Mind and behavior
In previous chapters, we have entertained extensive discussions of the mental realm and its interactions with physical objects, albeit in an implicitly human context. We will not re-hash the various arguments here.
We remind the reader of our Russellian-monist flavor of panpsychism:
we accept the existence of quiddities in the form of instrinc properties of physico-mental objects, carrying phenomenal value as qualia or proto-qualia.
intentional states are conceived as physico-mental emergents on top of these latent quiddities and specific physical structures (as a vaguely defined idea, strictly to pain a picture: neural network-like meshes).
Then we note that these sharp philosophical choices are perfectly compatible with a naive, folk approach that we shall adopt (lest this historical/scientific panorama devolves into a full-fledged study of psychology):
non-animal organisms may display traits we could associate with mental or behavioral features, but don’t have minds as commonly understood.
animals with nervous systems do things; the sum of what they do makes up behavior.
animals with nervous systems believe, feel, want things; these mental states together coalesce into a macroscopic mind, which is not qualitatively different from the human mind, despite enormous quantitative differences in complexity.
Animal behavior
What is behavior?
At its root, behavior is part of an animal’s phenotype, its observable characteristics.
The term has a clear intuitive meaning: we know that the shape of a dog’s skull is part of it phenotype, but not an example of behavior, while the fact that a dog chases squirrels is part of its behavior. Most dictionary definitions seem content to stay circular, asserting behavior covers anything an animal does or any way that it acts, which is just moving the lexicographic goalposts.
More discriminating criteria are used at times, but should be handled prudently. References to movement are sometimes floated, but the freezing of a deer in headlights is just as much behavior as the flight of a fox in the same headlights. Behavior is occasionally tied to the nervous and/or endocrine systems, but these systems also govern involuntary functions like digestion or heartbeats that can hardly be considered actions. A definition could also rely on external or internal stimuli as the drivers for behavior, but those are equally hard to delineate.
Another criterion tells us that to behave is to do something voluntarily, to show an individual will. That is more philosophical in nature, and indeed is at the core of how we have defined action, in a human context, as "the difference between the fact that my arm is moving, and the fact that I raised my arm". But I had already accepted the existence of mental states, giving ontological shelter to the concept of action.
I can easily extend that approach to animals, but that choice is not ontologically neutral. To pure behaviorists (mental skeptics), mental states, such as they are, are a fairly restricted set, one type of behavior among others, or perhaps simple determinants of behavior. Conversely, my own approach would tend to ground behavior and action in the concept of mind, giving it clearer boundaries, at the cost (to the parsimonious) of accepting the mental realm.
For practical purposes, in ethology and animal psychology, the definition is not that corseted and a "know it when you see it" folk approach is preferrable.
Types of behavior
The reflex arc is the simplest unit of behavior: a well-defined stimulus activates a sensory neuron, which conveys the signal to a motor neuron, which triggers a muscular response. Reflexes are fast, automatic, and stereotyped (literal knee-jerk responses), and often essential for survival... but they are inflexible: t he same stimulus always elicits the same response.
Innate patterns bring the first layer of flexibility. They are more complex sequences of behavior, but still genetically determined and very stereotyped. A spider building its web, a bird performing its courtship display, follow their species’ perennial sequence, triggered by a specific stimulus. Innate patterns can be extremely elaborate, but they are rigid: the pattern will be completed after initiation, regardless of environmental changes.
Learned behavior is the next layer: the permanent modification of activity as a result of experience. We can roughly order its forms by complexity:
Non-associative learning:
Habituation: the waning of a response to a repeated, inconsequential stimulus.
Sensitization: conversely, a heightened response to stimuli following a noxious or startling event.
Associative learning: linking a stimulus or action to a consequence.
Classical conditioning: a neutral stimulus is paired with a significant one (food), until the neutral stimulus alone triggers a response.
Operant conditioning: an animal’s own actions appear determined by their outcomes (risk/reward).
Higher-order learning:
Observational learning: acquiring a behavior by watching another individual perform it.
Spatial learning: building and updating a cognitive map of the environment.
Insight learning: solving a novel problem without trial-and-error, through apparent mental manipulation of representations.
The capacity for learning is itself a product of evolution, shaped by the ecological demands on each species. Animals that face predictable, stable environments tend to rely more on innate behavior; those that face variable, complex environments tend to invest more in learning.
The innate/learned distinction is of course far from clear-cut. Animals go through maturation, a series of developmental windows where a genetic blueprint enables pre-disposed forms of learning in the presence of the right environmental stimuli. One classic example is bird singing: without any exposure to others’ songs, a young bird can never acquire that skill; the learning pattern that takes song models as inputs manifests only within a species-specific age range.
Conative States
The mentalist view of behavior involves the existence of a first class of mental states called conative states.
More colloquially, these correspond to desires, wishes, aims, urges, and any other form of volition. They may constitute the aspect of the mind that reaches most beyond nervous systems into the very origins of life. The basic biochemical machinery of a bacteria already equips the organism with a set of processes it is hard for us to not over-interpret as teleological and goal-oriented: moving towards food, avoiding danger, seeking heat or light...
