By: David Nortman
Introduction
In an 1896 paper entitled "A New Factor in Evolution" American psychologist and social theorist James Mark Baldwin (1861-1934) advanced an idea he called "organic selection." This idea concerned the evolution of organisms through the acquisition of new skills or abilities during their lifetime. This problem had preoccupied evolutionary bio-logists in the late nineteenth century because, although Darwin's evolutionary theory had been able to account for the evolution of fixed traits (such as the size of a certain species' canine teeth) by the mechanism of natural selection, it fell short of explaining the evolution of traits that were not fixed, but learned during the organism's life. These traits (such as the ability to communicate verbally) seemed better explained by an older hypothesis proposed by Jean-Baptiste Lamarck (1744-1829) back in 1809, according to which organisms preserved and further developed those traits which they used during their lifetime, subsequently transmitting the modifications to their off-spring. But no mechanism was ever found to substantiate Lamarck's view; at best it provided a description of the common observation that certain behavioural traits were transmitted with slight modification from parents to offspring, most evidently in the case of highly social and intelligent animals. This 'cultural' sort of evolution did not require a physical mechanism, and was seen to act inde-pendently of physical evolution. The latter was considered more fundamental, and insofar as culturally evolved traits affected survival they did so indirectly, through their effect on physical survival.
Faced with this split account of the evolution of social animals including humans, Baldwin sought to provide a Darwinian account of adaptation that would explain in biological rather than sociological terms the evolution of those acquired traits that were characterized by (i) complexity and (ii) incapacity for being genetically transmitted to subsequent generations. Abilities requiring the overt use of intelligence fell into this category: for example, Baldwin sought to explain the evolution of the ability to develop various sorts of fine motor skills in response to demands encountered through life. If, say, a cave man learned to throw a sharpened branch at an animal in response to the need for food, the motor skills involved in that action would not be preserved in his genes, because genes could not preserve such specific things as the 'instructions' for throwing a javelin-like object.1 But for Darwin the preferential survival of those organisms that possessed certain fitness-enhancing traits was always determined by their genetic inheritance rather than by acquisition of skill through life, regardless of the amount of effort directed toward such learning. Thus Darwin's theory in its pure form accounted only for the effect of phylogenetic rather than ontogenic2 adaptation on evolution.3 For the first time Baldwin incorporated ontogenic adaptation or intelligent "accommodation" into a Darwinian (i.e. non-Lamarckian) paradigm through his idea of "organic selection" (Baldwin 1896) in order to factor in the effect of skill acquisition on physical evolution. This became an intermediate sort of evolution (between physical and social), and was later named 'Baldwin Effect'.4
Following is an outline of organic selection as described by Baldwin himself in his 1896 paper and then in terms of the modern notions of phenotyic plasticity and cerebral plasticity; a discussion of the general constraints on cerebral evolution; the implications of the Baldwin Effect on the train of evolution; and some philosophical implications on our understanding of the mind and human nature.
Organic selection
Baldwin's (1896) presentation of organic selection is very detailed, and so we can but summarise the main features that are most pertinent to our discussion. Baldwin considers natural selection a negative factor in evolution, because it merely determines which organisms will not survive, without addressing the question of what means successful organisms must employ through their life in order to survive. He observes that "[o]rganisms that did not have some form of selective response to what was beneficial, as opposed to what was damaging in the environment, could not have developed very far" (550). Organic selection, on the other hand, is a positive factor that describes what individual organisms undergo in their struggle to survive, concerning itself with "what they can do, rather than...what they are" (551, italics in original). Now, what organisms tend to do in life is to seek pleasure and shrink from pain. Natural selection contends that by properly avoiding unfavourable stimuli organisms will survive to the best of their genetic endowment; but they can do no better than this. Organic selection suggests that, by a process of learning guided by both reward and punishment, an organism is able to experiment with potential adaptations, determine those that are beneficial for survival then and there, and tend later to pursue them over less beneficial ones, thus augmenting its long-term survival.
