Cernovsky, Z. Z. (1997)
A critical look at
intelligence research,
In Fox, D. &
Prilleltensky, I. (Eds.) Critical Psychology, London: Sage, ps 121-133.
Psychology's
support for an unjust status quo has taken many forms over the years. As noted
in several chapters in this book, one important form is the use of
psychological tests to explain - in effect, to justify - a lack of societal
equality. Administering and interpreting intelligence tests are primary
examples of how the routine work of mainstream psychologists can hinder
progress toward social justice. Because psychological tests are research
tools," the public often assumes that their results or interpretations are
infallible. This assumption is a mistake, one with serious negative
consequences for members of groups seen as
genetically inferior" as "proven" by "science."
Psychologists, educators, psychiatrists,
and the lay public often misunderstand intelligence as consisting exclusively
or primarily of the skills assessed by modem tests of intelligence. These IQ
(intelligence quotient) tests have an excessively narrow focus on skills and
tasks acquired and rehearsed in the process of formal or informal schooling.
The narrow focus prevents these tests from detecting other crucial ingredients
of intelligence such as creativity or social intelligence (the ability to
understand, accurately perceive, and influence emotional states and social
behavior of others).
These IQ test limitations have historical
roots. The first generally accepted intelligence test was devised for school
settings by Binet and Simon in France at the dawn of the twentieth century.
This test assessed skills expected of school children of different ages. Its
purpose was to serve as an objective criterion for sifting out children considered
retarded (to be placed in special classes) and for placing other children at
their appropriate grade level (see historical background in Fancher, 1985). Binet's test items were later extended
for use with adults.
Today, the items of adult IQ tests still
remain pervasively based on school-related skills. The test taker and the test
administrator usually follow roles analogous to those of a school teacher and a
pupil at exams. These roles encompass various implicit requirements specific to
Western culture, as noted below.
In this chapter, I discuss underlying
conceptual and methodological issues in contemporary research on human
intelligence. A major obstacle in intelligence research is the use of inadequate measurement tools. Another
obstacle is the frequently encountered static view of intelligence as
biologically transmitted via genes and relatively
immutable (unchangeable) during the lifetime. Many psychologists also treat
intelligence as a unidimensional phenomenon,
reducible to a single IQ measure. This unidimensional approach fails to
adequately explore creativity, one of the most vital aspects of intelligence.
Contemporary fashionable "academic" trends such as J. Philippe
Rushton's and Richard Lynn's reports on genetically based "racial
differences" in intelligence are often based on an archaic or incompetent methodology. Those who
follow these trends will miss the opportunity to more fully use the human
potential for economic and emotional benefit of all involved.
The
intelligence test interpreter typically assumes that the test taker is
motivated to make the best possible effort. However, this motivation to succeed
and excel may be relatively weak or even absent in some segments of our
society. In addition, test items traditionally are imbued rather exclusively
with the mainstream culture of the country where the test was developed. In
some cases, intelligence tests measure the extent to which the individual is
familiar with that particular cultural tradition rather than the test taker's
cognitive talents per se. For
instance, questions such as "Who was the American president during the
Second World War?" have limited validity for assessing intelligence
outside North American mainstream culture. Items assessing arithmetic skills or
rote memory (memorising series of digits comparable to telephone or fax numbers
or postal codes) may also be less relevant in cultures where numeric coding is
less pervasive.
Some psychologists misinterpret tests such
as the Raven's Progressive Matrices as measures of fluid intelligence,
relatively independent of formal schooling. Yet the Raven's Matrices obviously
contain items that can be solved more easily by persons trained in geometry or
in algebraic formulae involving negative and positive numbers. These tests are
of dubious value if administered to persons raised within a dramatically
dissimilar culture. The traditional Eskimo, the rural Chinese, Tibetans from
remote and relatively inaccessible villages, disadvantaged South African
blacks, or US blacks and Latinos isolated in a ghetto would likely perform
better on items whose content is more consistent with their well rehearsed
normal daily activities.
Multiple subcultural discrepancies between
the test taker and the test developer or test interpreter often prevent IQ
scores from adequately reflecting human intellectual potential. Some of these
discrepancies were extensively discussed by Dalton Miller-Jones (1989).
