The
Further Mismeasure: The Curious Use of Racial Categorizations in the
Interpretation of Hair Analyses
Tom Mieczkowski,
Ph.D.
The University of South Florida
Department of Criminology
“Racially, I
seem to have (who knows for sure) seven blood mixtures: French, Dutch, Welsh,
Negro, German, Jewish, and Indian. Because of these my position in America has
been a curious one. I have lived equally amid two race groups. Now white, now
colored. From my own point of view I am naturally and inevitably an American. I
have strived for a spiritual fusion
Jean Toomer, 1922
Introduction
It has been noted that some academics in the traditional physical
sciences (e.g., chemistry, physics) have disparaged the social sciences for
their lack of many of the features associated with a "mature"
discipline. Those features consist mainly of:
·
A relatively
unified theoretical base
·
A widely
accepted inquiry method and measurement system
·
A strong
tradition of intensive experimental work
·
The
development of unambiguous empirical indicators which underlie their major
constructs
I acknowledge that
there is a debate about the nature of scientific method, and there is
considerable argument over the correct "paradigm" that drives
physical science (e.g., Kuhn versus Popper, etc.). However, it is generally
true that social sciences are seen as "soft" or "fuzzy" (or
even worse!) by many in the "hard science" community. It is also
generally true that many social scientists are self-conscious about the degree
to which they are "real scientists" in comparison to their "hard
science" colleagues. Indeed, a recent example can be seen in the
publicized poke in the eye that a physicist gave to "soft science" by
writing a wholly fabricated and nonsensical article on
"deconstruction" and getting it accepted in a peer-reviewed journal.
Even within the social sciences those who are more quantitative in their work
often seek to distance themselves from qualitative researchers. Few in the
social sciences easily tread in both domains.
However, one can raise a substantial criticism of the traditional
sciences and these often thinly disguised feelings of superior intellectual
rigor (and I do acknowledging their clear and enviable record of useful and
demonstrable products). The expertise one may have in a domain such as
chemistry, engineering, physics, or optics does not translate into an
"automatic" expertise in the "soft sciences". In fact, it may be that the "hard
edges" of these sciences either dull the capacity to deal with "fuzzy
systems" or desensitize the perception to the problems of ambiguity in
analyzing problems.
In effect, does the
perception that a failure in a discipline to attain the dominant consensus and
product attributes associated with physical sciences entitle one to assume
there is really no "genuine" basis to disciplines and their
associated methods whose outcomes generate controversy, dissent, contradictory
but logically consistent explanans,
etc.? Does it also lead to a belief that "expertise" in such areas is
attained with little or perhaps no intellectual effort in disciplines that seem
to have (in the eye of the beholder) little or no substantive content? And can
such attitudes themselves be dangerous, producing myopic, naïve, and even
nonsensical ideas about the world?
There are multitudes of sub-problems that stem from contemplating this
fundamental question. It is the modest ambition of this paper to identify and
discuss some recent experiences in the assumption of what one might call
"common sense" or "assumed" perspectives on a complex
sociological and anthropological issue, that of race and racial identity. These
events demonstrate dramatically erroneous conceptualizations about the
"real world". In this case, I suggest that the simplistic treatment
of a "soft science" construct (race) incorporated into a "hard
science" context resulted in wildly inaccurate and even absurd conceptualizations
and conclusions. The moral I try to draw from this description is that the
experience demonstrates that there are dangers and costs associated with a
failure to be sensitive to the subtleties and importance of data produced by
social science and anthropological science. And there are dangers in not being
reflective, historically informed, and situated to consider what I might
characterize as a long view of even "simple variables" in any
analytic endeavor.
"Race Bias" in a Technical
Measure: The Controversy with Hair Analysis
Synposis
The evolution of the idea that hair
analysis for detection of xenobiotics, and for criminological purposes, for
illegal drugs and toxins is a complex one, and is treated at some length in a
variety of publications (Kintz 1996: Mieczkowski 1992). I can only give a brief synopsis of it here, and I refer the
reader to the bibliography for a more in depth consideration of this topic and
its history.
As many are aware, in the early
1950's it was proven possible to recover psychoactive substances from hair.
Since the 1970's this capacity has been intensively explored and developed,
largely in response to the general rise in interest and utilization of chemical
analysis for illicit drug detection. This intensification of development was
undoubtedly an outcome of the increasingly militant "war on drugs"
climate that permeated most official policy on drug control. Concomitant with
this was an increasing interest by the private sector to identify drug users in
the workplace, the criminal justice and correctional system to identify drug
users in various settings, and the military to identify and exclude drug users
from service.
Hair analysis has been of interest
for primarily two reasons: it permits a long-term retrospection of drug use far
beyond either blood or urine-based analysis, and it permits a relative
quantitation of the degree or intensity of drug use. Of these two attributes,
the first (retrospection) is generally accepted without much controversy, while
the second (quantitation) is somewhat more contentious. However, for our
purposes here, we will not dwell on these aspects of the technology. Suffice it
to say that on a worldwide basis the efficacy of hair analysis is well
accepted, and almost without exception the American judicial system has
sustained the legality of hair analysis as a legitimate forensic technique.
