1
|
Felsche E, Völter CJ, Herrmann E, Seed AM, Buchsbaum D. How can I find what I want? Can children, chimpanzees and capuchin monkeys form abstract representations to guide their behavior in a sampling task? Cognition 2024; 245:105721. [PMID: 38262272 DOI: 10.1016/j.cognition.2024.105721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 12/23/2023] [Accepted: 01/10/2024] [Indexed: 01/25/2024]
Abstract
concepts are a powerful tool for making wide-ranging predictions in new situations based on little experience. Whereas looking-time studies suggest an early emergence of this ability in human infancy, other paradigms like the relational match to sample task often fail to detect abstract concepts until late preschool years. Similarly, non-human animals show difficulties and often succeed only after long training regimes. Given the considerable influence of slight task modifications, the conclusiveness of these findings for the development and phylogenetic distribution of abstract reasoning is debated. Here, we tested the abilities of 3 to 5-year-old children, chimpanzees, and capuchin monkeys in a unified and more ecologically valid task design based on the concept of "overhypotheses" (Goodman, 1955). Participants sampled high- and low-valued items from containers that either each offered items of uniform value or a mix of high- and low-valued items. In a test situation, participants should switch away earlier from a container offering low-valued items when they learned that, in general, items within a container are of the same type, but should stay longer if they formed the overhypothesis that containers bear a mix of types. We compared each species' performance to the predictions of a probabilistic hierarchical Bayesian model forming overhypotheses at a first and second level of abstraction, adapted to each species' reward preferences. Children and, to a more limited extent, chimpanzees demonstrated their sensitivity to abstract patterns in the evidence. In contrast, capuchin monkeys did not exhibit conclusive evidence for the ability of abstract knowledge formation.
Collapse
Affiliation(s)
- Elisa Felsche
- School of Psychology and Neuroscience, University of St Andrews, Scotland, UK; Department of Comparative Cultural Psychology, Max Planck Institute for Evolutionary Anthropology, Germany.
| | - Christoph J Völter
- School of Psychology and Neuroscience, University of St Andrews, Scotland, UK; Department of Comparative Cultural Psychology, Max Planck Institute for Evolutionary Anthropology, Germany; Comparative Cognition, Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University of Vienna and University of Vienna, Vienna, Austria.
| | | | - Amanda M Seed
- School of Psychology and Neuroscience, University of St Andrews, Scotland, UK.
| | - Daphna Buchsbaum
- The Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, USA.
| |
Collapse
|
2
|
Bastos APM. Crows make optimal choices based on relative probabilities. Learn Behav 2023:10.3758/s13420-023-00612-1. [PMID: 37945911 DOI: 10.3758/s13420-023-00612-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2023] [Indexed: 11/12/2023]
Abstract
A recent study by Johnston, Brecht, and Nieder (2023, Current Biology, 33, 3238-3243) finds that carrion crows associate varying rates of reinforcement with novel arbitrary stimuli and make optimal decisions when they must later choose between stimulus pairs. These results demonstrate that crows are capable of not only storing information about reward probabilities in their memory but also making optimal choices based on this information even a month later.
Collapse
Affiliation(s)
- Amalia P M Bastos
- Department of Psychological & Brain Sciences, Johns Hopkins University, Baltimore, MD, USA.
