Research Interests
My research examines conceptual and methodological problems in comparative (animal) cognition science and their implications for the treatment of nonhuman animals.
In one project (“simplicity in comparative cognition”) I argue that a preference for simpler explanations can bias scientific methodology, yielding not only a less reliable science of animal cognition, but a science that is less likely to identify morally relevant cognitive properties in animals. A second, and related, project (“minds without spines”) aims to develop an empirically grounded ethics for invertebrates as different as cephalopod mollusks, insects, and arachnids – a broad class of animals that are currently either neglected or lumped together in traditional animal ethics. Such an account is especially pressing in light of the near total absence of legal and institutional protections for invertebrates in research, even as we discover remarkably sophisticated behavior (and possibly cognition) in such animals as octopuses, jumping spiders, bumblebees, and more. A third project (“evolved cognition”) takes an evolutionary and ecological approach to an understanding of mind; while a fourth project (“experimentation”) offers an account of experimentation across diverse scientific disciplines.
In addition to these core topics, I have abiding research interests in biomedical ethics and moral and political philosophy.
In one project (“simplicity in comparative cognition”) I argue that a preference for simpler explanations can bias scientific methodology, yielding not only a less reliable science of animal cognition, but a science that is less likely to identify morally relevant cognitive properties in animals. A second, and related, project (“minds without spines”) aims to develop an empirically grounded ethics for invertebrates as different as cephalopod mollusks, insects, and arachnids – a broad class of animals that are currently either neglected or lumped together in traditional animal ethics. Such an account is especially pressing in light of the near total absence of legal and institutional protections for invertebrates in research, even as we discover remarkably sophisticated behavior (and possibly cognition) in such animals as octopuses, jumping spiders, bumblebees, and more. A third project (“evolved cognition”) takes an evolutionary and ecological approach to an understanding of mind; while a fourth project (“experimentation”) offers an account of experimentation across diverse scientific disciplines.
In addition to these core topics, I have abiding research interests in biomedical ethics and moral and political philosophy.
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EVOLVED COGNITION
This project centers on questions about the convergent evolution of cognitive functions – focusing in particular on finding a principled answer to the question of what permits similarity judgments about cognitive unobservables across morphologically diverse taxa. I begin by considering a central unanswered question in comparative cognition: what justifies the common inference that flexible behaviors are evidence of cognitive complexity? In one of my current papers (co-authored with Corina Logan and Russell Powell), we offer an evolutionary model as justification for this central inference. Future research on this subject will consider the implications of evidence from arthropod (including insect and arachnid) brains for the relationship between brain size and cognitive sophistication. Evidence from tiny-brained but behaviorally sophisticated animals such as jumping spiders, I argue, upsets traditional views of cognition and the cognitive and neural architecture instantiating animal thinking. |
MINDS WITHOUT SPINES: TOWARD A MORE COMPREHENSIVE ANIMAL ETHICS
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Project Summary
Over the last two decades a growing body of research in comparative cognition has demonstrated sophisticated abilities such as concept formation, problem solving, spatial reasoning, and emotional response in invertebrate animals whose brains had previously been thought to be too small or else too alien to house even simple cognition. The behavioral evidence is further bolstered by emerging findings in neuroethology and computational modeling, which reveal not only that these animals have complex centralized brains, but that far more computational power may be packed into these tiny brains than had previously been thought. Although these findings may have significant implications for the moral standing of a number of invertebrate groups—including not only cephalopod mollusks but also arthropods such as insects and arachnids—they have not made their way into mainstream (or even peripheral) ethical thought. To the extent that ‘invertebrates’ are discussed in the animal ethics literature or in public policy, they are typically lumped into a single undifferentiated category despite the remarkable phenotypic and phylogenetic diversity of animals the term describes. The entire category—which accounts for approximately 95% of all extant species and an astounding 99.9% of all animals on Earth—is then excluded from subject-centered moral consideration and, consequently, experimental welfare protections, with one recent exception made for octopuses.
Complicating matters further, there are significant conceptual and methodological problems in animal cognition science, both in general and in relation to the study of invertebrate cognition and brains in particular, that result in significant uncertainties about the presence of complex cognitive mechanisms in the animals studied—and it is unclear how these scientific uncertainties should affect our ethical analyses. One such challenge concerns the matter of how to draw reliable similarity judgments about cognitive function across structurally and functionally different neural platforms (e.g., the cortical regions of mammalian brains and the mushroom bodies of insects) in the general absence of clear homology. To the extent that the behavioral and neurobiological evidence may be subject to multiple interpretations, which in turn ground different claims regarding moral status, a further conceptual challenge for scientists and ethicists alike concerns how to interpret this data in a manner befitting the dual pursuits of scientific accuracy and ethical caution. Finally, invertebrate cognition challenges the traditional account of moral standing itself. The standard account of moral standing assumes a strong conceptual link between interests and the subjective experience of pain. Invertebrate cognition raises the possibility that beings may have moral standing without the ability to experience pain in ways that are phenomenologically similar to the manner in which we and many other vertebrates experience it.
