This chapter will describe the research conducted by cognitive scientists who study scientific thinking and reasoning. Surprisingly few of these studies have been conducted using actual scientists. In this chapter, we will find out why. We will also learn more about terms like 'mental model' and 'heuristic' that were used in Chapter 1. We will also try to show, by way of contrast, how science can be studied from other perspectives, particularly the wide range of view loosely identified as having to do with the sociology of scientific knowledge (SSK).
History, philosophy and sociology have strong sub-disciplines associated with the study of science. There is no equivalent in psychology--instead, there are scattered practitioners who do psychology research relevant to science, but very few take on a professional identity as psychologists of science. As a consequence, psychology's contributions to the study of science--and invention, as we will see in subsequent chapters--is not as great as sociology and philosophy because these disciplines have carved up the study of science in a way that appears to exclude cognitive psychology. It is worth providing a brief thumbnail sketch of how this state of affairs came to pass--call it a mythical reconstruction, in the best Campbellian sense, because any account like this is a great oversimplification of a much more complicated story.
Philosophy of science before Kuhn assumed the underlying logic of science is what is really important, not the mental processes of individual scientists. The information is out there in the world; all we have to do is see it, and while there may be interesting stories to tell about how perception works, physiologically, and why it and other psychological processes lead to occasional errors, basically, science is a rational progression towards truth. For example, Karl Popper saw little rationality in the way in which scientists arrived at their conjectures about the universe and its laws, but the way in which their ideas were subjected to testing by the scientific community had to be rational. According to Popper, science advances by discarding false hypotheses and replacing them with ones that are better approximations to the truth , a kind of asymptotic progression where science never arrives at a final, absolute truth but does come gradually closer and closer (Popper, 1959)(Popper, 1992). This distinction between discovery and justification allowed philosophers like Popper to bracket psychological processes and ignore them.
The historian of science Thomas Kuhn, in contrast, put the way a scientist represented the universe of possible choices at the center of his philosophy of science *(Kuhn, 1962). This emphasis on mental representations is also central to cognitive psychology, which in many ways is the study of how we represent the world.
According to Kuhn, he was working on a disseration in theoretical physics when he took a course on physics for the non-scientist that included a strong component of history of science.
To my complete surprise, that exposure to out-of-date scientific theory and practice radically undermined some of my basic conceptions about the nature of science and the reasons for its special success.
These conceptions were ones I had previously drawn partly from scientific training itself and parly from a long-standing vocational interest in the philosophy of science. Somehow, whatever their pedagogic utility and their abstract plausibility, those notions did not at all fit the enterprise that historical study displayed. Yet there were and are fundamentals to many discussions of science, and their failures of versimillitude therefore seemed thoroughly worth pursuing. The result was a drastic shift in my career plans, a shift from physics to history of science and then, gradually, from relatively straightforward historical problems back to the more philosophical concerns that had initially led me to history *(Kuhn, 1962, p. 5).
Kuhn had heard a hero's call to a journey that ended-up transforming science studies. The textbook accounts of science he read in graduate school and the rational reconstructions by philosophers of science did not square with historical accounts of how scientific discoveries actually occurred. Kuhn decided that most of the time, scientists do what he called normal science--they work within the framework of a paradigm, which suggests what kinds experiments are most promising and how to interpret the results. Philosophers have criticized Kuhn for the vagueness of this concept (Masterman, 1970), but its vagueness is its strength.
Kuhn felt scientists learned their paradigm through exemplars.
It was Kuhn's crucial insight that the fundamental units of scientific knowledge are not theories, nor even theories and associated observations, but solved problems. Problem solutions are the irreducible units of resource in scientific research: they are the models on the basis of which further problems are solved. Some of these problem solutions come to be recognized as holding a special promise for future research, and become accepted as authoritative bases for its practice in specific disciplines or specialties in science. These are exemplary achievements or paradigms. In them, theoretical discourse, practice and instrumentation are linked together and grasped in operation: they are understood in use in a way that they could not be understood by abstract consideration" (Barnes, Bloor, & Henry, 1996, pp.101-2).
To use the language of situated cognition, the kind of scientific knowledge represented by exemplars is embodied in devices and fine-grained experimental procedures which shape the sorts of experiments and observations scientists in a particular field conduct, and how they interpret them.
