Is consciousness a by-product of natural selection?

[otseng]

I would like to pick up on a statement that ST88 made.

Consciousness is just a by-product of natural selection.

So, for debate:
What is consciousness?
How did the consciousness arise by natural selection?

[juliod]

What is consciousness?

The ability to directly respond to stimuli.

This is as opposed to the inability to respond (e.g. rocks) and the ability to respond only indirectly (e.g. most plants).

Phototactic bacteria are "aware", in the most crude way, of the presence or absence of light. Similar to this is the ability of some plants to move in relation to light.

Indirect responses (which don't count) include such things as the differential growth of plants with respect to light. A stalk that is exposed to light grows more than one in perpetual shade. It's not a stimulus-response, but a conseqeunce of the fact that plants need light to fix carbon.

Above this simple level are increasing grades of complexity, but in my view, no sharp cut-off. From protozoans, to simple multi-cellular animals, though mollusks and insects, up to the more advanced animals. Primates seem to be on the top of the scale, but I wouldn't be suprised if there were some metric by which predatory cats could be seen as more conscious than we apes.

How did the consciousness arise by natural selection?

I don't see why this would be an issue. The ability to respond to the environment is an obvious selective advantage. And since there is a gradient of abilities from the simplest chemo- or photo-tactic responses through to our "advanced" abilities there doesn't seem to be any problem. There's no gaps, no missing links, and there are as many intermediate forms as you would care to examine.

DanZ

[CJO]

"What is consciousness?"
I would like to delineate "consciousness" from "sentience" and claim that, in fact, humans are the only animal species to demonstrate the former. In this view, all of juliod's "intermediate forms" are greater or lesser degrees of sentience, which even the simplest creatures have to some small degree.

But the big question is "How did consciousness arise by natural selection?"

Rather than diving right in with consciousness, which is somewhat nebulous and ill-defined, let's start with some gross anatomical features unique to the human animal: upright posture, articulated hands with a fully opposable thumb, large cranial capacity and overdeveloped neo-cortex, highly complex facial musculature, and a vocal tract allowing for highly modulated sound production. I believe that the evolution of these features tells the story of the evolution of consciousness.

Many theorists have seen links between the first two features, believing either that selection pressure for upright posture and bipedal locomotion "freed up" the hands, or that selection pressure for "handiness" led to upright stature. Either way, paleoanthropology has made clear that tool manufacture has been an element of life for hominids for at least several million years. This, in and of itself, implies cooperation, foresight, and the transmission of expertise, in short, the beginnings of culture. The data from paleontology also clearly shows a steady increase in our hominid ancestors' cranial capacity, facilitating, it is believed, a steady increase in the size and complexity of the cerebral cortex. The consequences of this, "the great encephalization," cannot be overestimated. The selection pressure for cranial capacity, always balanced against the size of the birth canal, engendered a feedback loop whereby increasing neoteny of offspring required greater parental investment in the rearing of young, requiring a yet greater degree of social organization, requiring higher intelligence, feeding back into the relentless pressure for more room in the skull. This is the "bootstrapping phase" of the evolution of consciousness.
What happens next happened very fast by the timeframe of evolution. The increased premium on cooperation and organization removed our ancestors, to some degree, from the ordinary pressures of animal ecology. In short, the most important feature of early humans' environment became other humans; we became our own niche. The more this became true, the greater selection pressure became for communicative ability, and, especially, the ability to parse others' communication, not just for simple intercourse, but for the purposes of "cheating detection." Basically, in such a milieu, the best manipulators began to take advantage of their neighbors, garnering a disproportionate share of the social group's resources and, crucially for natural selection, to have more and healthier offspring. In order to not get taken for a ride, everybody needed to be alert for "unfair" advantages gained by their neighbors. The broad range of human emotion, with its attendent suite of distinctive facial expressions can be seen as a heritage of the early stages of this process. At some point, of course, speech arose, and became the primary carrier of human communication. The organic, evolved nature of the human capacity for language is hard to deny: several anatomical features of the left hemisphere of the neo-cortex are dedicated to speech and speech comprehension.
So, once our ancestors' communicative capacities are fully on-line, the evolution of consciousness can be approaced directly. Basically, the complexity of production and reception of language requires from the cortex dedicated serial processing. The necessity of monitoring others' internal states to detect deception and untoward advantage-taking, led to constant internal modeling of the social environment, which, I believe, led to self-consciousness, as the best way to "know" what others were thinking was to know what you, yourself, were thinking. The many other advantages of consciousness, such as forethought and deliberation, only served to reinforce its adaptiveness.