But "how does the organism secure, from the multitude of possible ontogenic changes which it might and does undergo, those which are adaptive?" (542). This is best done if there is initially an overproduction of behaviour, such that an initial state of random overactivity gets refined through experience to produce a useful adaptation. This pattern of overproduction followed by pruning is universally observed in the brains of infants (which lose many of their neurons in the first months of life) as well as in their lively but uncoordinated movement. It also parallels natural selection, which likewise operates on the basis of over-production of individuals some of which get 'pruned' in every generation; if everyone were to survive (i.e., if there were no overproduction of characteristics) then natural selection would cease to be a factor in evolution. Conversely, whenever there is overproduction of behaviour, organic selection becomes a factor. The initial over-production is due to hereditary influence, but the pruning and refinement in behaviour is ontogenic. Depending on the nature of the refined behaviour, certain aspects of the hereditary potential (which manifests as overproduction) will be reinforced in subsequent generations; specifically, if intelligence, memory, and other cognitive attributes are operative in the stage of refinement then they will be reinforced whenever such refinement leads to the survival of the whole organism. And because greater cognitive capacity is highly, if not universally, advantageous, later on we will speak of cognitive capacity almost synonymously with cerebral plasticity, and correlate both of these closely with the organism's overall fitness.
Thus Baldwin's central conclusion is that both phylogenetic and ontogenic mechanisms of adaptation are necessary in order to account for the evolution of all but the most rudimentary of animals. Moreover, "these two lines of hereditary influence are not separate nor uninfluential on each other" (541); in other words, in addition to the recognised effect of heredity on life experience, the latter just as surely reflects back on heredity. As we can see, ultimately it is most accurate to speak of the unit of selection of the individual not as physical, nor as secondarily psychophysical, but as fundamentally psychophysical: it is not that by virtue of the mind the successful physical creature's physical characteristics are transmitted, but rather that by virtue of the organism's favourable psychophysical makeup that its psychophysical character-istics are transmitted.
Features of the Baldwin Effect
When we just spoke of "organic selection" we referred to a Darwinian rather than Lamarckian mechanism of evolution of acquired skills. In a more modern context, the Baldwin Effect is a mechanism that can be said to explain the evolution of phenotypic plasticity, which is the organism's flexibility and creativity in adapting its behaviour to the environment as demands arise, often unexpectedly, throughout its life. Given that genotype (one's genetic code) is fixed at the time of conception, plasticity of phenotype (phenotype being the actualisation of genetic potential through interaction with the environment-the individual organism taken as such) also represents a broad measure of an individual organism's fitness (a measure of the organism's success in reproduction). This is because plasticity arising from high cognitive capacity is universally advantageous, tending to contribute to any organism's fit-ness regardless of the specific circumstances of its life. Here the heritability of actual learning experiences within organi-sms' lives is measured: though learning usually occurs within a cultural context (broadly speaking), the ability to learn is obviously prior to learning and therefore innate. Its biological innateness in turn makes the ability to learn measurable in terms of fitness, which is a biological construct. Thus the ability to learn is not itself a culturally evolved trait.
When earlier we noted that the instructions for acquired skills (such as javelin throwing) were not held in the genetic code we did not account for how else learning was preserved. Turning now to this issue, we can state uncontroversially that the memory of learned skills is found in the higher centres of the brain. Most notable is the rapid increase in the size of the cerebral cortex in recent evolutionary history. The cerebral cortex houses abilities that are unique to the most intelligent of the higher mammals, and in some cases unique to humans alone. Just as Mendel's genetic discoveries around the turn of the twentieth century buttressed Darwin's theory by providing a physical substrate and mechanism for the transmission of genetic characteristics, likewise the science of neurology is now advanced enough to be able to supply a physical mechanism for the evolution of the brain. But the dizzying pace of the growth of the cerebral cortex is still baffling because of remaining gaps in the understanding of its recent evolution. This state of affairs could be improved if the Baldwin Effect were brought into consideration. Accordingly, the rest of this paper will discuss the Baldwin Effect in terms of its contribution to the evolution of cerebral plasticity, meaning the ability of the organism's brain to modify its structure (insofar as structure determines function) throughout life so as to increase the organism's odds of survival.
Hard-wiring versus plasticity
"We all assume that the future will be like the past" (Dennett 1991, 182). Well, perhaps we humans have come to recognise that that is not always so. Still, the statement is strictly true for non-intelligent systems-be they individ-ual organisms, ecological systems, or evolutionary proces-ses of other scales-since those cannot ever contemplate their future. But the ecological niches which organisms inhabit are never utterly unpredictable in every respect, so a modicum of continuity usually exists. This allows creatures lacking foresight to evolve and thrive.