Noteworthy is the particular use of language in specific sociocultural
environments. For example, in response to the item "What is a hat?,"
the child raised in a poverty stricken ghetto subculture may reply with
action-related elementary words such as "you put it on your head."
This response is more adaptive in the particular subculture than a dictionary or
encyclopedia style definition expected by IQ tests. The dictionary style
response could lead to misunderstandings or provoke the disapproval of
significant others.
Classical textbooks of psychological
testing have warned that "it is unlikely that any test can equally be fair
to more than one cultural group” (Anastasi, 1988: 357). Numerous academic
psychologists still misinterpret IQ scores from other cultures as indicating
genetic inferiority of these groups. For example, Richard Lynn extensively
relies, in his postulate of racial inferiority of blacks, on tests such as the
Raven's Matrices used in African settings (see critique by Leo Kamin, 1995).
Those who defend Lynn's position may argue that blacks are in poverty stricken
ghettos because of their genetically inferior intelligence and that their
lifestyle and economic condition are a consequence of inborn intellectual
inferiority.
This
circular reasoning ignores the value of high-quality formal schooling or the
impact of conveniences available rather exclusively for the upper socioeconomic
class, such as CD-ROM equipped computers or frequent travel to other countries.
These misinterpretations of scores on IQ
tests have a long history. Some of the psychologists involved in assessing
immigrants on their arrival to the United States in the first half of this
century interpreted low test scores as a sign of feeble-mindedness The
prominent psychologist Henry Goddard reported extremely high rates of mental
retardation for several immigrant groups (Jews, Italians, and Russians) and
concluded that "One can hardly escape the conviction that the intelligence
of the average third class immigrant is low, perhaps of the moron grade"
(1917: 243). Similar misleading claims typically have been associated with a
reliance on poor methods and blatantly nonrepresentative samples. For example,
Goddard himself admitted that his data were only from six small highly selected
groups. Many of these immigrants were not sufficiently familiar with English or
psychological tests to comprehend what was happening during the assessments.
Psychologists naively considered non-verbal instructions for these IQ tests as
adequate, on the untested assumption that non-verbal communication does not
differ from culture to culture.
IQ
Scores as Indicators of Criminality?
As
mentioned by Evans and Waites (1981), American psychologists often
misinterpreted IQ scores as an indicator of criminal potential. According to
Terman, "all feeble-minded are at least potential criminals. That every
feeble-minded woman is a potential prostitute would be hardly disputed by any
one. Moral judgement, like business judgement, social judgement, or any other
kind of higher thought process, is a function of intelligence" (1919: 11).
Goddard's (1917) article on feeble-mindedness among non-Anglo-Saxon immigrants
to the United States may have contributed to the subsequent application of very
restrictive immigration quotas. Countless refugees and dissidents in German
Nazi or Soviet dominated territory perished during World War II and the postwar
decades as a result of these quotas.
Heritability
of IQ Scores?
Both
genetic factors and environmental factors may determine the level, style, and
content of adult intellectual functioning. The environmental influences include
both psychosocial influences (such as parental stimulation, formal education,
peer pressure) and biological influences (such as nutrition, climate, bacteria,
and environmental toxins). There have been numerous attempts to determine the
relative contribution of the genetic and environmental factors. Despite these
efforts, no scientist has succeeded so far in offering a generally accepted
theoretical solution for determining the extent of heritability of
intelligence. Published estimates of its heritability vary between the
statistically feasible extremes. However, the underlying procedures are based
on false premises and dubious statistical methodology (see Crusio, 1990;
Roubertoux and Capron, 1990a; 1990b; Schonemann, 1989; 1990; 1992; 1995;
Taylor, 1980). The case of the British psychologist Sir Cyril Burt is
instructive.
During and after World War II, Burt was
revered as an authority on the question of heritability of intelligence.
Favouring hereditary over environmental explanations, he supported his opinion with
data from studies comparing IQ score similarity of monozygotic (i.e.,
identical) twins with their genetically less closely related siblings. Burt's
particular merit seemingly consisted in gathering the largest set of data on
identical twins who were raised separately. According to Burt, these twins were
separated in early childhood and raised in different socioeconomic
environments. His data, if credible, would have helped to tentatively explore
the relative contribution of environments and of genes to adult human
intelligence (for historical background, see Fancher, 1985; Hearnshaw, 1979).