So, there's a sketch of how I think it happened, informed by many sources, of course. I hope it will inspire some debate, and provide an opportunity for me to clarify my thoughts on the matter through discussion.

[Lotan]

The necessity of monitoring others' internal states to detect deception and untoward advantage-taking, led to constant internal modeling of the social environment, which, I believe, led to self-consciousness, as the best way to "know" what others were thinking was to know what you, yourself, were thinking.

If this is the requirement for consciousness then modern chimpanzees qualify as 'conscious' too, having demonstrated exactly this type of behaviour.

[CJO]

The necessity of monitoring others' internal states to detect deception and untoward advantage-taking, led to constant internal modeling of the social environment, which, I believe, led to self-consciousness, as the best way to "know" what others were thinking was to know what you, yourself, were thinking.

If this is the requirement for consciousness then modern chimpanzees qualify as 'conscious' too, having demonstrated exactly this type of behaviour.

I said "the necessity" led to... "modeling", which led to "self-consciousness"

So, no, I'm not saying that it's sufficient for self-consciousness, I'm saying that it created the selection pressure that led to consciousness as an adaptation. Cimpanzees have maybe set one foot on a road that has taken us a hundred miles. I submit that there's no reason to believe they'll go much further.

Also, I'd like to see some examples of what you believe to be the demonstration of self-consciousness by chimpanzees, so we know what we're talking about. I mean, clearly, the animal kingdom provides other examples of this kind of social behavior. Surely within a pack of wolves, with its hierarchy, there's awareness on the part of individuals of their place in the pecking order and their relationship with other wolves. Is that self-consciousness?

[otseng]

I think we should first try to come to a general consensus as to what we mean by "consciousness" before going into too much detail on the origin of it. Otherwise, I can see the debate going around in circles with people using differing definitions of consciousness.

Now, coming up with a generally acceptable definition might be impossible. It probably is impossible since not even the professionals (doctors, philosophers, psychologists, etc) can come up with a good definition. But, I think it might prove interesting to just try to agree on a definition of it.

OK, here's a start from some sources:

Dictionary.com:

1. The state or condition of being conscious.
2. A sense of one's personal or collective identity, including the attitudes, beliefs, and sensitivities held by or considered characteristic of an individual or group: Love of freedom runs deep in the national consciousness.
3.
a. Special awareness or sensitivity: class consciousness; race consciousness.
b. Alertness to or concern for a particular issue or situation: a movement aimed at raising the general public's consciousness of social injustice.
4. In psychoanalysis, the conscious.

M-W:

1 a : the quality or state of being aware especially of something within oneself b : the state or fact of being conscious of an external object, state, or fact c : AWARENESS; especially : concern for some social or political cause
2 : the state of being characterized by sensation, emotion, volition, and thought : MIND
3 : the totality of conscious states of an individual
4 : the normal state of conscious life <regained consciousness>
5 : the upper level of mental life of which the person is aware as contrasted with unconscious processes

Infoplease:

1. the state of being conscious; awareness of one's own existence, sensations, thoughts, surroundings, etc.
2. the thoughts and feelings, collectively, of an individual or of an aggregate of people: the moral consciousness of a nation.
3. full activity of the mind and senses, as in waking life: to regain consciousness after fainting.
4. awareness of something for what it is; internal knowledge: consciousness of wrongdoing.
5. concern, interest, or acute awareness: class consciousness.
6. the mental activity of which a person is aware as contrasted with unconscious mental processes.
7. Philos.the mind or the mental faculties as characterized by thought, feelings, and volition.
8. raise one's consciousness, to increase one's awareness and understanding of one's own needs, behavior, attitudes, etc., esp. as a member of a particular social or political group.