| |
Collapse
|
3
|
Johnston M, Brecht KF, Nieder A. Crows flexibly apply statistical inferences based on previous experience. Curr Biol 2023; 33:3238-3243.e3. [PMID: 37369211 DOI: 10.1016/j.cub.2023.06.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/05/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023]
Abstract
Statistical inference, the ability to use limited information to draw conclusions about the likelihood of an event, is critical for decision-making during uncertainty. The ability to make statistical inferences was thought to be a uniquely human skill requiring verbal instruction and mathematical reasoning.1 However, basic inferences have been demonstrated in both preliterate and pre-numerate individuals,2,3,4,5,6,7 as well as non-human primates.8 More recently, the ability to make statistical inferences has been extended to members outside of the primate lineage in birds.9,10 True statistical inference requires subjects use relative rather than absolute frequency of previously experienced events. Here, we show that crows can relate memorized reward probabilities to infer reward-maximizing decisions. Two crows were trained to associate multiple reward probabilities ranging from 10% to 90% to arbitrary stimuli. When later faced with the choice between various stimulus combinations, crows retrieved the reward probabilities associated with individual stimuli from memory and used them to gain maximum reward. The crows showed behavioral distance and size effects when judging reward values, indicating that the crows represented probabilities as abstract magnitudes. When controlling for absolute reward frequency, crows still made reward-maximizing choices, which is the signature of true statistical inference. Our study provides compelling evidence of decision-making by relative reward frequency in a statistical inference task.
Collapse
Affiliation(s)
- Melissa Johnston
- Animal Physiology Unit, Institute of Neurobiology, University of Tübingen, 72076 Tübingen, Germany.
| | - Katharina F Brecht
- Animal Physiology Unit, Institute of Neurobiology, University of Tübingen, 72076 Tübingen, Germany
| | - Andreas Nieder
- Animal Physiology Unit, Institute of Neurobiology, University of Tübingen, 72076 Tübingen, Germany.
| |
Collapse
|
4
|
Caicoya AL, Colell M, Amici F. Giraffes make decisions based on statistical information. Sci Rep 2023; 13:5558. [PMID: 37142606 PMCID: PMC10160108 DOI: 10.1038/s41598-023-32615-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 03/30/2023] [Indexed: 05/06/2023] Open
Abstract
The ability to make inferences based on statistical information has so far been tested only in animals having large brains in relation to their body size, like primates and parrots. Here we tested if giraffes (Giraffa camelopardalis), despite having a smaller relative brain size, can rely on relative frequencies to predict sampling outcomes. We presented them with two transparent containers filled with different quantities of highly-liked food and less-preferred food. The experimenter covertly drew one piece of food from each container, and let the giraffe choose between the two options. In the first task, we varied the quantity and relative frequency of highly-liked and less-preferred food pieces. In the second task, we inserted a physical barrier in both containers, so giraffes only had to take into account the upper part of the container when predicting the outcome. In both tasks giraffes successfully selected the container more likely to provide the highly-liked food, integrating physical information to correctly predict sampling information. By ruling out alternative explanations based on simpler quantity heuristics and learning processes, we showed that giraffes can make decisions based on statistical inferences.
Collapse
Affiliation(s)
- Alvaro L Caicoya
- Department of Clinical Psychology and Psychobiology, Faculty of Psychology, University of Barcelona, Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, Barcelona, Spain
| | - Montserrat Colell
- Department of Clinical Psychology and Psychobiology, Faculty of Psychology, University of Barcelona, Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, Barcelona, Spain
| | - Federica Amici
- Research Group Human Biology and Primate Cognition, Institute of Biology, University of Leipzig, Leipzig, Germany.
- Department of Comparative Cultural Psychology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
| |
Collapse
|
5
|
Felsche E, Stevens P, Völter CJ, Buchsbaum D, Seed AM. Evidence for abstract representations in children but not capuchin monkeys. Cogn Psychol 2023; 140:101530. [PMID: 36495840 DOI: 10.1016/j.cogpsych.2022.101530] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 10/02/2022] [Accepted: 11/23/2022] [Indexed: 12/12/2022]
Abstract
The use of abstract higher-level knowledge (also called overhypotheses) allows humans to learn quickly from sparse data and make predictions in new situations. Previous research has suggested that humans may be the only species capable of abstract knowledge formation, but this remains controversial. There is also mixed evidence for when this ability emerges over human development. Kemp et al. (2007) proposed a computational model of how overhypotheses could be learned from sparse examples. We provide the first direct test of this model: an ecologically valid paradigm for testing two species, capuchin monkeys (Sapajus spp.) and 4- to 5-year-old human children. We presented participants with sampled evidence from different containers which suggested that all containers held items of uniform type (type condition) or of uniform size (size condition). Subsequently, we presented two new test containers and an example item from each: a small, high-valued item and a large but low-valued item. Participants could then choose from which test container they would like to receive the next sample - the optimal choice was the container that yielded a large item in the size condition or a high-valued item in the type condition. We compared performance to a priori predictions made by models with and without the capacity to learn overhypotheses. Children's choices were consistent with the model predictions and thus suggest an ability for abstract knowledge formation in the preschool years, whereas monkeys performed at chance level.