The most efficient manner of 'constructing' organisms for survival within a predictable environment is through hard-wiring both structure and behaviour. Hard-wired features have the key advantage that they are immediately available to the organism, without needing to be learned. Microorganisms, for example, possess only pre-wired traits, and accordingly they come into existence as fully functional beings; all adaptations they exhibit are coded genetically.5 At the other extreme, humans require many years of care before they can be considered mature and functional adults, as many survival-related abilities must be learned in order to thrive in complex human environments. Hard-wiring clearly confers a survival advan-tage early in life, but because such traits are not amenable to alteration later on, any unforeseen change in the environment will strain the limited ontogenic adaptive capacity of predominantly hard-wired organisms. And be-cause any novelty in the environment is an unforeseen change to an unintelligent creature, it follows that hard-wiring is highly disadvantageous whenever environmental variability exists. In contrast, phenotypic plasticity affords the organism the ability to adapt to its environment, typically through the use of intelligence. We have here in essence the hard-wiring of plasticity: the guarantee through genetic coding that the organism will possess an enormous potential to make it through life by learning to adapt to ever-shifting circumstances. Those that survive to repro-duce will transmit this capability to their offspring. Since such adaptation is ubiquitous among the higher animals and humans, it is wise to enquire at the mechanisms responsible for this phenomenon.
General parameters of cerebral evolution
The brain is a remarkable expression of evolutionary laws. It is all the more remarkable once we note the following strict parameters that have determined its evolution to the present. First, for a brain to be useful for the survival of the organism it needs to react to external stimuli differentially by evaluating stimuli for their relevance and effect on survival. But the brain as physical structure has no access to the meaning contained in stimuli: "[T]he brain is 'blind' to the external conditions producing its input and must have some other way of discriminating by significance" (Dennett 1969, 48). Although "natural selection can provide for the dullest sort of appropriate reflex responses to stimuli discriminated by their meagre, in fact binary, 'significance'" (50), it cannot endow stimuli with meaning. But if we suppose an over-wired brain like that of newborn infants, then a primitive sort of value system is inherent in the pre-wired connections: "[A]ny of the initially haphazard connections that inadvertently competed with pre-wired connections would be inhibited...while any compatible hap-hazard connections would be allowed to complete them-selves, and...tend to recur" (58). Thus in the first years of human life many connections that have not been used become obsolete and atrophy (51-52). Hard-wired traits responsible for basic survival are exercised regularly and so remain in place, whereas plastic traits remain only if their potential is tapped by continued usage early in life, and it is these that potentially lead to novel behaviours or acts of cognition (58).
Another parameter, or rather the freedom from a constraint, is that cerebral functions do not need to be expressed through behaviour in order to be useful. What counts is the potential of employing some latent capacity for one's benefit. So long as a neural pathway is not detri-mental to survival, its potential future utility alone makes it valuable (Dennett 1969, 62-63).6 This is helpful, for example, when accounting for the evolution of highly com-plex traits. For our purposes let us regard a complex trait as one that requires the simultaneous presence of several simple traits which in isolation are insufficient for conferring a survival advantage. The likelihood of the complex trait's appearing would increase dramatically if the organism were able to hold on to a simple trait despite the lack of im-mediate survival advantage, just in case it proved useful in some future context. This continuum is provided by the ability to learn, remember, and recollect past experiences-all features of advanced cognitive capacity.
The 'adaptive landscape'
Imagine a varied landscape of hills, valleys, forests, plains, and so on. Now imagine yourself lost alone in this vast territory. With no map to guide you, your survival depends on your ability to obtain water, food, and shelter. One approach is to modify the landscape in your favour by digging a well, cultivating your food, and building a shelter. Another is to explore the landscape in search of these three basic requirements. Clearly some locations will favour your survival, whereas others will not, or may even endanger it. Ultimately your survival will depend on a combination of your ability to manipulate your immediate environment and your ability to judge where to go in search of life's basic needs.
Let us construct a conceptually similar 'adaptive landscape' consisting of many dimensions, with some 'locations' more favourable (i.e. fitness-enhancing) than others for survival. To accentuate this, let us conceive of a harsh landscape where only very few locations are fitness-enhancing to an appreciable degree. Whereas travelling through this novel landscape might require considerable physical ability, manipulating the landscape in one's favour instead requires considerable intelligence. Thus what may be a harsh landscape to one organism might turn out to be quite favourable to another, as the adaptive landscape (and with it the range of adaptations available to the organism) is relative to the organism, and more specifically relative to the organism's level of intelligence (insofar as intelligent thoughts turn into action). For example, the landscape available to three organisms living concurrently in the same location and subsisting on identical food sources depends largely on their individual potential in exploiting their environment, rather than on their actual abilities as determined by their physical attributes. The first of the three may be 'blind' to the presence of food beyond a ledge on which it should climb in order to obtain it, perhaps because of the effort required to climb it, an effort that does not appear worthwhile in advance, given that the presence of the reward is not known until afterward. The second organism may or may not be fortunate enough to stumble randomly on this innovative and highly rewarding be-haviour. The third, most active and intelligent of the three is predisposed to exploring the environment creatively, as if with a sense of anticipation that such activity could reap some reward. Thus, obtaining the food beyond the ledge is for the first organism an impossibility, for the second one is a potential though rarely realized adaptation, but for the third and most curious one it is a highly accessible adaptive niche. The advantage of the third over the first two organisms-access to a novel food source removed from competition from the other two organisms-is further amplified in case the availability of the new niche leads to further discovery, such as another ledge to climb on and more food to be obtained.