Burt's methodology was generously and
uncritically praised by several politically influential figures within academic
psychology such as Hans Eysenck and Arthur Jensen. After Burt's death, however,
closer scrutiny of his work by Leon Kamin (1974; 1981) suggested carelessness
and fraud. For instance, Burt was so negligent in his research reports that he
even failed to indicate which intelligence tests he used to measure
intelligence. Burt also published his papers with co-authors ("Miss
Conway") who could never be located. These "co-authors" were
totally unknown in the institution listed as their place of employment. They
were also unknown to members of the scientific community of that time. They
were probably invented by Burt to render his research claims more plausible.
Burt also reported findings of almost
identical (and in some cases identical) correlation coefficients for twin
samples of gradually increasing size. Since IQ tests are not a precise tool, it
is unlikely that an identical IQ will be obtained even when retesting the same
person over time. The likelihood of repeatedly obtaining the same or almost
identical coefficients while increasing the sample size in Burt's studies is
extremely small. Burt also reported that the socioeconomic status of the
adoptive households for the twin pairs (supposedly rated by Burt on a six-point
scale) was uncorrelated. This would indicate that the twins were distributed
rather randomly to families from various socioeconomic strata. This is a
methodologically improbable situation: under normal circumstances, separated
twins are likely to be placed into at least partly comparable adoptive
environments. These methodologically and statistically suspect aspects of
Burt's data (see more details in Kamin, 1974; 1981) as well as Burt's
reluctance to let other researchers inspect his raw data strongly suggest an
uncomfortable conclusion: Burt may have fraudulently manufactured the data to
support his belief that intelligence is largely inherited.
Burt's charismatic impact on British social policies
adversely affected millions of children in the United Kingdom. According to
Fancher, Burt “testified to British government committees that children's
intelligence levels were largely fixed by the age of eleven or so, and were
accurately measurable by standard tests given at that age. Thus Burt's was one
of several influential voices which helped produce the so-called "eleven
plus" examination system in Britain, under which all eleven-year-olds were
given a series of academic and intelligence tests, the results of which
streamed the top-scoring minority into intellectually demanding "grammar
schools" and the majority into the less challenging "modern
schools." It was virtually impossible for a child to move from a modern to
a grammar school, and grammar school training was required for eventual
acceptance into a university.” (1985: 176)
Ironically,
Burt was promoted to prominent positions within British academic psychology,
including chair at the University College of London. As editor of the British Journal of Statistical Psychology, he
was able to fill the journal with his own numerous articles, some of which were
extremely lengthy and had not the remotest connection with statistical or any
other branch of mathematical psychology (Hearnshaw, 1979). His various academic
and editorial positions provided him with ample opportunities to selectively
promote students with similar hereditarian views: if he were likely to select
and promote his protégés on the basis of their personal political views rather
than on the basis of their methodological skills, we now may have an aging
generation of academic psychologists artificially promoted by his charismatic
influence as well as subsequent generations of those similarly promoted by
Burt's former protégés. These underlying phenomena could partly explain the
contemporary boom of sociobiological or behavior genetics publications in which
"heritabilities" are calculated for a wide range of behaviors on the
basis of dubious statistical models and unrealistic methodological assumptions
(see criticisms presented by Crusio, 1990; Flynn, 1987a; Roubertoux and Capron,
1990a; 1990b; Schonemann, 1989; 1990; 1992; 1995; Taylor, 1980; Wahlsten,
1994).
Thomas Bouchard has been represented by
journalists in the last decades as one of the most prominent investigators into
heritability of behavior and intelligence. However, both his hereditarian views
and his reluctance to submit his twin data from heritability studies to an
independent inspection by peer scientists (see Horgan, 1993) are largely
reminiscent of Cyril Burt. Without peer scrutiny, research data have very
little scientific value.
