PhD student in Biological Anthropology, specializing in the behavior and evolution of monkeys.
How smart are animals, really? Do we even have the scientific tools to address the question?
People always want to know which animals are the smartest - are dogs smarter than cats? Are dolphins smarter than humans?
The problem with these questions is that we don't have a good scientific definition for what 'intelligence' actually means. Even within a single species, Homo sapiens, scientists have been unable to come up with a reliable measure of intelligence, forcing us to rely on shaky measures like the notoriously unreliable IQ test. If we can't come up with a reliable measure of intelligence in humans alone, how can we come up with one that works across different species?
There's a famous story that illustrates how difficult it is to study animal intelligence. Back in the 1980s, some researchers discovered a correlation between IQ and 'inspection time,' or the length of time you can look at an image and process the information it contains (for example, you get a short glimpse of two lines and have to respond with which one is longer). Inspection time was briefly touted as a measure of intelligence that could be used on both humans and animals - until we learned that chimpanzees are vastly better at it than humans! That meant if we wanted to keep using inspection time as a measure we'd have to accept that chimps are smarter than humans. Nobody wanted to admit that.
No one doubts that there's something unusual about human cognition. We just have a really hard time identifying what that 'something' is, and figuring out ways to measure it in other animals.
Clearly, the human gift has something to do with language. We all learned at least one language effortlessly when we were kids, yet other animals are only able to learn very basic symbol systems - and even then it takes years of training and doesn't always work. So if the idea of 'animal intelligence' is going to get anywhere in the scientific world, we're going to have to figure out what the cognitive skills are that enable us to learn language so easily while other animals struggle with it.
Abstract: The ability to learn is common to most animal species: the need to exploit past experience being obviously extremely important for survival, many animals have evolved ways of coping with it. Although the complexity of learning needed for optimal survival may be different in different species, the basic mechanisms appear to be fairly constant even in phylogenetically distant ones. This homogeneity across species in learning mechanisms is in some ways surprising in view of the large phylogenetic differences and of the considerable variability not only in the general plan of their bodily structures, but also, more specifically, in their neural organization and in their behavioral adaptations. One possible explanation is that animals have acquired learning very precociously, and that the original and basic mechanisms have proved so efficient and faultproof as to be preserved from then on without any significant modification. Most researchers of the subject seem to accept the equation «intelligence=learning capability», operationally very useful because it leads to a variety of formal tests. Some researchers, stressing that behavior is subject to the same evolutionary principles as any other character of the organism and acknowledging some problems in the accepted laws of learning, have tried to find a satisfactory answer to the question of animal intelligence by attempting a synthesis between the concepts of animal learning psychology and those of ethology. To some extent, dissatisfaction with established learning theories originated within the theories themselves: the study of phenomena such as autoshaping, selective attention, preferential learning of some responses amongst the many possible, conditioned learning of taste aversions, etc. Further difficulties for conditioning theories arose from the discovery of ethological phenomena. Other researchers have attempted to check the hypothesis that animals possess cognition. A number of complex experimental situtations have been devised to this purpose, but the results still are far from conclusive.
Pub.: 01 Dec '88, Pinned: 09 May '17
Abstract: In "The Snark is a Boojum", Beach [Beach, F.A., 1950. The snark was a boojum. American Psychologist. 5, 115-124] famously asserted that animal psychology embraced too few species and too few problems to deserve the name comparative. Later in the 20th century, others [e.g. Kamil, A.C., 1988. A synthetic approach to the study of animal intelligence. In: Leger, D.W. (Ed.), Comparative Perspectives in Modern Psychology. Nebraska Symposium on Motivation, vol. 35. University of Nebraska Press, Lincoln, NE, pp. 230-257; Shettleworth, S.J., 1993. Where is the comparison in comparative cognition? Alternative research programs. Psychological Science. 4, 179-184] expressed similar concerns about the new subfield of comparative cognition, suggesting that a more biological approach to choice of species and problems was needed to balance a dominant anthropocentrism. The last 10-15 years have seen many new developments, and a recent survey like Beach's reveals a very different picture. Not only are many more species being studied, contributions by researchers from different backgrounds are increasing, and research on comparative cognition is better connected with developmental psychology, behavioral neuroscience, primatology, behavioral ecology, and other fields. Contemporary research addresses three major aspects of cognition about equally: basic processes, physical cognition, and social cognition. This article describes a selected research program from each area, chosen to exemplify current trends and challenges for the field.