The example above suggests that plasticity of any sort is favoured by Baldwinian selection, because one adaptation subsequently exposes the organism to an indefinitely large and varied array of new adaptive niches, expanding the range of environments and situations in which the organism is fit to survive.7
The phylogenetic consequences of the Baldwin Effect
As we have seen, ontogenic adaptations secured by organisms through cerebral evolution reflect back upon phylogenetic evolution, as they must if they are to be preserved beyond the organism's lifespan. Their effect on evolution is twofold, tending both to accelerate it and to give it directionality toward the development of ever more intelligent creatures. In other words, the ability to explore many potential modes of behaviour within one lifetime through the use of intelligence results in specific selective pressures.
Evolution is accelerated when individual organisms discover a fitness-enhancing trait. But the creative behaviour of exceptional organisms within a group will often contribute not only to individual welfare but also to the welfare of the whole group. Moreover, since the exceptional organisms are (by definition) more fit than average, they will contribute more than average to the genetic makeup of future generations. This amplifies positive selective pressure so that the whole group experiences swift evolution 'toward' that trait through the reinforcement and amplification of the slight genetic propensity which led its exceptional members to behave in novel ways in the first place; indeed, this genetic propensity is likely found not only in those members but in the group as a whole, insofar as there might well have been other members in the group that exhibited creative behaviours but were not so fortunate as to stumble on a fitness-enhancing adaptation. In other words, though only a few organisms were selected for, the action of individual organisms led incidentally to the selection of the whole group and to the reinforcement of its genetic advantage vis-à-vis other groups.
Insofar as the Baldwin Effect contributes to evolution, the latter is directed toward the emergence of ever more intelligent creatures. The arrival of a new behavioural trait ushers in new selective pressures: creative organisms will tend to alter their native environment, look beyond the immediately beneficial and explore new environ-ments for their potential utility, form new social structures, and so on. Because the mechanism of transmission is not Lamarckian, i.e. the specific content of the cerebral adap-tation is lost when the organism dies, it is not specific traits but the general propensity to act in a certain (namely, more creative or intelligent) way which is reinforced and transmitted to future generations.8 The propensity toward greater plasticity or creativity, in combination with environ-mental (physical, biological, social) triggers, will tend first to reproduce those adaptations which were required in the previous generation, then further to allow for accom-modation to novel environments. If a cerebral adaptation offers an enormous increase in the adaptive landscape of an organism or group then certain aspects of cerebral plasticity will be accentuated further yet.
The strategies by which organisms take advantage of the possibilities inherent in the adaptive landscape may be grouped into three archetypes: the swift, the persistent, and the sophisticated. When employing the swift strategy an organism acts randomly, but is quick to explore an adaptive niche, learn its potential, and proceed to exploit it or else remember it for future exploitation (which requires a crude capacity for recollection). It thus covers much ground relative to its age, however haphazardly, gaining the advantage of improving its odds of survival early in life. The persistent strategist has the advantage of eventually covering the widest range of environments. Thus it may come across a fitness-enhancing adaptation found only at the far reaches of the adaptive landscape of its species, and hence fair better than if it were to employ the swift stra-tegy. On the other hand, it may take too long to explore the far reaches of the adaptive landscape, and therefore fail to capitalize on its potential. The third strategist, unlike the previous two, is able to learn how to learn. By learning which tactics of exploration tend to pay off, this organism is able to refine its subsequent exploration so as to pursue discovery of new adaptive niches ever more intelligently and creatively, leading possibly to greater efficiency.9 Finally, as the complexity of the adaptive landscape grows, abilities that were at first optional for survival may now become necessary for it. This is because as new survival-enhancing niches become available, the complexity of the adaptive landscape increases exponentially, just as the capacity of modern society to structure its environment always seems to be outstripped by the new demands that arise in return: the overcoming of one challenge will tend to create multiple new challenges to be overcome, and so on.
