- PARADIGMS AND PREJUDICES
- Many non-scientists are awed by the power and seeming
certainty of scientific knowledge. So are most students of science. Textbooks
are full of apparently hard facts and quantitative data. Science seems
supremely objective. Moreover, a belief in the objectivity of science is
a matter of faith for many modern people. It is fundamental to the worldview
of materialists, rationalists, secular humanists, and all others who uphold
the superiority of science over religion, traditional wisdom, and the arts.
- This image of science is rarely discussed explicitly
by scientists themselves. It tends to be absorbed implicitly and taken
for granted. Few scientists show much interest in the philosophy, history,
or sociology of science, and there is little room for these subjects in
the crowded curriculum of science courses. Most simply assume that by means
of "the scientific method," theories can be tested objectively
by experiment in a way that is uncontaminated by the scientists' own hopes,
ideas, and beliefs. Scientists like to think of themselves as engaged in
a bold and fearless search for truth.
- Such a view now excites much cynicism. But I think it
is important to recognize the nobility of this ideal. Insofar as the scientific
endeavor is illuminated by this heroic spirit, there is much to commend
it. Nevertheless, in reality most scientists are now the servants of military
and commercial interests. Almost all are pursuing careers within institutions
and professional organizations. The fear of career setbacks, rejection
of papers by learned journals, loss of funding, and the ultimate sanction
of dismissal are powerful disincentives to venture too far from current
orthodoxy, at least in public. Many do not feel secure enough to voice
their real opinions until they have retired, or won a Nobel Prize, or both.
- Popular doubts about the objectivity of scientists are
widely shared, for more sophisticated reasons, by philosophers, historians,
and sociologists of science. Scientists are part of larger social, economic,
and political systems; they constitute professional groups with their own
initiation procedures, peer pressures, power structures, and systems of
rewards. They generally work in the context of established paradigms or
models of reality. And even within the limits set by the prevailing scientific
belief system, they do not seek after pure facts for their own sake: they
make guesses or hypotheses about the way things are, and then test them
by experiment. Usually these experiments are motivated by a desire to support
a favorite hypothesis, or to refute a rival one. What people do research
on, and even what they find, is influenced by their conscious and unconscious
expectations. In addition, feminist critics detect a strong and often unconscious
male bias in the theory and practice of science.
- Many practicing scientists, like doctors, psychologists,
anthropologists, sociologists, historians, and academics in general, are
well aware that detached objectivity is more an ideal than a reflection
of actual practice. In private, most are prepared to acknowledge that some
of their colleagues, if not they themselves, are influenced in their researches
by personal ambition, preconceptions, prejudices, and other sources of
- The tendency to find what is being looked for is deep-seated.
It has a basis in the very nature of attention. The ability to focus the
senses in accordance with intentions is a fundamental aspect of animal
nature. Finding what is looked for is an essential feature of everyday
human life. Most people are well aware that other people's attitudes affect
the way they interact with the world around them. We are not surprised
by such biases in politicians, nor by the differences in the way people
see things within different cultures. We are not surprised to find many
everyday examples of self-deception in members of our families and among
friends and colleagues. But the "scientific method" is generally
supposed to rise above cultural and personal biases, dealing only in the
currency of objective facts and universal principles.
- Biases in science are easiest to recognize when they
reflect political prejudices, because people of opposing political views
have a strong motive to dispute the claims of their opponents. For example,
conservatives like to find a biological basis for the superiority of dominant
classes and races, explaining their differences as largely innate. By contrast,
liberals and socialists prefer to see environmental influences as predominant,
explaining existing inequalities in terms of social and economic systems.
