Classic Paper: Downward Causation In Hierarchically Organized Biological Systems
E:CO Issue Vol. 15 No. 3 2013 pp. 139-151
Classical
Classic Paper Section
DOWNWARD CAUSATION IN
HIERARCHICALLY ORGANIZED
BIOLOGICAL SYSTEMS
Donald Campbell (with an introduction by Jeffrey Goldstein)
Campbell, D.T. (1974) “Downward causation in hierarchically organized biological
systems,” in F.J. Ayala and T. Dobzhansky (eds.), Studies in the philosophy of biology:
Reduction and related problems, ISBN 9780520026490, pp. 179-186. Reproduced by
kind permission.
EVOLUTIONARY EPISTEMOLOGY AND COMPLEX
SYSTEMS: AN INTRODUCTION TO DONALD CAMPBELL’S
APPROACH TO DOWNWARD CAUSATION
D
onald T. Campbell (1916-1996; see Wikipedia entry) was an eminent psychologist, indeed all around prominent social scientist, with a doctorate from Berkeley, and who had a long academic and professional career, teaching stints at
Lehigh, Syracuse, Northwestern, and other high level universities and institutions, as
well as and at one time President of the American Psychological Association. Transdisciplinary in his themes, goals, and a quite impressive knowledge base, Campbell’s
research focused on bringing the major constructs of Darwinian evolution with what
he held as their revolutionary implications into the study of cognition, the nature of
science and how it progresses, and cultural and social evolution, all three areas exhibited in what he was probably best known for, namely, helping to inaugurate what
came to be called “evolutionary epistemology”.
Evolutionary Epistemology
According to Nathalie Gontier (2006) evolutionary epistemology is derived from the
psychology and sociology of knowledge, the history and philosophy of science, cogni-
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tive science, and the basic tenets of Darwinian evolution. At the heart of these various
disciplines is the notion of “progressive adaptation” which Campbell explained according to what he termed “blind-variation-and-selective-retention” (bvsr), the two
basic ingredients in evolution. For Campbell, bvsr is how knowledge, the “epistemology” part of “evolutionary epistemology” of any sort is acquired. It is gained by way of
interaction between an organism’s cognitive faculties and the environments in which
these cognitive capabilities operate.
Campbell’s bsvr-grounded approach was based in part on Popper’s view that science advances through the generation of hypotheses which are then affirmed or falsified by methodologically sound observations of the natural world as well as experimentation. “Blind variation” is behind the emergence of new theories through proposing conjectures. Then, selection refutes and selectively eliminates those conjectures
that are empirically falsified. Campbell added that the same logic of blind variation
and selective elimination/retention underlies all knowledge processes, not only scientific ones, although Gontier emphasizes a main goal of Campbell’s evolutionary epistemology” was to develop a “science of science”.
The trial and error approach of bsvr in science mirrors a similar evolutionary activity in social and cultural evolution as well as in each individual’s cognitive appropriation of her or his environment. .It is worth nothing that Campbell was quite open to a
great variety of means by which cognition acquires knowledge, presaging in this way
later work on multiple intelligences.
He also allowed for short cuts to bvsr vicarious selection, not necessarily more accurate but more efficient (Campbell, 1959: 162). These shortcuts themselves evolved
through a process of blind-variation-and-selective-retention. And later stages partly determine earlier stages of knowledge processes which Campbell (1974) termed
downward causation.
To be sure, the Popperian basis of Campbell’s evolutionary epistemology, this Popper’s rhythm of conjecture then falsification within Campbell’s variation and selection,
has not gone unchallenged. From Quine’s theory holism, to Kuhn’s clash of scientific
“worlds”, through Feyerabend’s epistemological anarchism to Lakatos’s fallibility of
mathematics, Popper’s tenet has seemed way too simplistic and regular. Nevertheless,
in my opinion, Campbell’s openness to a great variety of cognitive possibilities leaves
his approach credible despite the problematics of his Popperian assumptions.
Furthermore, although Campbell strongly rejected any “Panglossian” spin on the
role of purpose during the course of evolution, e.g., the introjection of teleology to
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substitute for blind variation and selection, Campbell did believe there was a crucial
role of teleonomy or apparent purposefulness as an aid in comprehending the goaldirectedness of various patterns and functioning exhibited in organisms. Unlike teleology, for Campbell a teleonomic process can generate complex products without the
benefit of foresight Wikipedia, Teleonomy).
Because of its unusual mixture of rigor and openness to alternatives, Campbell’s
turn to evolution in order to explain many psychological, social, and cultural phenomena managed to avoid the annoying just-so stories and hand-waving found in so
many social or psychological appropriations of evolutionary theory and which makes
much of them seem suspect. Obviously, evolution must play a huge role but not in the
simplistic way socio-biologists or evolutionary psychologists entertain, e.g., the ridiculous thesis of Pinker about the advance of civilization away toward greater peace and
happiness. If ever there was a more glaring case of a biased and arbitrarily gathering
of data to support an evolutionary tenet, I certainly don’t know what it is.
