across age, manifested by a shift in goals from gai...

Anti-predator behavior allows to investigate how animals classify potential threats in their environment and which cognitive mechanisms might be involved in risk assessment. Snakes are common predators for many primate species, yet most of our knowledge on primate anti-snake behavior stems from predator model experiments. Few studies have investiga...

Recognizing skillful group members is crucial for making optimal social choices. Whether and how nonhuman animals attribute skill to others is still debated. Using a lever-operated food box, we enhanced the foraging skill of a single male ( the specialist ) in one zoo housed and two wild groups of Guinea baboon ( Papio papio ). We measured group me...

The “Seductive Allure of Neuroscience Explanations” (SANE) effect refers to the observation that superfluous neuroscience information (SNI) added to an explanation can bias judgments of information quality. This and other related findings have called for education measures that enhance the ability to distinguish good explanations from bad ones and...

Bonds, good and differentiated relationships, among group members have fitness benefits, also bonds among non-kin males and females. Here we explore from a deductive framework in what circumstances Between Sex Bonds (BSB) can be expected in multimale multi-female primate group. BSB are considered a way to access sources of power that are subject to...

There are hundreds of extant species of primate. Is it a coincidence that the only known species to develop fluid speech was part of the species-poor primate clade characterized by substantially greater relative body size? In this position paper, we discuss pertinent evidence from four species of American monkey, seven species of Afroeurasian monke...

Conservation funding is currently limited; cost-effective conservation solutions are essential. We suggest that the thousands of field stations worldwide can play key roles at the frontline of biodiversity conservation and have high intrinsic value. We assessed field stations’ conservation return on investment and explored the impact of COVID-19. W...

Social evaluations are a pervasive feature of human thinking. Studies on selective trust, selective social learning, and helping – that is, in cooperative contexts – have shown that children become competent social decision-makers in their preschool years. Choosing partners based on relevant attributes is equally important for success in competitiv...

1. Background. In many animal species, parents allocate resources to enhance offspring survival and thereby reproductive success ('parental investment'). The level of parental investment varies between species and individuals, and one critical question in behavioral ecology and evolution is to which degree variation in parental investment affects o...

We compared the risk preferences of long-tailed macaques (Macaca fascicularis) in a social and a nonsocial condition, where we assessed their preference for a safe or a risky option after repeated information sampling. To this end, we devised a food dispenser that could run automatically or involve a human distributor. Only two of the initial set o...

In socially living animals, relationships between group members are typically highly differentiated. Some dyads maintain strong and long-lasting relationships, while others are only connected by weak ties. There is growing evidence that the number and strength of social bonds are related to reproductive success and survival. Yet, few of these analy...

Research on the vocal behaviour of non-human primates is often motivated by a desire to understand the origins of semantic communication, which led to a partial separation of this research from ecological-evolutionary approaches. To bridge this gap, we returned to the textbook example of semantic communication in animals, the vervet monkey, Chloroc...

Baboons (genus Papio) are a morphologically and behaviorally diverse clade of catarrhine monkeys that have experienced hybridization between phenotypically and genetically distinct phylogenetic species. We used high-coverage whole-genome sequences from 225 wild baboons representing 19 geographic localities to investigate population genomics and int...

Comparing oneself to others is a key process in humans that allows individuals to gauge their performances and abilities and thus develop and calibrate their self-image. Little is known about its evolutionary foundations. A key feature of social comparison is the sensitivity to other individuals’ performance. Recent studies on primates produced equ...

Baboons (genus Papio ) are a morphologically and behaviorally diverse clade of catarrhine monkeys that have experienced hybridization between phenotypically and genetically distinct phylogenetic species. We used high coverage whole genome sequences from 225 wild baboons representing 19 geographic localities to investigate population genomics and in...

Protest in response to unequal reward distribution is thought to have played a central role in the evolution of human cooperation. Some animals refuse food and become demotivated when rewarded more poorly than a conspecific, and this has been taken as evidence that non-human animals, like humans, protest in the face of inequity. An alternative expl...

Comparing oneself to others is a key process in humans that allows individuals to gauge their performances and abilities and thus develop and calibrate their self-image. Very little is known about its evolutionary foundations. A key feature of social comparison is the sensitivity to other individuals’ performance. Recent studies on primates produce...

Many real-world decisions in social contexts are made while observing a partner's actions. To study dynamic interactions during such decisions, we developed a setup where two agents seated face-to-face engage in game-theoretical tasks on a shared transparent touchscreen display ('transparent games'). We compared human and macaque pairs in a transpa...