Pub.: 01 Oct '08, Pinned: 09 May '17
Abstract: Accumulating evidence indicates that the storage and processing capabilities of the human working memory system co-vary with individuals' performance on a wide range of cognitive tasks. The ubiquitous nature of this relationship suggests that variations in these processes may underlie individual differences in intelligence. Here we briefly review relevant data which supports this view. Furthermore, we emphasize an emerging literature describing a trait in genetically heterogeneous mice that is quantitatively and qualitatively analogous to general intelligence (g) in humans. As in humans, this animal analog of g co-varies with individual differences in both storage and processing components of the working memory system. Absent some of the complications associated with work with human subjects (e.g., phonological processing), this work with laboratory animals has provided an opportunity to assess otherwise intractable hypotheses. For instance, it has been possible in animals to manipulate individual aspects of the working memory system (e.g., selective attention), and to observe causal relationships between these variables and the expression of general cognitive abilities. This work with laboratory animals has coincided with human imaging studies (briefly reviewed here) which suggest that common brain structures (e.g., prefrontal cortex) mediate the efficacy of selective attention and the performance of individuals on intelligence test batteries. In total, this evidence suggests an evolutionary conservation of the processes that co-vary with and/or regulate "intelligence" and provides a framework for promoting these abilities in both young and old animals.
Pub.: 18 Jul '09, Pinned: 09 May '17
Abstract: During the second half of the nineteenth century, the advent of widespread pet ownership was accompanied by claims of heightened animal abilities. Psychical researchers investigated many of these claims, including animal telepathy and ghostly apparitions. By the beginning of the twentieth century, news of horses and dogs with the ability to read and calculate fascinated the French public and scientists alike. Amidst questions about the justification of animal cruelty in laboratory experiments, wonder animals came to represent some extraordinary possibilities associated with their kind. Psychologists speculated on the feats of wonder animals. They considered the possibility that these animals shared consciousness and intelligence with humans, and that-if confirmed-their alleged amazing abilities could lead to a new understanding of cognition for all animals. This article focuses on the few years during which claims of wonder animals occupied a significant place in French psychology and psychical research. It argues that as explanations involving deception or unconscious cues gained increased acceptance, the interest in wonder animals soon led to a backlash in comparative psychology that had repercussions for all animals, particularly those used in experimentation, in that it contributed to the decline of research addressing cognitive abilities in non-human species.
Pub.: 27 Feb '10, Pinned: 09 May '17
Abstract: Many attempts have been made to correlate degrees of both animal and human intelligence with brain properties. With respect to mammals, a much-discussed trait concerns absolute and relative brain size, either uncorrected or corrected for body size. However, the correlation of both with degrees of intelligence yields large inconsistencies, because although they are regarded as the most intelligent mammals, monkeys and apes, including humans, have neither the absolutely nor the relatively largest brains. The best fit between brain traits and degrees of intelligence among mammals is reached by a combination of the number of cortical neurons, neuron packing density, interneuronal distance and axonal conduction velocity--factors that determine general information processing capacity (IPC), as reflected by general intelligence. The highest IPC is found in humans, followed by the great apes, Old World and New World monkeys. The IPC of cetaceans and elephants is much lower because of a thin cortex, low neuron packing density and low axonal conduction velocity. By contrast, corvid and psittacid birds have very small and densely packed pallial neurons and relatively many neurons, which, despite very small brain volumes, might explain their high intelligence. The evolution of a syntactical and grammatical language in humans most probably has served as an additional intelligence amplifier, which may have happened in songbirds and psittacids in a convergent manner.
Pub.: 26 Nov '15, Pinned: 09 May '17
Abstract: Conwy Lloyd Morgan (1852–1936) is widely regarded as the father of modern comparative psychology. Yet, Morgan initially had significant doubts about whether a genuine science of comparative psychology was even possible, only later becoming more optimistic about our ability to make reliable inferences about the mental capacities of non-human animals. There has been a fair amount of disagreement amongst scholars of Morgan’s work about the nature, timing, and causes of this shift in Morgan’s thinking. We argue that Morgan underwent two quite different shifts of attitude towards the proper practice of comparative psychology. The first was a qualified acceptance of the Romanesian approach to comparative psychology that he had initially criticized. The second was a shift away from Romanes’ reliance on systematizing anecdotal evidence of animal intelligence towards an experimental approach, focused on studying the development of behaviour. We emphasize the role of Morgan’s evolving epistemological views in bringing about the first shift – in particular, his philosophy of science. We emphasize the role of an intriguing but overlooked figure in the history of comparative psychology in explaining the second shift, T. Mann Jones, whose correspondence with Morgan provided an important catalyst for Morgan’s experimental turn, particularly the special focus on development. We also shed light on the intended function of Morgan’s Canon, the methodological principle for which Morgan is now mostly known. The Canon can only be properly understood by seeing it in the context of Morgan’s own unique experimental vision for comparative psychology.