Downward Causation
As the idea of emergence has gained increasing prominence in the study of complex systems, ideas closely associated with it, particularly that of downward causation,
have become subject to a great deal of inquiry, disputes, and debates. Simply put,
downward causation (also called downward determination, macro-determination and
so forth) is the claim that in a complex systems exhibiting emergence, the higher or
macro-level as the locus of emergent phenomena exerts some kind of causal influence downwards on the lower level substrates in the system from which the emergent emerged. But we can appreciate that even in such a simple way of stating it, the
notion of downward causation carries with quite a bevy of problematic issues. What
do “higher” and “lower” levels refer to? What constitutes a substrate in contrast to a
macro-phenomenon? What does “downwards” in this sense mean? What constitutes
a “causal influence”? Furthermore, it is possible to hold the position of accepting at
least some form of emergence but not downward causation or only accepting downward causation if the “causative” action is limited to being the work of some kinds of
constraints or of dumping the whole notion of emergence if downward causation is
legitimated by it or if the whole idea is interpreted as only figurative and not literal.
Any discussion of downward causation will therefore by necessity bring with it
a host of connected issues. And because of the mélange of topics involved, there is
little likelihood of any kind of consensus-based resolution. Nevertheless one promising place to start examining downward causation is to consider within which contexts
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the idea was first prompted and how it was at that time formulated. Such is one of
the reasons for publishing here in E:CO Donald Campbell’s short but powerful early
theory of evolution-based take on downward causation.
Campbell’s Evolution Inspired Downward Causation
First Campbell affirmed his contention that the natural world contained factuallybased hierarchies, not mere arbitrary schemes of classification, for instance, the stratification of molecules, cells, tissues, organs, organisms, populations, species… These
are genuine levels since they have real effects “each of the higher orders organizing
the real units of the lower level”, Campbell here asserting his reductionist leanings in
the midst of both reductionists and anti-reductionists at the conference from which
the book originated. Any manifestation of teleonomy in higher levels must be implemented through lower level “mechanisms and processes”.
Yet, despite this reductionist tendency, Campbell acceded to what he considered
an emergentist position (the “special sciences” aspect of emergentism), namely, that
biological evolution in its “meandering” course comes upon laws which are not adequately described by resort to the lower level units of physics or inorganic chemistry. Instead, there are the “higher laws” operative within the boundaries of each of
the special sciences (for instance, biology, geology, psychology, …) which are specific
to each science’s domain. Downward causation occurs when “the laws of the higherlevel selective system determine in part the distribution of lower level events and substances.” Furthermore, for Campbell, “intermediate-level phenomenon”, what I call the
mesoscopic realm, are not sufficiently understood by reference to “lower level terms”.
This is for Campbell another way of stating that the lower level is constrained by the
upper levels not just the upper is constrained by the lower although, I might add, the
mode and method of constraints are different. Moreover, he was deliberately cautious
in introducing the term “causation” in “downward causation” since he wanted causation as such to extend over biological time, to include several reproductive generations so that we can see that it is evolution that is the issue.
Campbell offered an example of what he meant by downward causation: how the
jaws of a worker termite came to be. The hinges and muscles and their attachments
must conform with Archimedes’s laws of levers, the design of which enabled them
to apply a maximum force at an appropriate distance from the hinge. Although the
design of the jaws had to adhere to laws of physics, it did so in a different way than
the proteins of the jaws muscles. In terms of the overall selective system at the level
of the whole organism the laws of levers are one crucial component. Selection at that
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particular level in the hierarchical level of the organism has optimized the functionality
of the jaw. Yet, a careful look at this reveals that it is necessary to appeal to the law of
levers at the organism level of selection to explain the distribution of the proteins in
the jaw muscles as well as in the dna template for the jaw. Campbell says this is the
same as Dobzhansky’s point that selection is of phenotypes not genotypes. It is the
protein distribution in the jaw that is selected for and not the dna directly.
At this juncture, Campbell brought in something he believed was even more striking: the jaws of the soldier termite where the jaws are so specialized in their function
of piercing enemy termites, antler pincers, that a solider termite cannot feed herself
but requires to be fed by other worker termite. But this implied that it was the hierarchical level of a society which had to enter the explanatory principle since selection is
now following from such societal factors as the division of labor in the termites’ social
milieu. Indeed, this kind of phenomena seems to be a case of convergent evolution
since it has been observed in other social settings as well.
Campbell summed-up his position on downward causation:
…where there is a node of selection at a higher level, the higher level laws are necessary
for a complete specification of phenomena at both the higher level and also for lower
levels.
He explicitly stated he was not pushing for autonomy of higher level only for its necessary locus for an influence downward.
REFERENCES
Campbell, D.T. (1974). “Evolutionary epistemology,” in P. Schilpp (ed), The Philosophy of Karl R.
Popper, ISBN 9780875481418, pp. 412-463.
Gontier, N. (2006). “Donald Campbell,” Internet Encyclopedia of Philosophy, http://www.iep.
utm.edu/evo-epis/#SSH5b.iii.
“Donald T. Campbell,” Wikipedia, http://en.wikipedia.org/wiki/Donald_T._Campbell.
“Teleonomy,” Wikipedia, http://en.wikipedia.org/wiki/Teleonomy.
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