Indeed, millions of hair analyses for illegal drugs are done annually in the
United States. The technology is used worldwide, and is likely to remain in
place as a permanent part of the drug-screening and drug-monitoring repertoire.
The Race Bias Controversy
The basis of this controversy is
easy to apprehend. It is argued, quite simply, that hair analysis performed by
identical test protocols produces systematic differential outcomes in persons
of different races. These systematic outcomes are labeled as a "racial
bias" in the hair analysis procedure. These differences are alleged to be
such that the test is biased against
African Americans and by implication biased toward
"Caucasians". "Biased" as used in this context means that
the test will produce a positive result in one race (African-American")
while under identical conditions it produces a negative result in the
contrasted race ("Caucasians"). The controversy centers on a couple
of critical concepts, the concept of “race” and the basis upon which races are
identified and racial identities assigned, and the concept of “bias” as it is
applied to the outcome of a bioassay. The race bias issue has entered into the
"folk idiom" of drug testing. It is increasingly raised as a defense
against a positive assay interpretation whenever hair analysis is under some
review or consideration.
The first person to raise the race bias issue in print was a toxicologist,
Robert Bost (Bost 1993). Bost himself did not do and has not published any
original work on hair analysis that led to his suggestion that hair analysis
may be racially biased. Rather, in a generalized review of hair analysis, he
asked the question "are there any racial differences which might affect
the deposition and retention of drugs in hair?" Bost did not define
"race" or indicate how one establishes "racial identity" or
in what ways hair would be associated with race, although clearly he intends to
mean a biological conceptualization as opposed to a sociological one.
Interestingly, Bost did not present data using any traditional anthropological
descriptor of race (e.g., Caucasian, Negroid, etc.). Rather, Bost presented
data mainly descriptive of ethnic categories (French, German, Irish, Polish,
etc.). He includes “African” and “African-American” as the only groupings that
under current Federal guidelines would be identified as a racial group.
After his rhetorical question "are there any racial differences"
he presented a series of gel electrophoresis slides done by another person
(J.K. Dzandu: Dzandu was not a co-author on Bost's FSI article). As noted, Bost
(and presumably he is using Dzandu's typology) presents categorical divisions
that are ethnic groups. The categories are:
Dzandu's data, as
presented by Bost, shows photographs of a series of gel electrophoresis plates
for a variety of "racial/ethnic" groups. The relationship between
this mix of race and ethnic descriptors and the physical nature of hair is
unexplained by Bost, and in the cases of mixed racial and ethnic descriptors
there is no discussion of the relative "contributions" of each of
these discrete types to hair morphology.
The meaning of Bost's "ethnic/racial" categories does not
appear to be based on any systematic or taxonomic idea of race. It is also
interesting to note what is absent from the list, as well. If there is a
"German" or "Mexican" keratin, why is there no
"American" keratin category? Are African-Americans and Africans able
to be treated as dichotomous racial groups? Considering Bost's
conceptualization of race, the more one contemplates his categories, the odder
they seem to be. For example, there is a "Mexican/German" category.
Can't one be both "Mexican" and "German" at the same time?
What aspect of the hair protein is "Mexican" and which aspect is
"German"? Bost, in a pattern frequently repeated by others, uses
interchangeably the terms “race” and “ethnicity” without consideration that one
can possess both race and ethnicity at the same time. Curiously, Bost reports
that Dzandu's conclusion was that "the keratin patterns of individuals
belonging to different ethnic/racial groups are generally
indistinguishable". What then leads Bost to state "the fact that
there are some differences in some hair proteins should make us pause to
consider whether there are ethnic differences that are significant factors in
drug incorporation into hair"? This seems to contradict Dzandu's own
statement of these racial types being "indistinguishable".
Unfortunately, Bost's writings on
race are typical of the controversy on hair analysis. This very poor level of
discernment on the complexities and problems confronting the issue of
"race" has characterized the controversy on "race bias" in
hair analysis. The social sciences, in this regard, have a much more
sophisticated level of understanding of these complexities, and have generally
reflected this in the published literature. Medical researchers, who span the
domain of sociological, psychological, and biological variables, have also
recognized the profound complexities of relying on "race" variables
in the analysis of bio-phenomenon. Hahn (1992), for example, examined the
accuracy of four basic assumptions on race ethnicity that underlie health
statistics and their analysis. These included the assumptions that categories
of race and ethnicity are consistently defined and ascertained in data
collection, that race and ethnic categories are understood by those who are in
these target populations, that participation, response, and enumeration
characteristics are high and similar across race/ethnic categories, and that
individual responses to race and ethnic identity are consistent over time and
across different measurement instruments. In all four cases Hahn found that there
are serious problems underlying each of these assumptions, and characterizes
the collection of race and ethnicity data "problematic" in the health
and epidemiological sciences. Similar to Hahn's concerns, Osborne and Feit
(1992) noted that "when race is
used as a variable in research there is a tendency to assume that the results
obtained are a manifestation of the biology of racial differences . . .
researchers, without saying so, lead readers to assume that certain racial
groups have a special predisposition, risk, or susceptibility" to the
problem studied. Zuckerman (1990) in examining racial differences in research
in social and psychological domains called the examination of group differences
based on racial categorization "questionable" and said the
explanation of such differences in "strictly-biological-evolutionary"
terms even more dubious".