The time is ripe, therefore, to develop a more comprehensive, inclusive, and scientifically engaged animal ethics—one that brings novel scientific findings to bear on ethical thought and public policy while addressing the conceptual challenges inherent in the study of these alien minds. I begin this project by identifying a range of cognitive and methodological biases and unwarranted theoretical assumptions that impede progress in animal cognition research generally and invertebrate cognition research in particular. I then survey preliminary behavioral and neurobiological evidence of sophisticated cognition and conscious awareness in invertebrates and the implications of these findings for the nature and evolution of mind. Next, I turn my attention to the conceptual and inferential challenges that confront the scientific investigation of invertebrate minds and brains. I then consider the demands that these challenges place on ethical analysis, drawing tentative conclusions about the moral standing of invertebrates. The project culminates with the suggestion that invertebrate cognition and phenomenology may not merely call for an expansion of the moral circle to include some invertebrate animals, but may in fact present a challenge for traditional accounts of moral standing that presuppose vertebrate-like pain phenomenologies.
Project Plan
This project consists of four parts. In Part I, I will evaluate the cognitive biases and theoretical assumptions behind the neglect of invertebrates in serious explorations of animal welfare. Cognitive biases include (inter alia) the empathy gap toward animals with unexpressive or ‘unattractive’ faces, such as fishes, insects, and spiders, and size threshold biases that afford greater moral consideration to larger animals (such as lobsters over honeybees). One may argue that the size bias is ultimately rational because the tiny brains of many invertebrates cannot in principle support sentience or cognition. However, comparative neuroscience strongly suggests that the information-processing capability of brains is a function not of absolute size, but such things as neuronal density, modularity, connectivity, and metabolic activity. Crucially, these do not linearly scale with size, suggesting that even tiny brains may possess the raw materials for their own form of thought and feeling – properties that may confer moral standing. Such comparative neuroscientific and cognitive evidence is explored in detail in Part II, in which I review the preliminary evidence of cognitive sophistication. My focus here will be cutting-edge work that is currently being done on historically neglected taxa, particularly arthropods such as bees and spiders. For example, among the insects, honeybees appear to be capable of multi-modal and cross-modal learning, paper wasps recognize conspecifics as individuals rather than merely by caste, and bumblebees engage in social learning and appear to experience emotions. Cephalopod mollusks, such as octopus and cuttlefish, have excellent spatial navigation abilities, and octopuses excel at problem-solving and have been observed using tools. Among arachnids, the tiny jumping spider can rapidly and flexibly switch among many hunting strategies, from stalking its prey (e.g., another spider) by crouching behind a leaf, to attempting to trick it by mimicking the web vibrations made by its prey, to executing a long detour to an ambush location just above its prey – an act that requires sophisticated spatial memory.
However, a reliable evidence base requires reliable inferential strategies and drawing reliable inferences about invertebrate cognition is especially challenging given their “alien” morphology, neuroanatomy, and lifeways. Although this challenge is not unique to invertebrate cognition research, it is more vivid given the radical differences between vertebrates—with whom we share a great deal of structural and developmental homology—and mollusks and arthropods who boast nervous systems that evolved completely independently in animal lineages that diverged from vertebrates nearly one billion years ago. Thus, Part III addresses methodological and conceptual problems in developing an inclusive and scientifically engaged animal ethics. In addition to the inferential challenges specific to invertebrate cognition research, this section addresses challenges within animal cognition research more broadly. For example, cognitive hypotheses are often underdetermined by behavioral evidence – a problem to which comparative cognition science has responded by adopting a de facto policy of favoring the simplest hypothesis consistent with the behavioral evidence. This “simplicity preference,” however, requires justification, which is unlikely to be forthcoming for several reasons. Most basically, there is no such thing as simplicity simpliciter, but, rather, numerous mutually irreducible means of simplification. Thus, any broad-based preference for simplicity is likely to be too coarse-grained to be of scientific use. Further, the operative assumption that biological outcomes (including behavior) will tend to have simple rather than complex causes seems particularly ill-suited for the biological world, in which functional complexity is the norm and simplicity the exception at all levels of the biological hierarchy. One conceptual challenge for an inclusive animal ethics thus lies in identifying empirically and evolutionarily sound solutions to the underdetermination problem.