Collapse
Affiliation(s)
- Elisa Felsche
- School of Psychology and Neuroscience, University of St Andrews, Scotland; Department of Comparative Cultural Psychology, Max Planck Institute for Evolutionary Anthropology, Germany.
| | | | - Christoph J Völter
- Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University of Vienna and University of Vienna, Austria
| | - Daphna Buchsbaum
- Department of Cognitive, Linguistic and Psychological Sciences, Brown University, USA
| | - Amanda M Seed
- School of Psychology and Neuroscience, University of St Andrews, Scotland
| |
Collapse
|
6
|
Gualtieri S, Attisano E, Denison S. Young children’s use of probabilistic reliability and base-rates in decision-making. PLoS One 2022; 17:e0268790. [PMID: 35613117 PMCID: PMC9132303 DOI: 10.1371/journal.pone.0268790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 05/08/2022] [Indexed: 11/19/2022] Open
Abstract
Children are skilled reasoners who readily use causal, reliability, and base-rate (i.e., prior probability) information in their decisions. Though these abilities are typically studied in isolation, children often must consider multiple pieces of information to make an informed decision. Four experiments (N = 320) explored the development of children’s ability to use reliability and base-rate information when making decisions about draw outcomes. Experiment 1 examined the age at which children can first compare and choose between probabilistically reliable machines. Three- and 4-year-old children saw machines that were probabilistically reliable at obtaining objects while sampling from uniform distributions (i.e., all target or non-target objects). Although 4-year-old children correctly used reliability in their decisions, 3-year-olds did not. In Experiment 2a, 4- to 6-year-olds were presented with the same probabilistically reliable machines, although they sampled from a mixture of target and non-target items. Here, children tended to choose the machine with the better proportion of targets, regardless of reliability. This was replicated in Experiment 2b. In Experiment 3, children were presented with one perfectly reliable machine and one probabilistically unreliable machine. Here, children continued to mostly choose the machine with the better proportion of targets. These results raise questions about base-rate overuse early in development and highlight the need for additional work on children’s ability to use multiple pieces of information in decision-making.
Collapse
Affiliation(s)
- Samantha Gualtieri
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
| | - Elizabeth Attisano
- Department of Psychology, University of Waterloo, Waterloo, Ontario, Canada
| | - Stephanie Denison
- Department of Psychology, University of Waterloo, Waterloo, Ontario, Canada
| |
Collapse
|
7
|
Schulze C, Hertwig R. A description-experience gap in statistical intuitions: Of smart babies, risk-savvy chimps, intuitive statisticians, and stupid grown-ups. Cognition 2021; 210:104580. [PMID: 33667974 DOI: 10.1016/j.cognition.2020.104580] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 12/10/2020] [Accepted: 12/24/2020] [Indexed: 11/26/2022]
Abstract
Comparison of different lines of research on statistical intuitions and probabilistic reasoning reveals several puzzling contradictions. Whereas babies seem to be intuitive statisticians, surprisingly capable of statistical learning and inference, adults' statistical inferences have been found to be inconsistent with the rules of probability theory and statistics. Whereas researchers in the 1960s concluded that people's probability updating is "conservatively" proportional to normative predictions, probability updating research in the 1970s suggested that people are incapable of following Bayes's rule. And whereas animals appear to be strikingly risk savvy, humans often seem "irrational" when dealing with probabilistic information. Drawing on research on the description-experience gap in risky choice, we integrate and systematize these findings from disparate fields of inquiry that have, to date, operated largely in parallel. Our synthesis shows that a key factor in understanding inconsistencies in statistical intuitions research is whether probabilistic inferences are based on symbolic, abstract descriptions or on the direct experience of statistical information. We delineate this view from other conceptual accounts, consider potential mechanisms by which attributes of first-hand experience can facilitate appropriate statistical inference, and identify conditions under which they improve or impair probabilistic reasoning. To capture the full scope of human statistical intuition, we conclude, research on probabilistic reasoning across the lifespan, across species, and across research traditions must bear in mind that experience and symbolic description of the world may engage systematically distinct cognitive processes.