Environmental
Influences
It
is important to emphasize that the static concept of intelligence as primarily
genetic in origin conflicts with evidence of a massive increase in IQ scores
from one generation to the next. According to Flynn (1987b), data from fourteen
economically advanced nations indicate IQ gains ranging from five to
twenty-five points in a single generation. This intergenerational increase
suggests there are powerful environmental influences that affect performance on
tasks typically included in IQ tests. This increase is frequently ignored both
by authors of contemporary introductory psychology textbooks and by researchers
who study human intellectual potential.
There are other examples of environmental
factors in IQ differences. For example, low brain weight found in some old data
on blacks from hot African countries could be related to relative infant
malnutrition rather than to genetic racial differences. The detrimental impact
of malnutrition on brain development has been documented by Monckeberg (1973).
Malnutrition affects not only brain and head size but also intelligence. For
instance, the quality and quantity of nutritional intake in 153 Egyptian
infants aged between eighteen and thirty months was found to be correlated with
their intellectual performance at twenty-four months: infants with more
adequate nutrition fared better Wachs et al., 1993). Recent studies on adults
suggest that even skipping breakfast may result in relatively inferior
performance on subsequent cognitive tasks such as those from Cattel's Culture
Fair test (Spring et al., 1992).
At
present, black parents tend to be younger than white parents at the birth of
their first child. Black parents also more frequently have larger families,
thus having more later-born children. Statistical reviews by Storfer (1990)
show that, on average, children of younger parents have lower IQs than those of
older parents and that later-born children from large families have lower IQs
than those born first. According to Storfer, these and related factors could
explain a large part of IQ discrepancies reported in some comparisons of black
and white children.
Unidimensional View of Intelligence
Measuring
intelligence in IQ points is reductionistic
in the sense that it reduces an individual's intellectual ability to a single
number. This is a common practice in clinical, industrial, and school settings.
The underlying assumption is that all (or most) facets of intelligence have the
same underlying common factor, often labelled "g". The g factor
theory has generated lengthy academic debates.
According
to Schonemann (1995), the belief in a unitary g factor is irreconcilable with
modern statistical methodology. Contemporary mainstream research has not
adequately mapped human intelligence. As noted above, this research has mostly
been restricted to school-related numerical, verbal, and spatial skills and to
the culture-specific information disseminated in public and private schools.
To the extent that these tasks require similar skills, reductionist
psychologists may find illusory support for the unitary g factor theory, at
least in some studies. Traditional IQ tests tend to be the epitome of the
school routine. Test takers and test interpreters implicitly share the beliefs
that there is only one correct solution for most items (as in convergent
thinking), that all viable solutions are known to the test psychologist, and
that these correct solutions are only reiterated by the test taker. The
reductionist approach fails to include items assessing creativity (as in
divergent thinking; see discussion in Cohen et al., 1992). These creative
aspects of intelligence are crucial for scientific and economic progress, human
adaptability, and the long-term survival of our species.
Greatly stimulating for pioneers exploring
neglected aspects of human intelligence is the intuitive monograph by Howard
Gardner (1983). Gardner discusses seven intelligences: linguistic,
logical-mathematical, spatial, musical, bodily-kinaesthetic (as in dancers,
actors, and competitive athletes), intrapersonal (knowing oneself), and
interpersonal (knowing others). In sum, defining intelligence as whatever is
measured by IQ tests (a definition proposed by some psychologists in the past)
unduly restricts the concept of human cognitive functioning.
Reliance on Poor Research: the Examples of
Rushton and Lynn
Recent
comparisons of intelligence in different racial groups by J. Philippe Rushton
(University of Western Ontario, Canada) and Richard Lynn (University of Ulster,
Northern Ireland) are remarkable examples of pseudobiological focus (see Lynn,
1993; Rushton, 1988). Unfortunately, their research has had more influence than
its quality deserves. In this section I summarise methodological objections to
their conclusions about human intelligence.
