RYAN D. TWENEY
Professor of Psychology
General Information ||
My Recent Research on Michael Faraday ||
Personal Info ||
Selected Publications ||
Graduate Students, Past & Present ||
I am Professor of Psychology at Bowling Green State
University, Ohio, where I have been part of the BGSU faculty since 1970. Effective in May, 2005, I assumed
the status of Emeritus Professor, and I am currently dividing my time between Bowling Green and our home in
Beatty, Nevada -- a good place to indulge our love of Death Valley! Currently, I am continuing my work on
Michael Faraday and a recent series of studies on the cognitive underpinnings of religious belief and its
relationship to scientific thinking.
I began my education in psychology at the University of Chicago and then moved on to Wayne State University,
where I specialized in cognitive-experimental psychology, with an emphasis on psycholinguistics. I received
my Ph.D. from Wayne in 1970. My research and teaching interests seem diverse, but actually all are directed
toward a single end -- understanding the nature of scientific thinking. Toward that end, I have done research
using laboratory tasks that simulate scientific inference, historical-cognitive case studies of Michael
Faraday's research diaries, computational modeling of scientific inference, and historical studies of
"psychological science." I think of myself as both "practicing scientist" and "practicing scholar." In fact,
one of my present concerns is to develop the argument that cognitive science is essentially incomplete unless
it incorporates the kind of interpretive analysis that characterizes history and cultural studies. In part, my
convictions in this respect have been shaped by what I have learned from my students.
More about my interests can be found in the interview published in Werner Callebaut's book, listed in my
publications as "Tweney (1993)".
MY RECENT RESEARCH ON MICHAEL FARADAY
In 1998, while on a visit to the Royal Institution of Great Britain in London,
I noticed what seemed to be a few microscope slides in the Michael Faraday museum area. The following year, I
returned to examine these slides, and, with the help of Dr. Frank A.J.L. James, Reader in the History and
Philosophy of Science at the RI, we removed the slides from the museum area. The result was astonishing: almost the
entire set of specimens used by Faraday in his 1856 research on the properties of gold metallic films; more than
600 specimens in all! Gold films interested Faraday because, if thin enough, they manifest a different color by
transmitted light than by reflected light; green, blue, and purple are the most frequent transmitted colors for gold
leaf. Faraday thought that gold was therefore a good place to look for insight into the interactions of matter and
light. For him, the profoundly interesting question concerned the manner in which such very thin (and apparently
continuous) films could so alter light.
During the course of this project he discovered and prepared the first-ever metallic colloids,
an example of one of which still exists
and is still striking. "Colloids" (the term was first coined by Thomas Graham in 1861) are finely divided particles
of a substance held in suspension in a fluid; Faraday's discovery that metals could form colloids was a breakthrough,
especially since he also showed that the particles were composed of the pure metal, chemically the same stuff as the
metal films. Colloids differ from solutions in that solutions represent ionized particles of atomic size, carrying an
electrical charge. Ions (coincidentally, the term "ion" was introduced by Faraday, in the 1830s), the particles that
form a solution, are much smaller than colloidal particles, which, because they are larger, affect light in different
ways than do solutions (see below for an image and an example). We have been replicating some of Faraday's
preparations in our lab. The image below shows three preparations; from left to right, they are: a gold colloid, a
solution of gold chloride, and precipitated gold (prepared by adding ferrous sulfate to gold chloride). A parallel
beam of light is entering from the left. The particles in a precipitate are much larger than those in a colloid, but
notice that the precipitate scatters light -- as does the colloid!
The near-complete slide set means that, together with Faraday's diary record, his publications on the topic, and our
ability to replicate his preparations, we now have what is one of the most complete records anywhere of the course of
a great scientist's research. Since finding this material, I have turned my major research efforts toward understanding
Faraday's research on gold and other metals; the first results were presented at a conference in Pavia, Italy, in May,
2001. A chapter based upon the talk is is available
here in PDF format.
Several other papers and chapters on this topic have recently been published and will soon be available here in pdf
format. So far, I have completed a catalog of the surviving specimens, have documented photographically a number of
them, and we are beginning to "digitize" the relevant diary records, which will then be photographically illustrated
with images of the specimens. In addition, we replicated some of the chemical procedures used by Faraday, in order to
uncover aspects of his tacit knowledge. In the end, a uniquely complete cognitive model of his research should be
Some of Faraday's slides are of striking beauty, for example, Slide No. 181:
This slide looks even better at 70x magnification:
Or, consider Slide No. 42, which shows four leaves of gold (each a light blue by transmitted light) mounted one over
the other. On most monitors, the difference between the two darkest films will not be apparent; but there really are
four shades of blue on this slide! The slide (and others of a similar character) told Faraday that mere thickness of
the film was not responsible for its overall color.