Once any of the above strategies is employed, a fourth one will arise: the strategy of imitation. The imitator may be regarded as a primitive sophisticated strategist, one that follows the single strategy of imitating other organisms in its environment. The capacity to imitate is pre-wired in many organisms such as birds. Most such species cannot independently concoct strategies, yet are capable of fol-lowing a pre-existing one, exemplifying the pre-wiring of plasticity that is the crux of the Baldwin Effect. But is the strategy of imitation a successful one? Given that imitation requires advanced cognitive capacity, the presence of the ability will be found in the higher animals, which so happen to be ones that are brought up by their parents before having to face the world alone. Now, parents are relatively successful members of their species, having survived to maturity and proven that they are fertile. Therefore the strategy of imitation, which not incidentally is most widely observed in the young, is a wise one so long as it occurs primarily early in life under the consistently fitness-enhancing adaptive landscape largely determined for the offspring by its parents.10
Mind, language and beyond
Current philosophy of mind is dominated by 'emergent' theories which regard the mind as supervenient on (i.e. logically subsequent to) the brain. A common computer analogy equates the brain with hardware and the mind with software; hardware exists prior to software, which can be written for it based on its capabilities. But if we observe that hardware is often built with specific software in mind, and that computer hardware is useless in the absence of appropriate software, then we can see that the two together form the thing we recognize as a computer. Now, if the mind has in the past contributed to the evolution of the brain, rather than 'emerging' at some stage in the brain's evolution, then we ought to question those theories which relegate it to a passive or secondary role. Whatever initially the mind appears to be to the modern observer, a full consideration from a comprehensive evolutionary per-spective will reveal the fault in regarding it as logically subsequent to the brain. In other words, if the Baldwin Effect is a valid factor in evolution then what has been selected for throughout evolutionary history is the mind and not the brain. More generally, this realisation should make it clear that the almost-exclusive focus on physical adaptations that has characterized evolutionary biology this past century is due to a pre-existing bias to search for causes in the physical realm, rather than due to over-whelming evidence in favour of the physical. It may well be that as theories of human and higher-animal nature become increasingly psychophysical in their emphasis, evolution will come generally to be regarded as fundamentally a psycho-physical phenomenon.11
Let us now turn to the specific case of the evolution of language, arguably the most advanced function of the mind. This will not only illustrate the value of imitation but will also demonstrate how certain constraints peculiar to the evolution of linguistic capacity-constraints which make it unlikely for this capacity to have arisen via natural selection alone-are overcome once the Baldwin Effect is posited. Deacon (1997) has argued that language could only have evolved in tandem with the brain through the Baldwin Effect. He points out that the range of predispositions open to selection via such mechanisms is wide, since any sort of indirect contribution to the organism's welfare is cherished and preserved, so that acquired behaviours quickly-often within the organism's lifetime-change the environment so as to make it necessary rather than desirable to possess the adaptation. Specifically, an infinitesimal gain in language capacity might have made it highly disadvantageous not to possess it, leading, for example, to the differential selection of grunting over more taciturn proto-humans (Deacon 1997, 322-327). Emerging linguistic ability would then alter the adaptive landscape of subsequent generations in a per-petual cycle of mutual reinforcement between language use and cerebral capacity. Because ability for language is argu-ably the most plastic use of cerebral plasticity, its selective advantage is enormous and unprecedented, thereby making the anomalously rapid evolution of the human cerebral cortex more accountable to the known laws of biology.
Language is, finally, a beautiful demonstration of the coordination of individually insignificant traits (the pro-duction of basic sounds) to produce a tool of enormous power, even the power to make us rise above our biological origins. The beauty of evolution at large, of which the evolution of language is a part, is that simple chemical and genetic building blocks come together to form dizzyingly complex creatures. Thus we see that the Baldwin Effect may be key for expanding our understanding of how it is that we live our lives not merely as biological creatures but also as psychological, moral, and spiritual beings. In other words, the Baldwin Effect may help to explain how we are each at once a simple being and one of endless possibility.12
Works Cited:
Baldwin, J.M. (1896). "A New Factor in Evolution." American Naturalist 30: 441-451, 536-553.
Deacon, T.W. (1997). The Symbolic Species: The Co-Evolution of Language and the Brain. New York: W.W. Norton & Company.