Pub.: 25 Jul '16, Pinned: 09 May '17
Abstract: Conformity to local behavioral norms reflects the pervading role of culture in human life. Laboratory experiments have begun to suggest a role for conformity in animal social learning, but evidence from the wild remains circumstantial. Here, we show experimentally that wild vervet monkeys will abandon personal foraging preferences in favor of group norms new to them. Groups first learned to avoid the bitter-tasting alternative of two foods. Presentations of these options untreated months later revealed that all new infants naïve to the foods adopted maternal preferences. Males who migrated between groups where the alternative food was eaten switched to the new local norm. Such powerful effects of social learning represent a more potent force than hitherto recognized in shaping group differences among wild animals.
Pub.: 27 Apr '13, Pinned: 09 May '17
Abstract: Network optimality has been described in genes, proteins and human communicative networks. In the latter, optimality leads to the efficient transmission of information with a minimum number of connections. Whilst studies show that differences in centrality exist in animal networks with central individuals having higher fitness, network efficiency has never been studied in animal groups. Here we studied 78 groups of primates (24 species). We found that group size and neocortex ratio were correlated with network efficiency. Centralisation (whether several individuals are central in the group) and modularity (how a group is clustered) had opposing effects on network efficiency, showing that tolerant species have more efficient networks. Such network properties affecting individual fitness could be shaped by natural selection. Our results are in accordance with the social brain and cultural intelligence hypotheses, which suggest that the importance of network efficiency and information flow through social learning relates to cognitive abilities.
Pub.: 24 Dec '14, Pinned: 09 May '17
Abstract: Experimental studies of animal social learning in the wild remain rare, especially those that employ the most discriminating tests in which alternative means to complete naturalistic tasks are seeded in different groups. We applied this approach to wild vervet monkeys (Chlorocebus aethiops) using an artificial fruit ('vervetable') opened by either lifting a door panel or sliding it left or right. In one group, a trained model lifted the door, and in two others, the model slid it either left or right. Members of each group then watched their model before being given access to multiple baited vervetables with all opening techniques possible. Thirteen of these monkeys opened vervetables, displaying a significant tendency to use the seeded technique on their first opening and over the course of the experiment. The option preferred in these monkeys' first successful manipulation session was also highly correlated with the proportional frequency of the option they had previously witnessed. The social learning effects thus documented go beyond mere stimulus enhancement insofar as the same door knob was grasped for either technique. Results thus suggest that through imitation, emulation or both, new foraging techniques will spread across groups of wild vervet monkeys to create incipient foraging traditions.
Pub.: 30 Dec '14, Pinned: 09 May '17
Abstract: Some birds achieve primate-like levels of cognition, even though their brains tend to be much smaller in absolute size. This poses a fundamental problem in comparative and computational neuroscience, because small brains are expected to have a lower information-processing capacity. Using the isotropic fractionator to determine numbers of neurons in specific brain regions, here we show that the brains of parrots and songbirds contain on average twice as many neurons as primate brains of the same mass, indicating that avian brains have higher neuron packing densities than mammalian brains. Additionally, corvids and parrots have much higher proportions of brain neurons located in the pallial telencephalon compared with primates or other mammals and birds. Thus, large-brained parrots and corvids have forebrain neuron counts equal to or greater than primates with much larger brains. We suggest that the large numbers of neurons concentrated in high densities in the telencephalon substantially contribute to the neural basis of avian intelligence.
Pub.: 13 Jun '16, Pinned: 09 May '17
Abstract: Noting important recent discoveries, we review primate social learning, traditions and culture, together with associated findings about primate brains. We survey our current knowledge of primate cultures in the wild, and complementary experimental diffusion studies testing species' capacity to sustain traditions. We relate this work to theories that seek to explain the enlarged brain size of primates as specializations for social intelligence, that have most recently extended to learning from others and the cultural transmission this permits. We discuss alternative theories and review a variety of recent findings that support cultural intelligence hypotheses for primate encephalization. At a more fine-grained neuroscientific level we focus on the underlying processes of social learning, especially emulation and imitation. Here, our own and others' recent research has established capacities for bodily imitation in both monkeys and apes, results that are consistent with a role for the mirror neuron system in social learning. We review important convergences between behavioural findings and recent non-invasive neuroscientific studies.
Pub.: 31 Dec '16, Pinned: 09 May '17