- In the nineteenth century, this "nature-nurture"
debate focused on measurements of brain size; in the twentieth, on measurements
of IQ. Eminent scientists who were convinced of the innate superiority
of men over women and of whites over other races, were able to find what
they wanted to find. Paul Broca, for example, the anatomist after whom
the speech area of the brain is named, concluded that: "In general,
the brain is larger in mature adults than in the elderly, in men than in
women, in eminent men than in men of mediocre talent, in superior races
than in inferior races."3 He had to overcome many factual obstacles
to maintain this belief. For example, five eminent professors at Gottingen
gave their consent to have their brains weighed after they died; when these
cerebral weights turned out to be embarrassingly close to average, Broca
concluded that the professors hadn't been so eminent after all!
- Critics of a more egalitarian political persuasion have
been able to show that generalizations based on different brain sizes or
IQ scores rested on the systematic distortion and selection of data. Sometimes
the data themselves "were actually fraudulent, as in the case of some
of the publications of Sir Cyril Burt, a leading defender of the view that
intelligence is largely innate. In his book The Mismeasure of Man, Stephen
Jay Gould traces the sorry history of these purportedly objective studies
of human intelligence, showing how persistently prejudice has been clothed
in scientific garb. "If -- as I believe I have shown -- quantitative
data are as subject to cultural constraint as any other aspect of science,
then they have no special claim on final truth."4
- PUBLIC PRETENSE
- A persistent and pervasive source of the illusion of
objectivity is the style in which scientific reports are written. They
give the appearance of coming from an idealized world in which science
is an entirely logical exercise, free from all human passion. "Observations
were made . . . ," "It was found that ... . ," "The
data show . . . ," and so on. These literary conventions are still
taught to budding scientists at school and university: "A test tube
was taken. . . ."
- Scientists publish their findings in technical articles,
called papers, in specialized journals. In a justly famous essay called
"Is the scientific paper a fraud?" the immunologist Peter Medawar
pointed out that the standard structure of these papers gives "a totally
misleading narrative of the processes of thought that go into the making
of scientific discoveries." In the biological sciences, a typical
paper starts with a brief introduction, including a survey of previous
relevant work, then a section on "Materials and Methods," followed
by "Results" and finally a "Discussion."
- The section called "results" consists of a
stream of factual information in which it is considered extremely bad form
to discuss the significance of the results you are getting. You have to
pretend that your mind is, so to speak, a virgin receptacle, an empty vessel,
for information that floods in from the external world for no reason which
you yourself have revealed. You reserve all appraisal of the scientific
evidence until the "discussion" section, and in the discussion
you adopt the ludicrous pretence of asking yourself if the information
you have collected actually means anything.5
- In fact, of course, the hypotheses that the experiments
were designed to test generally come first, rather than last. Since Medawar
wrote this passage there has been a greater conscious recognition of this
sequence of events, and an increasing tendency to mention hypotheses in
the introductions to papers. But the same conventions remain: passionless
prose, the use of the passive voice, and the pretense that data are unembellished
facts. Practicing scientists are well aware that this style is a kind of
make-believe; but it has now become obligatory for anyone with pretensions
to objectivity, and has been adopted by technocrats and bureaucrats as
- DECEIT AND SELF-DECEPTION
- The illusion of objectivity is most powerful when its
victims believe themselves to be free of it. Along with a laudable sense
of honor, a tendency to self-righteousness has been present in experimental
science right from the outset.
- With Galileo, the desire to make his ideas prevail apparently
led him to report experiments that could not have been performed exactly
as described. Thus an ambiguous attitude toward data was present from the
very beginning of Western experimental science. On the one hand, experimental
data was upheld as the ultimate arbiter of truth, on the other hand, fact
was subordinated to theory when necessary and even, if it didn't fit, distorted.
A similar vice afflicted other giants in the history of science, not least
Sir Isaac Newton. He overwhelmed his critics with an exactness of results
that left no room for dispute. His biographer Richard Westfall has documented
how he adjusted his calculations on the velocity of sound and the precession
of the equinoxes, and altered the correlation of a variable in his theory
of gravitation to give a seeming accuracy of better than 1 part in 1,000.