Those who give Kuhn's ideas a radical interpretation hold that the notion of a paradigm is consonant with the cultural beliefs and ritual practices of primitive tribes (Pinch, 1997). Scientists operating within a paradigm don't see it as a hypothesis, subject to test and change; the paradigm corresponds to the way the world is. Before Kepler, the planets moved in perfect circles. Before Lavoisier, burning produced phlogiston. Lavoisier not only created a new theoretical framework; he also provided exemplary experimental procedures. Faraday's portable electromagnetic motor is another exemplar. Eventually, scientists like these generate enough anomalous results to precipitate a paradigm shift., where an anomalous result is something that does not fit within the existing paradigm--like the orbital data for Mars generated by Tycho Brahe.
Kuhn used research in Gestalt psychology to explain what happens when a paradigm shift occurs. Gestalt psychologists thought that in perception, the whole was greater than the sum of its parts. If one changed a small element of a scene, it could suddenly change the way the whole scene was perceived. Kuhn cited an experiment in which the psychologists Bruner and Postman showed participants ordinary playing cards at brief exposures. This kind of brief exposure design is often used in perception experiments to test more automatic perceptual processes. But, as the Gestaltists often showed in their experiments, even brief, 'automatic' processes depend on expectations. In this experiment, some of the playing cards were anomalous, e.g., a black four of hearts. Participants took much longer to recognize these cards. Kuhn quoted one comment, "I can't make the suit out, whatever it is. It didn't even look like a card that time. I don't know what color it is now or whether it's a spade or heart. I'm not sure I even know what a spade looks like. My God!" *(Kuhn, 1962, pp. 63-4).
To Kuhn, this kind of dramatic shift in representation is at the core of scientific revolutions. Kepler certainly experienced it when he abandoned the universe of perfect circles. Empirical evidence is still central to Kuhn's view. Anomalous results have to pile up before a paradigm shift can occur. But there is still room for psychological explanations of why the anomalies trigger a representational crisis in a Kepler or an Einstein and not others, of how others then become convinced to abandon the old paradigm.
According to our mythically-oversimplified account, sociologists of science before Kuhn were more concerned with accounting for the kinds of norms that governed scientific conduct, and also for the way in which non-scientific political and ideological interests accounted for the errors that scientists made (Barnes, Bloor, & Henry, 1996). In other words, reality, was a sufficient explanation for why scientists eventually discovered aspects of the structure of the universe. Robert K. Merton, one of the fathers of sociology of science, argued that, "specific discoveries and inventions belong to the internal history of science and are largely independent of factors other than the purely scientific" (Merton, 1970).
Sociology might be used to explain why Kepler took so long to discard the perfect circle dogma and also why not all scientists immediately embraced his view. The Catholic church's resistance to heliocentric models would be such a factor. Here we have sociology as a way of explaining why the right answer, scientifically speaking, wasn't immediately obvious to everyone. This takes us back to BACON--if a computer can find Kepler's laws in a few minutes, and a group of college students in a few hours, why did it take civilization so long? Must be sociology.
This kind of sociology is certainly very important, but more recently, sociologists of science have tried to understand how scientific knowledge is created, regarding reality as an insufficient explanation. Kuhn drew an explicit analogy between scientific and political revolutions, thus opening the door to a consideration of how sociology shapes scientific knowledge. A new Sociology of Scientific Knowledge (SSK) gradually emerged as a kind of paradigm for studying science, at least among certain sociologists and anthropologists. I use the word 'paradigm' here loosely--SSK is a term which covers many different approaches, and there are sociologists who regard SSK as anathema. But from the standpoint of our almost mythically-oversimplified reconstruction, SSK made the radical assumption that the creation and dissemination of scientific knowledge were proper objects of sociological study. The corollary assumption was that scientific knowledge was at least in part constructed through social negotiations.
These ideas have been controversial, to say the least. To some critics, it sounded as if SSK were undermining the idea of scientist as discoverer of truth--instead, we might substitute scientist as skilled manipulator of social networks, with the end result having no more absolute validity than any other socially-accepted custom. Let us consider this issue in more detail.
This page was last edited: Wednesday, July 14, 1999