Head
Size Measures as Indicator of Intelligence
Both
Rushton and Lynn use head size measures as a convenient substitute for IQ
scores, on the inaccurate assumption that these two variables are sufficiently
closely related. Rushton (1990a) listed correlation coefficients from twenty
studies of head size and intelligence to document the existence of a
statistical relationship between the two. The average correlation in Rushton's
list (as calculated by Cernovsky, 1991) was only 0.18. This is too low to
support Rushton's and Lynn's interpretation of head size differences as
differences in intelligence. Classical introductory psychology textbooks warn
about similar overinterpretations of low correlation coefficients. For
instance, Atkinson et al. state: "Correlations between 0 and .20 must be
judged with caution and are only minimally useful in making predictions. One
should be suspicious of investigators who make strong claims that are based on
correlation coefficients in this lower range" (1983: 24).
As reported in more detail elsewhere
(Cernovsky, 1994), Bouchard defended Rushton's reliance on low correlation
coefficients. He argued during the question period following Cernovsky's (1992)
paper at the International Congress of Psychology in 1992 that weak correlation
coefficients should not be underestimated. As support, he referred to
Rosenthal's recent work on this issue. But this is a misuse of Rosenthal's work
on meta-analysis.
Rosenthal and Rubin (1985) argued that
small statistical trends are frequently invaluable even when they fail to reach
traditional criteria of statistical significance (p = 0.05 or 0.01). They
provide the following example:
“Suppose that, of 20 critically ill patients in a
small, randomised experiment, 10 are assigned to a treatment condition and the
other 10 are assigned to a control condition. If none of the control patients
survive and 3 experimental patients survive, our results will not be
significant at p < .05 by a chi-square test or a Fisher exact test. However,
we believe it is essential on scientific as well as ethical grounds that such
results should be published.” (1985: 528)
In
Rosenthal's example, Type I error (use of an ineffective drug to treat a
patient who is going to die very soon anyway) has only minor negative
consequences compared to Type II error (failure to use treatment that might
save 30% of the critically ill patients). The majority of us, if critically
ill, would still opt to receive the treatment. That is, we would choose a
slight chance of survival even if it is not a "statistically
significant" chance, because without the treatment we would die anyway.
There are no negative consequences from taking the drug unnecessarily.
This is not at all comparable to claiming,
based on weak correlations, that head size is an indicator of intelligence.
Type I error, underlying Rushton's speculations, leads not to minor negative
consequences but to the defamation of blacks, promotion of racial hatred, and
even unnecessary loss of life in racist mob activities. Rosenthal and Rubin
defend an experimental use of weak trends in situations where ignoring these
trends may result in clearly aversive consequences. But Rushton and Lynn go far
beyond this statistical context: they treat two weakly correlated variables as
sufficiently identical to rely on the first as the indicator of the second.
Rushton and Lynn also occasionally refer to
modern brain size studies. The relationship of brain size to IQ score may be
somewhat closer than that found for head size. However, this relationship is
also too low to justify substituting one variable for the other. For example,
the correlations found by Andreasen et al. (1993) ranged from 0.26 to 0.56,
indicating from 12% to 31% of shared variance. Yet, Andreasen and her
colleagues emphasized the modest nature of these relationships. Even 31% of
shared variance certainly does not justify using one variable as a viable
measure of the other. Rushton and Lynn also ignore clinical case studies by
Lorber on British adolescents with an extremely small cortex (see summaries in
Lewin, 1980). Some of them had IQ scores at or above 120 and were academically
successful in high school and subsequently at university, including in areas
such as mathematics.
Obsolete
Data Sets
Rushton
(1988; 1995) and Lynn (1993) frequently rely on antiquated data. As pointed out
by Weizmann et al. (1991), old skull collections may have peculiar social
histories. For example, both Rushton and Lynn marshalled the skull size data
from the famous Morton's collection as evidence of racial inferiority of
blacks. Yet the skulls from Morton's collection were originally collected by
George Glidden (Stanton, 1965), a
supporter of slavery. Glidden may have pre-selected the skulls for each racial
group on the basis of skull size in order to support his political position.
His motivation was to prove that the creators of ancient Egyptian civilization
were white and that blacks existed only in subservient positions.