The steepness of dominance hierarchies provides information about the degree of competition within animal social groups and is thus an important concept in socioecology. The currently most widely used metrics to quantify steepness are based on David's scores (DS) derived from dominance interaction networks. One serious drawback of these DS‐based me...

Short-term memory is implicated in a range of cognitive abilities and is critical for understanding primate cognitive evolution. To investigate the effects of phylogeny, ecology and sociality on short-term memory, we tested the largest and most diverse primate sample to date (421 non-human primates across 41 species) in an experimental delayed-resp...

Wissenschaftler:innen gehören oft zu denjenigen Personen, die durch ihr Reiseverhalten in einem weit überdurchschnittlichen Maß zum Ausstoß von CO2-Emissionen beitragen, und zwar vor allem durch Flugreisen. Die zunehmende Internationalisierung der Wissenschaft ist an sich eine zu begrüßende Entwicklung. Aber Flugreisen können deutlich reduziert wer...

According to the Strength-and-Vulnerability-Integration (SAVI) model, older people are more motivated to avoid negative affect and high arousal than younger people. To explore the biological roots of this effect, we investigate communicative interactions and social information processing in Barbary macaques (Macaca sylvanus) living at ‘La Forêt des...

Researchers have studied non-human primate cognition along different paths, including social cognition, planning and causal knowledge, spatial cognition and memory, and gestural communication, as well as comparative studies with humans. This volume describes how primate cognition is studied in labs, zoos, sanctuaries, and in the field, bringing tog...

Researchers have studied non-human primate cognition along different paths, including social cognition, planning and causal knowledge, spatial cognition and memory, and gestural communication, as well as comparative studies with humans. This volume describes how primate cognition is studied in labs, zoos, sanctuaries, and in the field, bringing tog...

In group-living species, evolution puts a premium on the ability of individuals to track the state, whereabouts, and interactions of others. The value of social information might vary with the degree of competition within and between groups, however. We investigated male monitoring of female location in wild Guinea baboons (Papio papio). Guinea bab...

In the last decade, drones have become an affordable technology offering highly mobile aerial platforms that can carry a range of sensory equipment into hitherto uncharted areas. Drones have thus become a widely applicable tool for surveying animal populations and habitats to assist conservation efforts or to study the behavioural ecology of specie...

Male–male bonds may confer substantial fitness benefits. The adaptive value of these relationships is often attributed to coalitionary support, which aids in rank ascension and female defence, ultimately resulting in greater reproductive success. We investigated the link between male–male sociality and both coalitionary support and reproductive suc...

Male-male bonds may confer substantial fitness benefits. The adaptive value of these relationships is often attributed to coalitionary support, which aids in rank ascension and female defence, ultimately resulting in greater reproductive success. We investigated the link between male-male sociality and both coalitionary support and reproductive suc...

We investigate how the ability to respond appropriately to reasons provided in discourse develops in young children. In Study 1 (N = 58, Germany, 26 girls), 4‐ and 5‐, but not 3‐year‐old children, differentiated good from bad reasons. In Study 2 (N = 131, Germany, 64 girls), 4‐ and 5‐year‐old children considered both the strength of evidence for th...

According to the Strength-and-Vulnerability-Integration (SAVI) model, older people are more motivated to avoid negative affect and high arousal than younger ones. To explore the biological roots of this effect, we investigated communicative interactions and social information processing in Barbary macaques ( Macaca sylvanus ) living at ‘La Forêt de...

The steepness of dominance hierarchies provides information about the degree of competition within animal social groups and is thus an important concept in socioecology. The currently most widely-used metrics to quantify steepness are based on David's scores (DS) derived from dominance interaction networks. One serious drawback of these DS-based me...

Inequity aversion plays a central role in human cooperation. Some animals similarly show frustration and become demotivated when rewarded more poorly than a conspecific, which has been taken as evidence of inequity aversion. An alternative explanation - social disappointment - shifts the cause of frustration from the unequal reward to the human exp...

Collective movement of social groups requires coordination between individuals. When cohesion is imperative, consensus must be reached, and specific individuals may exert disproportionate influence during decision-making. Animals living in multi-level societies, however, often split into consistent social subunits during travel, which may impact gr...

Here we investigate how reason-responsiveness – the ability to respond appropriately to reasons provided in discourse – develops in young children. In Study 1 (N=58, 26 girls), 4- and 5- , but not 3-year-old children, differentiated good from bad reasons. In Study 2 (N=131, 64 girls), 4- and 5-year-old children considered both the strength of evide...

How learning affects vocalizations is a key question in the study of animal communication and human language. Parallel efforts in birds and humans have taught us much about how vocal learning works on a behavioural and neurobiological level. Subsequent efforts have revealed a variety of cases among mammals in which experience also has a major influ...