- Not the least part of the Prindpias persuasiveness was
its deliberate pretense to a degree of precision quite beyond its legitimate
claim. If the Prindpia established the quantitative pattern of modern science,
it equally suggested a less sublime truth -- that no one can manipulate
the fudge factor so effectively as the master mathematician himself.
- Probably the commonest kind of deception -- and of self-deception
-- depends on the selective use of data. For example, from 1910 to 1913,
the American physicist Robert Millikan was engaged in a dispute with an
Austrian rival, Felix Ehrenfeld, about the charge on the electron. Both
Millikan's and Ehrenfeld's early data were rather variable. They depended
on introducing oil drops into an electric field and measuring the strength
of the field needed to keep them suspended. Ehrenfeld claimed that the
data showed the existence of subelectrons with fractions of a unit electron
charge. Millikan maintained there was a single charge. To rebut his rival,
in 1913 he published a paper full of new, precise results supporting his
own view, emphasizing in italics that "this is not a selected group
of drops but represents all of the drops experimented upon during sixty
- A historian of science has recently examined Millikan's
laboratory notebooks, which reveal a very different picture. The raw data
were individually annotated with comments such as "very low, something
wrong" and "beauty, publish this." The 58 observations published
in his article were selected from 140. Ehrenfeld meanwhile went on publishing
all his observations, which continued to show a far greater variability
than Millikan's selected data. Ehrenfeld was disregarded while Millikan
won the Nobel Prize.
- Millikan was no doubt convinced that he was right, and
did not want his theoretical convictions to be disturbed by messy data.
Probably the same was true of Gregor Mendel, the results of whose famous
pea-breeding experiments were, according to modern statistical analysis,
too good to be true.
- The tendency to publish only the "best" results
and to tidy up data is certainly not confined to famous figures in the
history of science. In most if not all areas of science, good results are
likely to advance the career of the person who produces them. And in a
highly competitive and hierarchical professional environment, various forms
of improving the results are widely practiced, if only by omitting unfavorable
data. This practice is indeed normal. Apart from anything else, journals
are disinclined to publish the results of problematical or negative experiments.
Little professional credit results from unclear data or seemingly meaningless
- I know of no formal study on the percentage of research
data that are actually published. In the fields I know best from personal
experience -- biochemistry, developmental biology, plant physiology, and
agriculture -- I estimate that only about 5-20 percent of the empirical
data are selected for publication. I have asked colleagues in other fields
of inquiry, such as experimental psychology, chemistry, radioastronomy,
and medicine, and come up with similar results. When the great majority
of the data are discarded in private processes of selection -- often 90
percent or more -- there is obviously plenty of scope for personal bias
and theoretical prejudice to operate both consciously and unconsciously.
- The selective publication of data creates a context in
which deception and self-deception become a matter of degree. Moreover,
scientists usually regard their research notebooks and data files as private,
and tend to resist any attempts by critics and rivals to go through them.
True, it is usually assumed that a researcher will, within reason, make
his or her data available to any colleague who might express a desire to
see them. But in my own experience, this ideal is far from the reality.
On the several occasions I have asked researchers if I may see their raw
data, I have been refused. Maybe this says more about me than about prevailing
scientific norms. But one of the very few systematic studies of this cherished
principle of openness gives little ground for confidence. The procedure
was simple. The person conducting it, a psychologist at Iowa State University,
wrote to thirty-seven authors of papers published in psychology journals
requesting the raw data on which the papers were based. Five did not reply.
Twenty-one claimed that their data had unfortunately been misplaced or
inadvertently destroyed. Two offered access only on very restrictive conditions.
Only nine sent their raw data; and when their studies were analyzed, more
than half had gross errors in the statistics alone.