Misrepresentation
of Conclusions of Other Scientists
Both
Rushton (1990a; 1990b; 1990c; 1991; 1995) and Lynn (1993) misrepresented
statistical analyses by Beals et al. (1984) as supportive of their racial
theory. According to Rushton,
“Beals et al. (1984, p.306, Table 2) computerised the
entire world database of 20,000 crania gathered by 1940 (after which data
collection virtually ceased because of its presumed association with racial
prejudice), grouped them by continental area, and found statistically
significant differences. Sex-combined brain cases from Asia averaged 1380 cm3 (SD
= 83), Europe averaged 1362 cm3 (SD = 35), and
Africa averaged 1276 cm3 (SD = 84).” (1990b: 791)
The
table with cranial data averages for the continents indeed exists in Beals et
al.'s article. However, Rushton and Lynn neglected to mention that Beals et al.
explicitly warned readers, on the same page, that these data confound genetic
influences with the effects of climatic zone: "If one merely lists such
means by geographical region or race, causes of similarity by genogroup and
ecotype are hopelessly confounded" (1984: 306).
Within
a given racial group, cranial capacity varies depending on the climatic zone.
For example, the American Indians are spread over a wide variety of climatic
zones and show a corresponding variation in skull size: those from warmer
climates have smaller cranial capacity. This pattern is also true for other
racial groups. Beals et al. concluded, on the basis of extensive statistical
analyses, that correlations of brain size to race are spurious: smaller crania
are found in warmer climates, irrespective of race. In fact, Rushton's own
tabular summaries of cranial data, based on Herskovits (1930), clearly show
these trends. In Rushton's summaries (1990b: see Table 2), the average cranial
capacity for North American blacks (1622 cm3) is similar to the
average for Caucasians (1621 cm3) from comparable climatic zones.
Caucasians from warmer zones such as Cairo (1502 cm3) were similar
to some of the black Africans, for example, the Masai (1508 cm3). It
is only by "pooling" the black North American data with data for
blacks from countries within hot climatic zones (notorious for famine and
infant malnutrition that impede brain growth) that Rushton obtained an illusory
support for his "genetic" postulates.
Rushton
(1988; 1995) also misleads his readers to assume that Tobias's (1970) survey of
cranial data supports his theory. Rushton selectively reported only those data
from Tobias's monograph that were consistent with his theory. He failed to
mention the data sets, also reported by Tobias, showing that cranial size and
number of "excess neurones" of North American blacks exceeded those
of the French, the English, and American whites (1970: 9, Table 3).
Another example of misrepresenting the work
of others: Lynn (1993) reanalysed old data from a study of physical
characteristics of Philadelphia school children in the decades preceding 1970,
collected by Krogman (1970). He concluded that head sizes are larger in whites
than in blacks and also larger in men than in women. According to Lynn, given
the positive association between brain size and intelligence, "there
should be corresponding race and sex differences in intelligence" (1993:
92). But Lynn misled his readers with respect to the social background of the
children in Krogman's study. Allegedly quoting directly from page 4 of
Krogman's monograph, Lynn described the blacks as being from the middle and
upper-middle class and the white children as being from the middle class.
However, on that page Krogman (1970) described the sample of black children as
being from the lower-middle and middle-middle class and the white children as
being from the middle-middle and upper-middle class. The two racial groups
differed with respect to socioeconomic class in the opposite direction than
sketched by Lynn. According to Krogman, the whites were largely from the white
collar and skilled labour population with a few from a professional and
academic level. The blacks were from the blue collar and semi-skilled labour
population. Since the data were collected in the decades preceding 1970, these
class differences in urban settings could well be associated with a major
difference in quality of child health care, nutrition, educational stimulation
by parents, and other factors with a potentially adverse impact on the central
nervous system and intellectual development.
Several types of brain size measures can be
used when comparing samples grouped on the basis of gender or skin colour. Some
researchers consider it important to correct the absolute brain size for body
height, weight, or surface, on the assumption that larger bodies require
proportionately larger brains for the control of various motor and physical
functions. Rushton's and Lynn's uncritical interpretation of these measures of
brain/body size ratio as a valid indicator of biological intelligence is
misleading: some lower animals such as squirrel monkeys or house mice have more
favourable brain/body ratios than humans without demonstrating a corresponding
intellectual superiority (see a review of Rushton's theory by Cain and
Vanderwolf 1990). Both Rushton and Lynn almost always rely only on absolute
brain (or cranial) size data. Significantly, they resort to corrections of
cranial size data for body size only when convenient to defend their dogma of
black inferiority. For example, Lynn (1993) built almost his entire article
(and his thesis of blacks' intellectual inferiority) exclusively on the review
of absolute cranial size data. Yet he then suddenly switched to the cranial
size "corrected" for body height when the absolute cranial capacity
in black girls was greater than in white girls.