Visual bias in social cognition studies is often interpreted to indicate preference, yet it is difficult to elucidate whether this translates to social preference. Moreover, visual bias is often framed in terms of surprise or recognition. It is thus important to examine whether an interpretation of preference is warranted in looking time studies. H...

Aging brings about notable changes in sociality, with an increasing focus on essential partners in both humans and nonhuman primates. Several studies have shown that older nonhuman primates have fewer social partners and shift their types of interactions. The majority of these studies, however, involved only female individuals. Much less is known a...

Thorough knowledge of the ecology of a species or population is an essential prerequisite for understanding the impact of ecology on the evolution of their respective social systems. Because of their diversity of social organizations, baboons (Papio spp.) are a useful model for comparative studies. Comparative ecological information was missing for...

Replication is an important tool used to test and develop scientific theories. Areas of biomedical and psychological research have experienced a replication crisis, in which many published findings failed to replicate. Following this, many other scientific disciplines have been interested in the robustness of their own findings. This chapter examin...

A Correction to this paper has been published: https://doi.org/10.1007/s00265-021-02993-7

Social comparisons are a fundamental feature of human thinking and affect self-evaluations and task performance. Little is known about the evolutionary origins of social comparison processes, however. Previous studies that investigated performance-based social comparisons in nonhuman primates yielded mixed results. We report three experiments that...

This protocol provides a standardized methodology for the analyses of genetic relatedness and paternity assignment in wild Guinea baboons (Papio papio) based on 24 microsatellite markers. It describes all methodological steps from sample collection and storage, DNA extraction, microsatellite amplification, and genotyping to a detailed explanation o...

Studies of nonhuman primate communication are often motivated by the desire to shed light on the evolution of speech. In contrast to human speech, the vocal repertoires of nonhuman primates are evolutionarily highly conserved. Within species-specific constraints, calls may vary in relation to the internal state of the caller or social experience. R...

Male-male social relationships in group-living mammals vary from fierce competition to the formation of opportunistic coalitions or the development of long-lasting bonds. We investigated male-male relationships in Guinea baboons ( Papio papio ), a species characterized by male-male tolerance and affiliation. Guinea baboons live in a multi-level soc...

The extent to which nonhuman primate vocalizations are amenable to modification through experience is relevant for understanding the substrate from which human speech evolved. We examined the vocal behaviour of Guinea baboons, Papio papio, ranging in the Niokolo Koba National Park in Senegal. Guinea baboons live in a multi-level society, with units...

Microsatellite genotyping is an important genetic method for a number of research questions in biology. Given that the traditional fragment length analysis using polyacrylamide gel or capillary electrophoresis has several drawbacks, microsatellite genotyping‐by‐sequencing (GBS) has arisen as a promising alternative. Although GBS mitigates many of t...

Across the lifespan, the performance in problem-solving tasks varies strongly, owing to age-related variation in cognitive abilities as well as the motivation to engage in a task. Non-human primates provide an evolutionary perspective on human cognitive and motivational ageing, as they lack an insight into their own limited lifetime, and ageing tra...

Most statistical problems encountered throughout life require the ability to quantify probabilities based on proportions. Recent findings on the early ontogeny of this ability have been mixed: For example, when presented with jars containing preferred and less preferred items, 12-month-olds, but not 3- and 4-years-olds, seem to rely on the proporti...

Scientific disciplines face concerns about replicability and statistical inference, and these concerns are also relevant in animal cognition research. This paper presents a first attempt to assess how researchers make and publish claims about animal physical cognition, and the statistical inferences they use to support them. We surveyed 116 publish...

Following the expanding use and applications of virtual reality in everyday life, realistic virtual stimuli are of increasing interest in cognitive studies. They allow for control of features such as gaze, expression, appearance, and movement, which may help to overcome limitations of using photographs or video recordings to study social responses....

To balance the trade-offs of male co-residence, males living in multi-male groups may exchange ritualized greetings. Although these non-aggressive signals are widespread in the animal kingdom, the repertoire described in the genus Papio is exceptional, involving potentially harmful behaviours such as genital fondling. Such greetings are among the m...

Against the background of the seminal papers on the vervet monkey alarm call system by Seyfarth, Cheney and Marler (1980a. 1980b), I provide an overview of context specificity in calling and call comprehension learning in the genus Chlorocebus, and to which degree these findings inform the reconstruction of the evolution of speech and language. The...

Multilevel societies (MLSs), stable nuclear social units within a larger collective encompassing multiple nested social levels, occur in several mammalian lineages. Their architectural complexity and size impose specific demands on their members requiring adaptive solutions in multiple domains. The functional significance of MLSs lies in their memb...