On a continuous spectrum, complex organisms’ conative states resemble less and less the simplistic responses of their predecessors to environmental stimuli, and more and more into manifestation of a persistent will with a distinct orientation towards a goal.
Affective states
The word "emotion" is loaded with human connotations, more neutrally we can talk of affective states: mental states that are (at minimum) positively or negatively valenced, influence decision-making, and have characteristic physiological and behavioral signatures.
Any nomenclature in this domain is arbitrary but I will mention Panksepp, who identified universal "systems" with convincing neural correlates in many animals:
lust: a state that mediates sexual attraction and the urge to reproduce.
care drives the urge to protect and nurture (e.g. offspring).
excitement: an appetitive state that motivates foraging, exploration, and curiosity.
anger, triggered by frustration or restraint, provides the energy for self-defence and asserting boundaries.
grief is activated by the loss of social contact or a caregiver.
fear: an aversion to pain or danger.
These basic systems are similar to the top-level categories from the many attempts by psychologists at classifying the much richer space of human emotions.:
Love: lust, affection, longing...
Joy: delight, thrill, pleasure, pride, hope, relief...
Anger: annoyance, frustration, rage, disgust, envy, torment...
Sadness: displeasure, sorrow, agony, shame, pity, loneliness...
Fear: anxiety, dread, alarm, fright...
As could be said of all mental states, emotions can hardly be considered as discrete entities in isolation from each other and distinct mental processes. That is especially true when considering their evolutionary emergence. Many of the more complex emotions like shame, pride, hope, require capacity for self-consciousness, representation building or social norm awareness, which effectively restricts them, as far as we know, to great apes (at the most).
Moods, defined as diffuse, extended affective states, are plausible in animals. A dog that is persistently sluggish and withdrawn after the death of a companion can be said to be in a depressed mood, linked to a durable physiological imbalance between the basic affective systems.
Sentiments, stable affective orientations toward specific individuals, are evident in any species with individual recognition, like primates, elephants, canids, corvids, cetaceans, and likely many others.
The combination and dynamics of longer-term tendencies like moods and sentiments contribute to the emergence of temperament, individuality, personality, culminating with humans in full-blown personhood.
Cognitive States
Cognition is the last part of a triad that reflects an age-old philosophical view of mind. Kant, in his most famous works distinguished judgment, practical reason and pure reason. This in turn harks back to the ancient trio of supreme values: affects find their perfect accomplishment in Beauty, aims and desires in Good, and cognitive attitudes in Truth.
In folk psychological terms, cognition encompasses a motley crue of mental states, processes and capacities connected in some way to belief, knowledge or reasons. Again, let’s remind ourselves that these themes have been abundantly discussed in previous chapters from the perspective of philosophical underpinnings, which we will not revisit here. Let us quickly mention a few of the revelant terms instead:
beliefs, or judgements, are persistent states that associate some representations (mental content) with doxastic valence.
perceptions are not the raw sensory stimuli (which do not belong to the mental) but their cognitively-mediated representation.
thinking and reasoning are purely internal processes (untethered from perceptions) that generate new belief states.
attention designates the ability to focus, i.e. to stage a representational foreground for a selection of propositional attitudes or processes.
imagination is a family of capacities that enable the mind to examine representations without direct sensory input.
Needless to say, this is not a rigorous taxonomy, since these concepts are both qualitatively different and overlapping or redundant to various extents.
In line with the discussion of self-consciousness in previous chapters, we may add that metacognition allows to perform cognitive tasks on the representations of one’s own mental states.
The question of non-human cognition is very much unsettled and a topic of active research. Neuroscience associates advanced cognitive states with executive functions performed mostly by the neocortex area, a part of the brain only found in mammals. Besides humans, the species with notable neocortical prominence are great apes, cetaceans (dolphins, whales...), elephants, followed at a healthy distance by cats, monkeys and small mammals like mice.
Memory
The existence of memory seems to be directly implied by what precedes: without even evoking mental states, if behavior can be modified by learning in a persistent manner without changes to the permanent architecture of the nervous system (like reflexes), there must be something to retain the acquired information.
Short-term and working memory
Short-term, or working memory holds information for seconds to minutes, in the form of sustained neural activity neurons that keep firing, maintaining a transient representation. For instance, it would allow a predator to remember the trajectory of a prey while it takes a detour or avoids an obstacle.
Long-term memory
Long-term memory stores information for hours, days, or a lifetime. Truth be told, the underlying physical or biological mechanisms are poorly understood at the time of writing. One candidiate is the process of long-term potentiation (LTP): when two neurons fire together repeatedly, the synapse between them is strengthened, which leads to the the insertion of additional receptor proteins into the postsynaptic membrane and to the growth of new synaptic connections.
Long-term memory can be further subdivided (keeping in mind the breakdown is largely conceptual: we can observe that different parts of the brain are stimulated in each case, but not prove a sharp difference in the biological basis) :
Procedural memory (motor skills, learned sequences): stored in the cerebellum and basal ganglia.
Declarative memory (knowledge of facts and events): depends on the hippocampus and associated cortical areas.
Semantic memory: general conceptual knowledge about the world.
Episodic memory: memory of specific past events.