Encarta:

1. being awake and aware of surroundings: the state of being awake and aware of what is going on around you
feelings of dizziness followed by loss of consciousness
2. somebody’s mind: somebody’s mind and thoughts
In time, this experience will fade from your consciousness.
3. shared feelings and beliefs: the set of opinions, feelings, and beliefs of a group
4. being aware of specific issues: awareness of or sensitivity to issues in a particular field
5. awareness of thoughts and feelings: the part of the human mind that is aware of the feelings, thoughts, and surroundings

[CJO]

Since the most applicable of these definitions refer to "thought" I thought I'd bring up some definitions of "thought" and "think" as well.

From Dictionary.com:

To have or formulate in the mind.

To reason about or reflect on; ponder: Think how complex language is. Think the matter through.
To decide by reasoning, reflection, or pondering: thinking what to do.
To judge or regard; look upon: I think it only fair.
To believe; suppose: always thought he was right.

To call to mind; remember: I can't think what her name was.
To visualize; imagine: Think what a scene it will be at the reunion.
To devise or evolve; invent: thought up a plan to get rich quick.
To bring into a given condition by mental preoccupation: He thought himself into a panic over the impending examination.
To concentrate one's thoughts on: &#8220;Think languor&#8221; (Diana Vreeland).

To exercise the power of reason, as by conceiving ideas, drawing inferences, and using judgment.
To weigh or consider an idea: They are thinking about moving.

To bring a thought to mind by imagination or invention

The bold text indicates what, to me, is the crucial element of consciousness: the ability to reason and reflect, especially upon subjects that are not close at hand, and to imagine that which does not even exist outside of thought. It is this ability that I believe humans are unique in possessing. At the very least, I think, our capacity for this kind of thought is so much more developed than that of our closest cousins as to be a difference truly of kind, not just one of degree. Put perhaps too simply, I believe there to be a "cognitive threshold" that humans long ago passed in their evolution, which no other animal even approaches. Note that I am not maintaining that other animals have no interior lives at all, or that they don't "think" in some sense. I'm saying that this in and of itself does not equate to true "consciousness."

[LillSnopp]

The bold text indicates what, to me, is the crucial element of consciousness: the ability to reason and reflect, especially upon subjects that are not close at hand, and to imagine that which does not even exist outside of thought. It is this ability that I believe humans are unique in possessing.

That would be cognitive thinking (Thought).
But sure, lets go with that:

This would mean that most animals have consciousness, as, lets take a squirrel, would collect nuts for the winter, this is a clear sign of thinking ahead. A squirrel would also defend itself from preys, as it does not want to die, a clear sign of knowing whats ahead (death). And so forth.

Agreed?

[CJO]

The bold text indicates what, to me, is the crucial element of consciousness: the ability to reason and reflect, especially upon subjects that are not close at hand, and to imagine that which does not even exist outside of thought. It is this ability that I believe humans are unique in possessing.

That would be cognitive thinking (Thought).
But sure, lets go with that:

This would mean that most animals have consciousness, as, lets take a squirrel, would collect nuts for the winter, this is a clear sign of thinking ahead. A squirrel would also defend itself from preys, as it does not want to die, a clear sign of knowing whats ahead (death). And so forth.

Agreed?

Emphatically not agreed.
Squirrels collecting food, birds building nests or migrating, and a host of seemingly "intelligent" animal behaviors are a clear example of adaptive behaviors driven by "hard-wired" instincts, not remotely close to the human ability to project into the future and plan accordingly.

Good research on all htese fronts, and many, many more has been done by animal behaviorists.

As far as avoiding death, by your argument, bacteria are conscious, since they move toward food and away from harmful substances.

"Stimulus, response, stimulus, response... Don't you ever THINK?"
(Gary Larson joke)

[juliod]

Put perhaps too simply, I believe there to be a "cognitive threshold" that humans long ago passed in their evolution, which no other animal even approaches.

I don't agree. I don't think we'll reach a consensus for this thread in any case.

In my post I mentioned predatory cats. It's not clear to me that we can claim they are "less cognative" than we are. Stalking, hiding, approach-by-stealth, etc, are all indicative of extreme congnition. And with their hightened senses, I suspect that they bring "awareness" to a level where they regard us as those slow, dull ape-creatures who need a whole group to hunt a dead hyena (but gee aren't there a lot of them around these days...).

DanZ