At 70x magnification, this slide is also strikingly beautiful. The image was taken near an edge, and now the four
different blues should be readily visible.
Another example of one of the slides (Slide No. 194) can be seen
Notice that its appearance is very different by reflected light and by transmitted light. This is even more true of
Slide No. 410, seen here:
These examples should make clear that Faraday was dealing with an issue of very wide scope. The spectacular range of
colors manifested by gold is, in fact, just an extension of the peculiar behavior of metals in general; why do
they look shiny? Faraday's attempt to understand how the microstructure of metals affects their appearance was
ultimately unsuccesful, but the directness of his methods -- and the findings he did make -- remain important and
Together with Ryan Mears and Andy Wickiser, I am now working to replicate some of Faraday's procedures. For example,
we have prepared gold colloids that closely resemble Faraday's. In the image below, a beam of light is being passed
through a solution of gold chloride (on the left) and one of our gold colloids (on the right). Notice the
"Faraday-Tyndall Effect," that is, that the colloid scatters light to the side, unlike the solution. It is interesting
that the same overall amount of gold is present in both flasks, but the optical behavior differs because the physical
arrangement of the gold particles is so different.
At the end of his research on gold, Faraday concluded that all of the effects were consistent with the particulate
effects of gold; contrary to his initial expectations, the evidence nowhere allowed him to assert that gold was a
continuous film in a true sense. Yet this somewhat negative-sounding conclusion does not tell the entire story.
Faraday had obtained evidence that the effects of the very small particles of gold on light were not produced by
singular particles, but rather by arrays of particles. In effect, the colorful effects of gold were the result of
something that happened between particles, and they spoke to him, therefore, of the presence of field-like interactions
between matter and light. For the pre-eminent field theorist of the time, this must have been an exciting conclusion.
Here is an example of how we might be able to uncover the cognitive practices of Faraday. Consider
Faraday's Slide No. 124. Faraday prepared
this slide by first mounting an ordinary gold leaf on a slide, then thinning it by using hydrochloric acid to dissolve
away trace amounts of other metals usually found in gold leaf, like copper and zinc. However, Faraday's attention was
caught by a peculiar structure in one part of the slide, visible to us at about 10x magnification
here. Note the odd square structure! In fact, a
kind of black "Chinese Wall" (Faraday's term) leads off to the lower left. At higher magnification,
this structure does indeed resemble an
architectural artifact. Faraday puzzled over this structure's oddly precise geometric form without ever reaching
conclusions about its nature. We managed to produce a similar structure, this time by thinning a gold leaf slide with
aqua regia, and indeed the structure is a puzzling one to find on one part of a slide which otherwise looks unremarkable.
From a cognitive point of view, there is more here than simply a failure to understand a phenomenon. Note, first of all,
that Faraday is here engaged in an exploration, rather than in a finished,hypothesis-testing, experiment. Slide 124 is,
in effect, posing a question, rather than an answer! Specifically, Faraday has "noticed" something that suggests a
question. Why? Why should this particular slide possess properties that attracted his notice? The answer resides in what
he saw as the remarkable regularity of the structure on the slide, a regularity that could have reminded him of the
cell-like organization of living material. Nor is this a superficial resemblance, especially recalling that some of his
earlier work on electrostatic lines of force was inspired by research with an electric fish (a "Gymnotus," that could stun
its prey with a high-voltage charge). In his work on gold, there are also indications that analogies from the organic
world are attracting his attention, and this seems to be such a case. Why, he appears to ask, do some clearly non-living
substances manifest structures seen commonly in living substance alone? Is this question the truly important one?
Slide No. 124 is an easy case, in a sense, because Faraday never was able to answer the question of how such a structure
was produced, nor of what importance it might have; the available evidence for a cognitive "story" is very limited. For us,
then, the cognitive account is relatively easy; we have one event, one slide that he has singled out, and no followup. In
other cases, we will have a great deal more to do!
In addition to my own research, I am privileged to have supervised graduate students in their studies; 14 dissertations
have been completed under my direction. Each is listed below, along with the title of their dissertation and most recent
affiliation (as known by me; some may be incorrect!). Each Ph.D. was in Psychology, except for two in American Culture
Yanlong Sun, Ph.D. 2002. Cognitive Science Program, College of Computing, Georgia
Institute of Technology. The 'Hot Hand' revisited: An exploration in Cognitive Statistics.'
Maria Ippolito, Ph.D. , 1998. University of Alaska at Anchorage. "
Capturing the flight of the mind;" Creative problem solving in the novels of Virginia Woolf.
Elke M. Kurz, Ph.D., 1997. College of Computing, Georgia Institute of
Technology. Representational practices of differential calculus: A historical cognitive approach.