Another challenge concerns the competing error-avoidance strategies employed by comparative cognition science on the one hand and by ethical approaches to nonhuman animals on the other. While animal cognition science errs on the side of avoiding false positives (e.g., ascribing sophisticated cognition to animals when they do not in fact possess these abilities), animal ethics has reason to err on the side of avoiding false negatives (e.g., failing to identify a morally relevant cognitive property in nonhuman animals or margin-zone humans when they in fact possess them). Thus, the burden of proof for the presence of a morally relevant property such as pain perception or planning abilities will tend to be significantly higher for the scientist than for the ethicist. This burden of proof gap requires a means by which ethicists may reconcile scientists’ skepticism with their own precautionary approach, and that would allow them to challenge scientific error-avoidance strategies whenever these lack epistemic warrant – a challenge that requires the input of philosophy of science. I conclude this section by drawing out the implications of the foregoing discussion for laws and public policies governing the treatment of invertebrates both within and beyond the experimental context.
Finally, in Part IV, I examine how evidence from invertebrate cognition may put pressure on traditional conceptions of moral standing, which have been keyed in to the relationship between interests and the subjective experience of pain. A full accounting of the evidence may suggest that some invertebrates have the cognitive capacities that give rise to full-blown interests and yet lack the ability to experience pain in ways that are familiar to humans and other vertebrates. If this is indeed the case, then the cognitive and phenomenological worlds of invertebrate animals present a challenge for traditional accounts of moral standing, which did not anticipate that psychological interests and the subjective experience of pain may come apart.
Over the last two decades a growing body of research in comparative cognition has demonstrated sophisticated abilities such as concept formation, problem solving, spatial reasoning, and emotional response in invertebrate animals whose brains had previously been thought to be too small or else too alien to house even simple cognition. The behavioral evidence is further bolstered by emerging findings in neuroethology and computational modeling, which reveal not only that these animals have complex centralized brains, but that far more computational power may be packed into these tiny brains than had previously been thought. Although these findings may have significant implications for the moral standing of a number of invertebrate groups—including not only cephalopod mollusks but also arthropods such as insects and arachnids—they have not made their way into mainstream (or even peripheral) ethical thought. To the extent that ‘invertebrates’ are discussed in the animal ethics literature or in public policy, they are typically lumped into a single undifferentiated category despite the remarkable phenotypic and phylogenetic diversity of animals the term describes. The entire category—which accounts for approximately 95% of all extant species and an astounding 99.9% of all animals on Earth—is then excluded from subject-centered moral consideration and, consequently, experimental welfare protections, with one recent exception made for octopuses.
Complicating matters further, there are significant conceptual and methodological problems in animal cognition science, both in general and in relation to the study of invertebrate cognition and brains in particular, that result in significant uncertainties about the presence of complex cognitive mechanisms in the animals studied—and it is unclear how these scientific uncertainties should affect our ethical analyses. One such challenge concerns the matter of how to draw reliable similarity judgments about cognitive function across structurally and functionally different neural platforms (e.g., the cortical regions of mammalian brains and the mushroom bodies of insects) in the general absence of clear homology. To the extent that the behavioral and neurobiological evidence may be subject to multiple interpretations, which in turn ground different claims regarding moral status, a further conceptual challenge for scientists and ethicists alike concerns how to interpret this data in a manner befitting the dual pursuits of scientific accuracy and ethical caution. Finally, invertebrate cognition challenges the traditional account of moral standing itself. The standard account of moral standing assumes a strong conceptual link between interests and the subjective experience of pain. Invertebrate cognition raises the possibility that beings may have moral standing without the ability to experience pain in ways that are phenomenologically similar to the manner in which we and many other vertebrates experience it.
The time is ripe, therefore, to develop a more comprehensive, inclusive, and scientifically engaged animal ethics—one that brings novel scientific findings to bear on ethical thought and public policy while addressing the conceptual challenges inherent in the study of these alien minds. I begin this project by identifying a range of cognitive and methodological biases and unwarranted theoretical assumptions that impede progress in animal cognition research generally and invertebrate cognition research in particular. I then survey preliminary behavioral and neurobiological evidence of sophisticated cognition and conscious awareness in invertebrates and the implications of these findings for the nature and evolution of mind. Next, I turn my attention to the conceptual and inferential challenges that confront the scientific investigation of invertebrate minds and brains. I then consider the demands that these challenges place on ethical analysis, drawing tentative conclusions about the moral standing of invertebrates. The project culminates with the suggestion that invertebrate cognition and phenomenology may not merely call for an expansion of the moral circle to include some invertebrate animals, but may in fact present a challenge for traditional accounts of moral standing that presuppose vertebrate-like pain phenomenologies.