Collapse
Affiliation(s)
- Christin Schulze
- Center for Adaptive Rationality, Max Planck Institute for Human Development, Berlin, Germany.
| | - Ralph Hertwig
- Center for Adaptive Rationality, Max Planck Institute for Human Development, Berlin, Germany
| |
Collapse
|
8
|
Romain A, Broihanne MH, De Marco A, Ngoubangoye B, Call J, Rebout N, Dufour V. Non-human primates use combined rules when deciding under ambiguity. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190672. [PMID: 33423632 DOI: 10.1098/rstb.2019.0672] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Decision outcomes in unpredictable environments may not have exact known probabilities. Yet the predictability level of outcomes matters in decisions, and animals, including humans, generally avoid ambiguous options. Managing ambiguity may be more challenging and requires stronger cognitive skills than decision-making under risk, where decisions involve known probabilities. Here we compare decision-making in capuchins, macaques, orangutans, gorillas, chimpanzees and bonobos in risky and ambiguous contexts. Subjects were shown lotteries (a tray of potential rewards, some large, some small) and could gamble a medium-sized food item to obtain one of the displayed rewards. The odds of winning and losing varied and were accessible in the risky context (all rewards were visible) or partially available in the ambiguous context (some rewards were covered). In the latter case, the level of information varied from fully ambiguous (individuals could not guess what was under the covers) to predictable (individuals could guess). None of the species avoided gambling in ambiguous lotteries and gambling rates were high if at least two large rewards were visible. Capuchins and bonobos ignored the covered items and gorillas and macaques took the presence of potential rewards into account, but only chimpanzees and orangutans could consistently build correct expectations about the size of the covered rewards. Chimpanzees and orangutans combined decision rules according to the number of large visible rewards and the level of predictability, a process resembling conditional probabilities assessment in humans. Despite a low sample size, this is the first evidence in non-human primates that a combination of several rules can underlie choices made in an unpredictable environment. Our finding that non-human primates can deal with the uncertainty of an outcome when exchanging one food item for another is a key element to the understanding of the evolutionary origins of economic behaviour. This article is part of the theme issue 'Existence and prevalence of economic behaviours among non-human primates'.