Tamela Bresler, Ph.D., 1995. U.S. Air Force Medical Services, Lackland AFB,
Davis, CA. The role of experience in parental problem-solving tasks: Visual processing of parent-child interaction
and reasoning about discipline.
Helfried Zrzavy, Ph.D., 1995 (American Culture Studies) Mariposa Museum, Peterborough, NH. Erik H. Erikson's
epiphanies: An interpretive-interactionist study of select aspects of his life and work.
Duane Vorhees, Ph.D., 1990 (American Culture Studies) University of Maryland
(Asia Division), Seoul, South Korea. A cultural and intellectual biography of Immanuel Velikovsky.
Wei Chia, Ph.D., 1990. IBM Corporation, An analysis of expert witness cognition in developing strategies for
employment discrimination cases.
Carol Tolbert, Ph.D., 1989. Department of Energy, Can a reduced selection task be used to induce disconfirmatory
Bonnie Walker, Ph.D., 1987. Texas Juvenile Crime Prevention Center, Prairie
View A&M Unievrsity, Houston, Texas. A comparison of the psychological effects of the possibility of error and
actual error on hypothesis testing.
Steve Yachanin, Ph.D., 1982. Lake Erie College, Painesville, OH.
Cognitive short-circuiting strategies: The path of least resistance in inferential reasoning.
Patricia Petretic-Jackson, Ph.D., 1981.
University of Arkansas, Fayetteville, AK. Children's acquisition of a miniature linguistic system: A comparison of
signed and spoken languages.
Mark Stevens, Ph.D., 1981. University of Dubuque,
Dubuque, IA. Hypothesis testing in elderly as a function of task concreteness and memory condition.
D. Robert Aiello, Ph.D., 1978. Senior Services, Rio Rancho, NM. Selective reminding and retrieval in the elderly.
Gary W. Heiman, Ph.D., 1977. State College of New York
at Buffalo, Buffalo, NY. The intelligibility and comprehension of time compressed American Sign Language.
M.E. Gorman, R.D. Tweney, D.C. Gooding, & A.P. Kincannon (Eds.) (2005). Scientific and technological
thinking. Mahwah, NJ: Lawrence Erlbaum Associates.
J. Popplestone & R.D. Tweney (Eds.) (1998). C.H. Stoelting Co., Psychological and physiological
apparatus and supplies. Chicago, IL: C.H. Stoelting Co., 1930. Reprinted and edited, with an Introduction
by ... Ann Arbor, MI: Scholar's Facsimiles and Reprints.
R. D. Tweney & D. Gooding (Eds.). (1991). Faraday's 1822 "Chemical Notes, Hints, Suggestions, and
Objects of Pursuit". Edited with an introduction and notes by R. D. Tweney & D. Gooding. London: The
Science Museum & Peter Peregrinus, Ltd.
R. D. Tweney, M. E. Doherty, & C. R. Mynatt (Eds.). (1981). On scientific thinking. New York:
Columbia University Press.
W. Bringmann & R. D. Tweney (Eds.). (1980). Wundt studies: A centennial collection. Toronto: C. J.
Selected Published Papers (Journals and Book Chapters)
R.D. Tweney (2004). Replication and the experimental ethnography of science. Journal of Cognition and
Culture, 4(3), 731-758. Available as a pdf
R.D. Tweney (2001). Toward a general theory of scientific thinking. In K. Crowley, C.D. Schunn, & T. Okada
(Eds.) Designing for science: Implications from professional, instructional, and everyday science.
Mahwah, NJ: Erlbaum
E.M. Kurz & R.D. Tweney (1998). The practice of mathematics and science: From calculus to the clothesline
problem. In M. Oaksford & N. Chater (Eds.) Rational models of cognition, 415-438. Oxford: Oxford
R.B. Anderson & R.D. Tweney (1997). Artifactual power curves in forgetting. Memory & Cognition, 25,
R.D. Tweney (1997). Jonathan Edwards and determinism. Journal for the History of the Behavioral Sciences,
33, 365-380. Available as a pdf
R.D. Tweney & S.C. Chitwood (1995). Scientific Reasoning. In S. Newstead & J. St. B. T. Evans (Eds.)
Perspectives on thinking and reasoning: Essays in honour of Peter Wason, (pp. 241-260). Hove, East
Sussex: Lawrence Erlbaum Associates.
M.F. Ippolito & R.D. Tweney. (1995). The inception of insight. In R.J. Sternberg & J.E. Davidson
(eds.) The nature of insight (pp. 433-462). Cambridge, MA: The MIT Press.
R. D. Tweney (1994). On the social psychology of science. In W. Shadish & S. Fuller (Eds.), The
social psychology of science (pp. 352-363). New York: Guilford Press.