Meta-Analysis
of Rushton 's Data by Gorey and Cryns
A
recent meta-analytic study provides additional evidence of methodological
weakness in Rushton's procedures. Gorey and Cryns (1995) indicated that the
mean correlation coefficient in data sets listed by Rushton for black-white
intelligence differences was only 0.23. Gorey and Cryns also found that
Rushton's work has an unbalanced overrepresentation of references to supportive
data. When they recalculated the data for the same variables based on a
computerised random literature search, the mean correlation coefficient dropped
to 0.15. Similarly, the mean coefficient based on data sets chosen by Rushton
to document black-white differences in personality and temperament was 0.37.
But with data based on a random literature search, this coefficient dropped to
-0.02. Gorey and Cryns examined eight variables. On all eight, Rushton's
"data" were more supportive of his hypotheses than the data based on
a computerised random literature search.
Preferential
Publication of Supportive Data
Some
researchers (and also journal editors) may hesitate to publish data not
supportive of their personal beliefs. Or, while gathering the data, their data
can somehow be distorted to match personal expectations. For instance,
Rosenthal's (1991) statistical work suggested that about two-thirds of
observational errors made by investigators are in the direction of supporting
their hypothesis. These biased errors occasionally push a result over the magic
0.05 cliff, leading to "statistically significant" confirmatory
findings.
In some cases, political bias or political
pressure may lead to a preponderance of published findings that are
unfavourable to blacks. For example, the editor of Canadian Psychology, the leading Canadian psychological journal,
published a lengthy article by Rushton defending his racial research and
expounding his racial theory. Subsequently, the editor declined to publish a
manuscript describing methodological and statistical deficiencies in Rushton's
work. He said that "each new salvo against Dr. Rushton's position
inevitably requires that he be permitted the right of response, and his views -
which do not seem to change - are trotted out again and again" (letter
from Patrick O'Neill, editor, Canadian
Psychology, June 20, 1991). The editor's letter admitted that the submitted
criticism of Rushton may present original methodological information. Yet,
these methodological considerations were less relevant for the editorial
decision than "academic politics" in Canadian circles.
Until
recently, black students were systematically prevented (often by the brutality
of the white mob) from entering US universities. Some who persisted paid for
this with their lives. For this reason, most data are from studies prepared by
white psychologists only, some of whom are notorious for their bias against
blacks. Their biased research style is exemplified by Arthur Jensen's work. His
findings of racial differences in reaction time to complex tasks (interpreted
as a relatively culture-free measure of intellectual functioning) have been
artificially manufactured by his selective publishing of confirmatory results
only. He has failed to publish his own disconfirmatory data (see documentation
by Kamin and Grant-Henry, 1987).
Conclusion
The
critical psychologist may deal with a wide variety of topics in intelligence
research. The issues raised here partly overlap those discussed by Kamin (1995)
in his critique of the highly publicised controversial book The Bell Curve (Herrnstein and Murray,
1994). Herrnstein and Murray erroneously treat Lynn's and Rushton's work as a
reliable scientific source. They fail to discuss the numerous methodological
flaws in Rushton's and Lynn's methodology as known from various reviews (Cain
and Vanderwolf, 1990; Flynn, 1989; 1990; Kamin, 1995; Weizmann et al., 1990;
1991; Zuckerman and Brody, 1988).
The widespread promotion of the works of
Rushton and Lynn and recent attempts to rescue the scientific reputation of
Cyril Burt (see Jensen, 1992) are alarming academic developments. These trends
may discredit American and Canadian academic psychology on an international
scale. Research funding could be channelled more constructively into more methodologically
adequate research on personality factors and on strategies that enhance
economic or scientific creativity and productivity.
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