Dennett, D.C. (1969). Content and Consciousness. London: Routledge & Kegan Paul.
Dennett, D.C. (1991). Consciousness Explained. Boston, Toronto and London: Little, Brown and Company.
Richards, R.J. (1987). Darwin and the Emergence of Evolutionary Theories of Mind and Behaviour. Chicago: University of Chicago Press.
Sewny, V.D. (1945). The Social Theory of James Mark Baldwin. New York: King's Crown Press.
Notes:
1. Moreover, if such skills were only available through genetic inheritance then we would have to accept Plato's theory of the recollection of knowledge. Otherwise we would not be able to explain the acquisition of entirely novel skills such the use of a computer mouse: this species of mouse evolved only recently, so the 'instructions' for using it are clearly not in our genes.
2. Phylogenetic adaptation: adaptation occurring across generations (e.g., the rise of antibiotic resistance due to a higher survival rate of resistant individual bacteria, the latter reproducing to create entire colonies of resistant bacteria). Contrasts with ontogenic adaptation, which refers to adaptation occurring within an organism's lifetime (e.g., learning a new language after moving to a new country). Under the Darwinian paradigm it is phylogenetic rather than ontogenic adaptation that is the driving force behind evolution; the reverse holds true under the Lamarckian paradigm.
3. For example, according to the Darwinian mechanism those animals that had more effective (usually bigger) canine teeth faired better and proved more successful than others in the race for survival. Over time natural selection, acting in tandem with genetic variation, (obtained randomly through mutation, ever-shifting ecological pressures, etc.) would lead to new adaptations. As these accumulated, and as different adap-tations were needed in the different ecological niches that subsequent generations colonized, eventually new life forms emerged to produce the bewildering variety of creatures that today comprise the earth's biosphere.
4. Baldwin had first used the term "organic selection" in the context of social evolution in his Mental Development in the Child and the Race, published a year prior to his 1896 paper (Richards 1987, 488). At the time he likely had not stumbled on the idea that behavioural adaptations reflected back onto phylogeny (as will be explained below), and consequently he still regarded the biological transmission of mental capacities as a subset of their transmission via social evolution. The term "organic selection" in its mature expression in (Baldwin 1896) had been in common use in the years prior, with its meaning usually corresponding to 'cultural evolution'. Rather than coin a new term, Baldwin chose to usurp the one already in use despite the confusion this might cause, in part due to his desire to establish priority of discovery over his close rivals C.L. Morgan and H.F. Osborn (Sewny 1945, 59). For a detailed discussion of the politics surrounding the discovery see (Richards 1987, 480-495). For a general account of Baldwin's social theory see (Sewny 1945).
5. Bacteria and viruses could be said to engage in 'learning' whenever they interchange or otherwise manipulate their genetic code, as routinely observed by microbiologists. However, their learning can be explained in Darwinian terms, since newly acquired 'abilities' are at all times under the command of whatever genes that are present at the time.
6. This view contrasts with that of the behaviourist school of psychology, according to which all learned behaviour is invariably expressed at some time in the organism's lifetime.
7. Although Baldwinian adaptation is not by definition restricted to cerebral evolution, cerebral plasticity is in a class of its own with respect to potential gains. After all, several extra neurons are far more valuable than, say, several extra liver cells, because a small increase in the liver's capacity is not nearly as advantageous as a similar increase in the brain's capacity. Regardless, as will become apparent later, the Baldwin Effect most properly pertains to the evolution of the mind rather than the brain, so the question of where precisely the mind is housed becomes secondary.
8. It is useful to note that, given the limited number of genes from which even the most sophisticated organisms are constructed, it would likely be physically impossible for a myriad potential behaviours to be genetically coded, even if an evolutionary mechanism that allowed for such coding to take place were to be discovered.
9. Indeed, it is only this third strategist that can properly be called a strategist, since the first two approaches rather resemble fixed, inherited predispositions than ontogenically plastic abilities.
10. See for example (Baldwin 1896, 537).
11. Baldwin was led to introduce a third, psychophysical rather mental or physical, unit of selection of the individual partly by his pre-existing philosophical outlook, which gave prominence to the mind within a monistic framework similar to Spinoza's (Richards 1987, 451). But his theories were quickly forgotten in the twentieth century, largely because they did not resonate with the emerging modern philosophical outlook (Richards 1987, 495-503).
12. I would like to thank Prof. Ronald de Sousa for acquainting me with the Baldwin Effect, and for his comments on an earlier version of this paper.