- Those who refuse to expose their raw data to scrutiny
may well have nothing to hide; they may simply find it inconvenient to
explain their notes to someone else, or suspect the motives for the request,
or resent an implied slur on their honor. It is not the purpose of this
discussion to suggest that scientists are particularly prone to deliberate
fraud and deception. On the contrary, most scientists are probably at least
as honest as most members of other professional groups, such as lawyers,
priests, bankers, and administrators. But scientists have greater pretensions
to objectivity, and at the same time a culture which encourages the selective
publication of results. These conditions are favorable for the deliberate
deception of others, but I do not see this as the most important threat
to the ideal of objectivity. Self-deception is the greatest danger, especially
collective self-deception encouraged by dominant assumptions about objective
- Many scientists recognize the potential for wishful thinking
in others and are quick to dismiss results of research in unorthodox fields
such as parapsychology and holistic medicine as due to self-deception,
if not deliberate fraud. And indeed some of those who challenge orthodox
ideas may well deceive themselves. But they do little harm to the progress
of science because their results are either ignored, or else subjected
to extremely critical scrutiny. Organized groups of Skeptics, such as CSICOP,
the Committee for the Scientific Investigation of Claims of the Paranormal,
are always ready to challenge results that do not fit into the mechanistic
worldview, and try their best to discredit them. Parapsychologists are
so accustomed to these critical responses that they are unusually aware
of the pitfalls of experimenter effects and other sources of bias. But
conventional science is not subject to a similar degree of sceptical scrutiny.
- PEER REVIEW, REPLICATION, AND FRAUD
- Scientists, like doctors, lawyers, and other professionals,
generally resist attempts by outside agencies to regulate their conduct.
They pride themselves on their own system of controls. These are threefold:
- Applications for jobs and grants are subject to peer
review, ensuring that the researchers and their projects meet with the
approval of established professionals.
- Papers submitted to scientific journals have to pass
the critical scrutiny of expert referees, usually anonymous.
- All published results are potentially subject to independent
- Peer review and refereeing procedures do indeed act as
important quality checks, and are no doubt often effective, but they have
a built-in bias. They tend to favor prestigious scientists and institutions.
And independent replication is in fact rarely performed, for at least four
reasons. First, in practice it is difficult to replicate a given experiment
exactly, if only because the recipes are incomplete or fail to communicate
practical knacks. Second, few researchers have the time or resources to
repeat other people's work, especially if the results come from a well-funded
laboratory and involve expensive apparatus. Third, there is usually no
motivation for replicating the work of others. And fourth, even if exact
replications are performed, it is difficult to get them published because
scientific journals favor original research. Replication of other people's
results is usually attempted only under special conditions, for example
when the results are of unusual importance or when fraud is suspected on
- Under these circumstances deceptions can easily pass
unchallenged as long as the results are in accordance with prevalent expectations.
- Acceptance of fraudulent results is the other side of
that familiar coin, resistance to new ideas. Fraudulent results are likely
to be accepted in science if they are plausibly presented, if they conform
with prevailing prejudices and expectations, and if they come from a suitably
qualified scientist affiliated with an elite institution. It is for the
lack of all these qualities that new ideas in science are likely to be
resisted. Only on the assumption that logic and objectivity are the sole
gatekeepers of science is the prevalence and frequent success of fraud
in any way surprising. . . . For the ideologists of science, fraud is taboo,
a scandal whose significance must be ritually denied on every occasion.
For those who see science as a human endeavor to make sense of the world,
fraud is merely evidence that science flies on the wings of rhetoric as
well as reason.
- One of the few areas of science subject to a limited
form of external supervision is the testing for safety of new foods, drugs,
and pesticides. In the United States, every year many thousands of test
results are submitted by industry for review by the Food and Drug Administration
(PDA) or the Environmental Protection Agency (EPA). These agencies have
the power to send inspectors to the laboratories that provide the data.
They continually unearth falsified results.12
- The cases of fraud uncovered in the great unpoliced hinterlands
of science are rarely brought to light by the official mechanisms of peer
review, refereeing of papers, and the potential for independent replication.
And even if attempts to replicate an experiment fail, this is usually ascribed
to a failure to reproduce the conditions of the experiment precisely enough.