Project Plan
This project consists of four parts. In Part I, I will evaluate the cognitive biases and theoretical assumptions behind the neglect of invertebrates in serious explorations of animal welfare. Cognitive biases include (inter alia) the empathy gap toward animals with unexpressive or ‘unattractive’ faces, such as fishes, insects, and spiders, and size threshold biases that afford greater moral consideration to larger animals (such as lobsters over honeybees). One may argue that the size bias is ultimately rational because the tiny brains of many invertebrates cannot in principle support sentience or cognition. However, comparative neuroscience strongly suggests that the information-processing capability of brains is a function not of absolute size, but such things as neuronal density, modularity, connectivity, and metabolic activity. Crucially, these do not linearly scale with size, suggesting that even tiny brains may possess the raw materials for their own form of thought and feeling – properties that may confer moral standing. Such comparative neuroscientific and cognitive evidence is explored in detail in Part II, in which I review the preliminary evidence of cognitive sophistication. My focus here will be cutting-edge work that is currently being done on historically neglected taxa, particularly arthropods such as bees and spiders. For example, among the insects, honeybees appear to be capable of multi-modal and cross-modal learning, paper wasps recognize conspecifics as individuals rather than merely by caste, and bumblebees engage in social learning and appear to experience emotions. Cephalopod mollusks, such as octopus and cuttlefish, have excellent spatial navigation abilities, and octopuses excel at problem-solving and have been observed using tools. Among arachnids, the tiny jumping spider can rapidly and flexibly switch among many hunting strategies, from stalking its prey (e.g., another spider) by crouching behind a leaf, to attempting to trick it by mimicking the web vibrations made by its prey, to executing a long detour to an ambush location just above its prey – an act that requires sophisticated spatial memory.
However, a reliable evidence base requires reliable inferential strategies and drawing reliable inferences about invertebrate cognition is especially challenging given their “alien” morphology, neuroanatomy, and lifeways. Although this challenge is not unique to invertebrate cognition research, it is more vivid given the radical differences between vertebrates—with whom we share a great deal of structural and developmental homology—and mollusks and arthropods who boast nervous systems that evolved completely independently in animal lineages that diverged from vertebrates nearly one billion years ago. Thus, Part III addresses methodological and conceptual problems in developing an inclusive and scientifically engaged animal ethics. In addition to the inferential challenges specific to invertebrate cognition research, this section addresses challenges within animal cognition research more broadly. For example, cognitive hypotheses are often underdetermined by behavioral evidence – a problem to which comparative cognition science has responded by adopting a de facto policy of favoring the simplest hypothesis consistent with the behavioral evidence. This “simplicity preference,” however, requires justification, which is unlikely to be forthcoming for several reasons. Most basically, there is no such thing as simplicity simpliciter, but, rather, numerous mutually irreducible means of simplification. Thus, any broad-based preference for simplicity is likely to be too coarse-grained to be of scientific use. Further, the operative assumption that biological outcomes (including behavior) will tend to have simple rather than complex causes seems particularly ill-suited for the biological world, in which functional complexity is the norm and simplicity the exception at all levels of the biological hierarchy. One conceptual challenge for an inclusive animal ethics thus lies in identifying empirically and evolutionarily sound solutions to the underdetermination problem.
Another challenge concerns the competing error-avoidance strategies employed by comparative cognition science on the one hand and by ethical approaches to nonhuman animals on the other. While animal cognition science errs on the side of avoiding false positives (e.g., ascribing sophisticated cognition to animals when they do not in fact possess these abilities), animal ethics has reason to err on the side of avoiding false negatives (e.g., failing to identify a morally relevant cognitive property in nonhuman animals or margin-zone humans when they in fact possess them). Thus, the burden of proof for the presence of a morally relevant property such as pain perception or planning abilities will tend to be significantly higher for the scientist than for the ethicist. This burden of proof gap requires a means by which ethicists may reconcile scientists’ skepticism with their own precautionary approach, and that would allow them to challenge scientific error-avoidance strategies whenever these lack epistemic warrant – a challenge that requires the input of philosophy of science. I conclude this section by drawing out the implications of the foregoing discussion for laws and public policies governing the treatment of invertebrates both within and beyond the experimental context.
Finally, in Part IV, I examine how evidence from invertebrate cognition may put pressure on traditional conceptions of moral standing, which have been keyed in to the relationship between interests and the subjective experience of pain. A full accounting of the evidence may suggest that some invertebrates have the cognitive capacities that give rise to full-blown interests and yet lack the ability to experience pain in ways that are familiar to humans and other vertebrates. If this is indeed the case, then the cognitive and phenomenological worlds of invertebrate animals present a challenge for traditional accounts of moral standing, which did not anticipate that psychological interests and the subjective experience of pain may come apart.