Collapse
Affiliation(s)
- A Romain
- Université de Strasbourg, Strasbourg, France
| | - M-H Broihanne
- Laboratoire de Recherche en Gestion et Economie, EM Strasbourg Business School, Université de Strasbourg, Strasbourg, France
| | - A De Marco
- Fondazione Ethoikos, Radicondoli, Italy.,Parco Faunistico di Piano dell'Abatino, Poggio San Lorenzo, Italy
| | | | - J Call
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK.,Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - N Rebout
- PRC, UMR 7247, Cognitive and social ethology team, INRAE-CNRS-IFCE, University of Tours, Tours, France
| | - V Dufour
- PRC, UMR 7247, Cognitive and social ethology team, INRAE-CNRS-IFCE, University of Tours, Tours, France
| |
Collapse
|
9
|
Janmaat KRL. What animals do not do or fail to find: A novel observational approach for studying cognition in the wild. Evol Anthropol 2019; 28:303-320. [PMID: 31418959 PMCID: PMC6916178 DOI: 10.1002/evan.21794] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Revised: 06/17/2019] [Accepted: 07/12/2019] [Indexed: 12/29/2022]
Abstract
To understand how our brain evolved and what it is for, we are in urgent need of knowledge about the cognitive skills of a large variety of animal species and individuals, and their relationships to rapidly disappearing social and ecological conditions. But how do we obtain this knowledge? Studying cognition in the wild is a challenge. Field researchers (and their study subjects) face many factors that can easily interfere with their variables of interest. Although field studies of cognition present unique challenges, they are still invaluable for understanding the evolutionary drivers of cognition. In this review, I discuss the advantages and urgency of field-based studies on animal cognition and introduce a novel observational approach for field research that is guided by three questions: (a) what do animals fail to find?, (b) what do they not do?, and (c) what do they only do when certain conditions are met? My goal is to provide guidance to future field researchers examining primate cognition.
Collapse
Affiliation(s)
- Karline R. L. Janmaat
- Max Planck Institute for Evolutionary AnthropologyLeipzigGermany
- Institute for Biodiversity and Ecosystem DynamicsUniversity of AmsterdamAmsterdamThe Netherlands
| |
Collapse
|
10
|
Placì S, Padberg M, Rakoczy H, Fischer J. Long-tailed macaques extract statistical information from repeated types of events to make rational decisions under uncertainty. Sci Rep 2019; 9:12107. [PMID: 31431638 PMCID: PMC6702217 DOI: 10.1038/s41598-019-48543-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 07/22/2019] [Indexed: 11/09/2022] Open
Abstract
Human children and apes seem to be intuitive statisticians when making predictions from populations of objects to randomly drawn samples, whereas monkeys seem not to be. Statistical reasoning can also be investigated in tasks in which the probabilities of different possibilities must be inferred from relative frequencies of events, but little is known about the performance of nonhuman primates in such tasks. In the current study, we investigated whether long-tailed macaques extract statistical information from repeated types of events to make predictions under uncertainty. In each experiment, monkeys first experienced the probability of rewards associated with different factors separately. In a subsequent test trial, monkeys could then choose between the different factors presented simultaneously. In Experiment 1, we tested whether long-tailed macaques relied on probabilities and not on a comparison of absolute quantities to make predictions. In Experiment 2 and 3 we varied the nature of the predictive factors and the complexity of the covariation structure between rewards and factors. Results indicate that long-tailed macaques extract statistical information from repeated types of events to make predictions and rational decisions under uncertainty, in more or less complex scenarios. These findings suggest that the presentation format affects the monkeys’ statistical reasoning abilities.
Collapse
Affiliation(s)
- Sarah Placì
- Cognitive Ethology Laboratory, German Primate Center, Kellnerweg 4, 37077, Göttingen, Germany. .,Department of Developmental Psychology, University of Göttingen, Waldweg 26, 37073, Göttingen, Germany. .,Leibniz ScienceCampus Primate Cognition, German Primate Center, Kellnerweg 4, 37077, Göttingen, Germany.