There is a big psychological and cultural barrier against accusing colleagues
of fraud -- unless one has strong personal reasons to suspect their integrity.
Most known cases of fraud come to light as a result of whistle-blowing
by immediate colleagues or rivals, often as a result of some personal grievance.
When this happens, the typical response of laboratory chiefs and other
responsible authorities is to try to hush the matter up. But if the charges
of fraud do not blow over, if allegations are made persistently enough,
and if the evidence becomes overwhelming, then an official inquiry is held.
Someone is found guilty and dismissed in disgrace.
- Most professional scientists deny that these incidents
shed doubt on institutional science as a whole; rather, they are seen as
isolated aberrations by individuals who have become temporarily unhinged
under pressure, or who are rare but inevitable psychopaths. Science is
purified by their expulsion. They are scapegoats in the biblical sense.
On the Day of Atonement the high priest confessed the sins of the people
while laying his hands on a goat. The guilt-laden scapegoat was then expelled
from the community into the wilderness, bearing away their iniquities.
- Scientists generally feel the need to preserve an idealized
self-image, not just for personal and professional reasons, but also because
this image is projected on to them by others. There are many people who
put their faith in science rather than religion, and need to believe in
its superior, objective authority. And to the extent that science replaces
religion as the source of truth and values, then scientists become a kind
of priesthood. As with priests in general, there is then a public expectation
that they will live up to the ideals they preach: in the case of scientists,
objectivity, rationality, and the quest for truth. "Some scientists,
in their public appearances, can be noticed playing up to this role, which
seems to invest them as cardinals of reason propounding salvation to an
irrational public." There is also a strong disincentive for them to
admit that there is anything fundamentally wrong with the beliefs and institutions
that legitimize their own position. While it is relatively easy to admit
that individuals may err, and to purify the community by expelling them,
it is much harder to question the beliefs and idealizations on which the
whole system depends.
- Philosophers of science tend to idealize the experimental
method, and so do scientists themselves. In their insightful study of fraud
and deceit in science, William Broad and Nicholas Wade were led to inquire
what actually happens in laboratories, as opposed to what is supposed to
happen. They found that the reality was far more pragmatic and empirical,
involving much trial and error:
- The competitors in a given field try many different approaches
but are always quick to switch to the recipe that works best. Science being
a social process, each researcher is trying at the same time to advance
and gain acceptance for his own recipes, his own interpretation of the
field. ... Science is a complex process in which the observer can see almost
anything he wants provided he narrows his vision sufficiently. . . . Scientists
are individuals and they have different styles and different approaches
to the truth. The identical style of all scientific writing, which seems
to spring from a universal scientific method, is a false unanimity imposed
by the current conventions of scientific reporting. If scientists were
allowed to express themselves naturally in describing their experiments
and theories, the myth of a single, universal scientific method would probably
- I agree with this analysis. This present book is an argument
for more democratic and pluralistic scientific research, liberated from
the conventions imposed upon institutional science by its role as the Established
Church of the secular world order. But whatever forms science takes, it
will still depend on experiments.
- EXPERIMENTS ON EXPERIMENTS
- So far in this discussion I have considered the general
problems caused by the illusion of objectivity. In the following two chapters
I outline experiments to investigate the nature of experimental research
- In chapter 6, I consider the doctrine of uniformity,
which biases scientists against seeing unexpected patterns or irregularities
in nature. Even the constancy of the "fundamental constants"
turns out to be a matter of faith. These constants, as actually measured,
fluctuate. Treating variations as random errors enables the data to be
smoothed out, concealing underlying variations behind a uniform facade.
I suggest a way in which these observed variations can be investigated
- In chapter 7, I turn to the influence of the expectations
of experimenters on experiments themselves. These may well include subtle
influences, perhaps including paranormal effects, on the system under study.
How much do experiments tell us about nature, and how much do they merely
reflect the expectations of the experimenter?