R.D. Tweney (1993). Steps toward a cognitive
science of science (interview with R.D. Tweney). In W. Callebaut, Taking the naturalistic turn, Or, How
the new philosophy of science is done (pp. 341-349 and 479, especially, passim elsewhere). Chicago:
University of Chicago Press.
R.D.Tweney. (1992). Inventing the field: Michael Faraday and the creative engineering of electromagnetic
field theory. In D. Perkins & R.Weber (eds.) Inventive minds: Creativity in technology. New
York: Oxford University Press, pp. 31-47.
R. Tweney (1992). Stopping Time: Faraday and the scientific creation of perceptual order. Physis: Revista
Internazionale di Storia Della Scienza, 29, 149-164.
R. D. Tweney (1992). Serial and parallel processing in scientific discovery. In R. Giere (Ed.), Cognitive
models of science (Minnesota Studies in the Philosophy of Science XV). Minneapolis: University of
Minnesota Press, pp. 77-88.
R. Tweney (1991). Faraday's 1822 Chemical Hints notebook and the semantics of chemical discourse. Bulletin
for the History of Chemistry,
No. 11 (Winter, 1991), pp. 51-55.
R. D. Tweney (1991). Faraday's notebooks: The active organization of creative science. Physics Education,
R. D. Tweney (1990). Five questions for computationalists. In J. Shrager & P. Langley (Eds.),
Computational models of scientific discovery and theory formation. Palo Alto, CA: Morgan Kaufmann, pp.
R. D. Tweney. (1989). Fields of enterprise: On Michael Faraday's thought. In D. Wallace, & H. Gruber
(Eds.), Creative people at work: Twelve cognitive case studies. Oxford: Oxford University Press,
R. D. Tweney. (1989). A framework for the cognitive psychology of science. In B. Gholson, A. Houts, R. A.
Neimeyer, & W. Shadish (Eds.), Psychology of science and metascience.
Cambridge: Cambridge University Press, pp.
R. D. Tweney. (1987). Programmatic research in experimental psychology: E. B. Titchener's laboratory
investigations, 1891-1927. In M. G. Ash & W. R. Woodward (Eds.), Psychology in twentieth-century
thought and society. Cambridge: Cambridge University Press, pp. 35-58.
R. D. Tweney & C. E. Hoffner. (1987). Understanding the microstructure of science: An example.
Proceedings of the Ninth Annual Meeting of the Cognitive Science Society. New York: Lawrence Erlbaum,
R. D. Tweney. (1985). Faraday's discovery of induction: A Cognitive Approach. In D. Gooding & F.A.J.L.
James (Eds.), Faraday rediscovered: Essays on the life and work of Michael Faraday, 1791-1867. New
York: Stockton Press/London: Macmillan, pp. 189-210 (Reprinted, 1990, American Institute of Physics).
R. D. Tweney. (1985). Linguistics and psychology in Nineteenth-Century German science. In G. Eckardt, W. G.
Bringmann, and L. Sprung (Eds.), Contributions to a history of developmental psychology: International
William T. Preyer Symposium. The Hague: Mouton & Co., pp. 283-300.
R. D. Tweney & M. E. Doherty. (1983). Rationality and the psychology of inference. Synthese:
International Journal for Epistemology, Methodology, and Philosophy of Science, 57, 139-161.
A. Rucci & R. D. Tweney. (1980). Analysis of variance and the "Second Discipline" of scientific psychology:
An historical account. Psychological
Bulletin, 87, 166-184.
R. D. Tweney, M. E. Doherty, W. J. Worner, D. B. Pliske, C. R. Mynatt, K. A. Gross, & D. L. Arkkelin.
(1980). Strategies of rule discovery in an inference task. Quarterly Journal of Experimental Psychology, 32,
R. D. Tweney. (1979). Reflections on the history of behavioral theories of language. Behaviorism, 7,
C. R. Mynatt, M. E. Doherty, & R. D. Tweney. (1978). Consequences of confirmation and disconfirmation in a
simulated research environment. Quarterly Journal of Experimental Psychology, 30, 395-406.
Professor, Department of Psychology, Bowling Green State University
Scholar in Residence, Institute for the Study of Culture & Society, BGSU
Visiting Fulbright Scholar, University of Bath and Visiting Research Fellow, Royal Institution of Great Britain
Associate Professor, Department of Psychology, Bowling Green State University.
Visiting Associate Research Professor, Laboratory for Language Studies, Salk Institute for Biological Studies
and Visiting Associate Professor, Center for Research in Language Acquisition (Department of Linguistics),
University of California at San Diego.
Assistant Professor, Department of Psychology, Bowling Green State University
Ryan D. Tweney
Department of Psychology
Bowling Green State University
Bowling Green, OH 43403
Office: 360 Psychology Building
Phone: (419) 372-8482 or (419) 372-2301
Fax: (419) 372-6013
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