| | - Marie Padberg
- Cognitive Ethology Laboratory, German Primate Center, Kellnerweg 4, 37077, Göttingen, Germany.,Leibniz ScienceCampus Primate Cognition, German Primate Center, Kellnerweg 4, 37077, Göttingen, Germany
| | - Hannes Rakoczy
- Department of Developmental Psychology, University of Göttingen, Waldweg 26, 37073, Göttingen, Germany.,Leibniz ScienceCampus Primate Cognition, German Primate Center, Kellnerweg 4, 37077, Göttingen, Germany
| | - Julia Fischer
- Cognitive Ethology Laboratory, German Primate Center, Kellnerweg 4, 37077, Göttingen, Germany.,Leibniz ScienceCampus Primate Cognition, German Primate Center, Kellnerweg 4, 37077, Göttingen, Germany
| |
Collapse
|
11
|
De Petrillo F, Rosati AG. Ecological rationality: Convergent decision-making in apes and capuchins. Behav Processes 2019; 164:201-213. [DOI: 10.1016/j.beproc.2019.05.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 05/02/2019] [Accepted: 05/08/2019] [Indexed: 02/07/2023]
|
12
|
Denison S, Xu F. Infant Statisticians: The Origins of Reasoning Under Uncertainty. PERSPECTIVES ON PSYCHOLOGICAL SCIENCE 2019; 14:499-509. [PMID: 31185184 DOI: 10.1177/1745691619847201] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Humans frequently make inferences about uncertain future events with limited data. A growing body of work suggests that infants and other primates make surprisingly sophisticated inferences under uncertainty. First, we ask what underlying cognitive mechanisms allow young learners to make such sophisticated inferences under uncertainty. We outline three possibilities, the logic, probabilistic, and heuristics views, and assess the empirical evidence for each. We argue that the weight of the empirical work favors the probabilistic view, in which early reasoning under uncertainty is grounded in inferences about the relationship between samples and populations as opposed to being grounded in simple heuristics. Second, we discuss the apparent contradiction between this early-emerging sensitivity to probabilities with the decades of literature suggesting that adults show limited use of base-rate and sampling principles in their inductive inferences. Third, we ask how these early inductive abilities can be harnessed for improving later mathematics education and inductive inference. We make several suggestions for future empirical work that should go a long way in addressing the many remaining open questions in this growing research area.
Collapse
Affiliation(s)
| | - Fei Xu
- 2 Department of Psychology, University of California, Berkeley
| |
Collapse
|
13
|
Abstract
Humans can use an intuitive sense of statistics to make predictions about uncertain future events, a cognitive skill that underpins logical and mathematical reasoning. Recent research shows that some of these abilities for statistical inferences can emerge in preverbal infants and non-human primates such as apes and capuchins. An important question is therefore whether animals share the full complement of intuitive reasoning abilities demonstrated by humans, as well as what evolutionary contexts promote the emergence of such skills. Here, we examined whether free-ranging rhesus macaques (Macaca mulatta) can use probability information to infer the most likely outcome of a random lottery, in the first test of whether primates can make such inferences in the absence of direct prior experience. We developed a novel expectancy-violation looking time task, adapted from prior studies of infants, in order to assess the monkeys' expectations. In Study 1, we confirmed that monkeys (n = 20) looked similarly at different sampled items if they had no prior knowledge about the population they were drawn from. In Study 2, monkeys (n = 80) saw a dynamic 'lottery' machine containing a mix of two types of fruit outcomes, and then saw either the more common fruit (expected trial) or the relatively rare fruit (unexpected trial) fall from the machine. We found that monkeys looked longer when they witnessed the unexpected outcome. In Study 3, we confirmed that this effect depended on the causal relationship between the sample and the population, not visual mismatch: monkeys (n = 80) looked equally at both outcomes if the experimenter pulled the sampled item from her pocket. These results reveal that rhesus monkeys spontaneously use information about probability to reason about likely outcomes, and show how comparative studies of nonhumans can disentangle the evolutionary history of logical reasoning capacities.
Collapse
Affiliation(s)
- Francesca De Petrillo
- Department of Psychology, University of Michigan, 530 Church St, Ann Arbor, MI 48109 USA.,Institute for Advance Study in Toulouse, Manufacture des Tabacs, 21, Allée de Brienne, 31015 Toulouse, France
| | - Alexandra G Rosati
- Department of Psychology, University of Michigan, 530 Church St, Ann Arbor, MI 48109 USA.,Department of Anthropology, University of Michigan
| |
Collapse
|
14
|
|
15
|
Eckert J, Call J, Hermes J, Herrmann E, Rakoczy H. Intuitive statistical inferences in chimpanzees and humans follow Weber's law. Cognition 2018; 180:99-107. [PMID: 30015211 DOI: 10.1016/j.cognition.2018.07.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 06/12/2018] [Accepted: 07/04/2018] [Indexed: 02/07/2023]
Abstract
Humans and nonhuman great apes share a sense for intuitive statistical reasoning, making intuitive probability judgments based on proportional information. This ability is of fundamental importance, in particular for inferring general regularities from finite numbers of observations and, vice versa, for predicting the outcome of single events using prior information. To date it remains unclear which cognitive mechanism underlies and enables this capacity. The aim of the present study was to gain deeper insights into the cognitive structure of intuitive statistics by probing its signatures in chimpanzees and humans. We tested 24 sanctuary-living chimpanzees in a previously established paradigm which required them to reason from populations of food items with different ratios of preferred (peanuts) and non-preferred items (carrot pieces) to randomly drawn samples. In a series of eight test conditions, the ratio between the two ratios to be discriminated (ROR) was systematically varied ranging from 1 (same proportions in both populations) to 16 (high magnitude of difference between populations). One hundred and forty-four human adults were tested in a computerized version of the same task. The main result was that both chimpanzee and human performance varied as a function of the log(ROR) and thus followed Weber's law. This suggests that intuitive statistical reasoning relies on the same cognitive mechanism that is used for comparing absolute quantities, namely the analogue magnitude system.
Collapse
Affiliation(s)
- Johanna Eckert
- Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany; Department of Developmental Psychology, University of Goettingen, Waldweg 26, 37073 Goettingen, Germany; Leibniz ScienceCampus "Primate Cognition", German Primate Center/Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Goettingen, Germany.
| | - Josep Call
- Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany; School of Psychology and Neuroscience, University of St Andrews, St Andrews KY16 9JP, UK
| | - Jonas Hermes
- Department of Developmental Psychology, University of Goettingen, Waldweg 26, 37073 Goettingen, Germany; Leibniz ScienceCampus "Primate Cognition", German Primate Center/Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Goettingen, Germany
| | - Esther Herrmann
- Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Hannes Rakoczy
- Department of Developmental Psychology, University of Goettingen, Waldweg 26, 37073 Goettingen, Germany; Leibniz ScienceCampus "Primate Cognition", German Primate Center/Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Goettingen, Germany
| |
Collapse
|
16
|
Chimpanzees prioritise social information over pre-existing behaviours in a group context but not in dyads. Anim Cogn 2018; 21:407-418. [PMID: 29574554 PMCID: PMC5908815 DOI: 10.1007/s10071-018-1178-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 03/05/2018] [Accepted: 03/16/2018] [Indexed: 11/23/2022]
Abstract
How animal communities arrive at homogeneous behavioural preferences is a central question for studies of cultural evolution. Here, we investigated whether chimpanzees (Pan troglodytes) would relinquish a pre-existing behaviour to adopt an alternative demonstrated by an overwhelming majority of group mates; in other words, whether chimpanzees behave in a conformist manner. In each of five groups of chimpanzees (N = 37), one individual was trained on one method of opening a two-action puzzle box to obtain food, while the remaining individuals learned the alternative method. Over 5 h of open access to the apparatus in a group context, it was found that 4/5 ‘minority’ individuals explored the majority method and three of these used this new method in the majority of trials. Those that switched did so after observing only a small subset of their group, thereby not matching conventional definitions of conformity. In a further ‘Dyad’ condition, six pairs of chimpanzees were trained on alternative methods and then given access to the task together. Only one of these individuals ever switched method. The number of observations that individuals in the minority and Dyad individuals made of their untrained method was not found to influence whether or not they themselves switched to use it. In a final ‘Asocial’ condition, individuals (N = 10) did not receive social information and did not deviate from their first-learned method. We argue that these results demonstrate an important influence of social context upon prioritisation of social information over pre-existing methods, which can result in group homogeneity of behaviour.
Collapse
|