Fairchild (1991) in examining the use of race as a biological research
variable concluded "sociobiological models of 'racial' differences
promulgate a number of fatal flaws in their theoretical assumptions and
interpretation of empirical databases". Yee and his colleagues (1993) in
examining race as an analytic variable describe its use in scientific
literature as "badly muddled", and state that the conceptualizations
of race found in the research literature are "basically lay stereotypes
that do not go beyond self-identification. Such definitions ignore
heterogeneity, assume unproven race-behavior causal relationships, confuse race
with intervening factors of bias (including inter-rater bias), ethnicity,
social class, and culture, and have not been sanctioned by scientific and
professional consensus."
The unreflective and unspecified use
of racial and ethnic categorizations in the case of interpretation of hair
analyses serves as a further example of the "badly muddled" method of
data analysis and interpretation which permeates this literature. It is well
beyond the scope of this paper to deal with every aspect of this issue, but I
want to provide a few case examples that characterize the work purporting to
show that this assay method is “racially biased”.
Furthering Race Analysis: The Work of
Kidwell and Blank, and Henderson and Harkey
Kidwell and Blank's
Work on Race and Hair Type
The first group to raise the issue
of possible racial bias based on their own research work were Kidwell and Blank
(1990-96). They reported findings in the early 1990’s on the cocaine recovery
from ten hair samples (four black hair and six brown) analyzed in their
laboratory. The dark hair showed a higher concentration of cocaine. The
Kidwell/Blank team applied the term “hair types”, which were de facto the color of the hair. The
transition from hair color to hair types might seem trivial or inconsequential
at first glance. But, on reflection, it is critical to ask what are the
typologies that are implied in this? The major implication associated with this
is that hair color is a racial phenotype, and as a consequence hair analysis is
“racially biased”. In fact when challenged about his implications of hair
analysis as racially biased, Kidwell denied that such an implication was his
intent at all. He stated that in reference to his own data “in any case, these
results should NOT (emphasis original) be interpreted to imply a racial bias
against hair analysis but only that a correction factor or different cut-off
levels may be needed for different hair types.”
By 1996 Kidwell began to routinely use the term "hair type" in
papers and presentations, although no definition or protocol was ever presented
to establish how a "hair type" is identified and assigned to any hair
specimen, except to note its color by observation. Indeed, in a frank admission
of this in a 1996 article Kidwell states in presenting his data that "hair
type is not a well defined term. However, it reflects hair color, hair history,
race, and ethnicity of its donor".
So, race becomes overtly introduced into hair “type" and by 1996
Kidwell was routinely using race and ethnic categories in his data
presentations. And the basis for categorizing “hair types” was largely
unspecified. The protocol for categorization was never presented. It primarily
appeared to be hair color, although Kidwell emphasized and de-emphasized color
in various papers and presentations. For example, in virtually all data he
presented he listed three attributes: hair color, race/ethnicity, and cosmetic
treatment he has labeled "permed".
He included various and sundry ethnic and racial categories as well, although
the specific ethnic groups varied to some degree over time. In spite of his
general expressions about "bias", however, he also recognized that
outcomes for his experiments did not support the typology. Kidwell stated in
1996, for example, that in response to prolonged soaking of hair in a solution
of cocaine:
"black African hair incorporated more
cocaine than other hair types, perhaps indicative of prior hair history.
However, variables other than color must be considered, as among the Caucasian
hair types blond hair incorporated similar amounts of cocaine and morphine
compared to other more pigmented types".
The data to which
Kidwell refers is presented in Figure 1. Kidwell presented this data in 1994.
It reflects data from a hair soaking experiment (the conditions of the soaking
are in the subtitle) and utilized what have come to be the characteristic
racial and ethnic typologies associated with his analysis. He also mixed in a
number of curious and puzzling “hair types”.
Kidwell has the ethnicity, hair color, sex, and “race” all operationally
mixed together in a kind of “racial/ethnic melange”, and then each is presented
as a “hair type”.
Figure 1. Kidwell’s Hair Typologies
Comparing Uptake of Cocaine from Soaking
This is a difficult
operational measure to either comprehend or to analyze. First on a data
analytic basis, there is no apparent consistent exhaustive and exclusive
attributes which delineate categories. For example what are the distinctions
between the “Black Korean” hair type and the “Black Asian” hair type? In
Kidwell’s purview do Koreans constitute a separate “race” from “Asians”?
Consider as well the contrasted “hair types” labeled “brown Caucasian” and
“brown Romanian". Post propter hoc,
one is forced to assume from an analytic perspective that in Kidwell's racial
schema Romanians are “non-Caucasians” and thus must constitute a distinct race.
In a later article Kidwell (1995) included in his analysis “Italian hair”. In
one instance he compared six “hair types” of
“female hair”: “Korean”, “Black”, “Blonde Caucasian” “Brown Caucasian”,
“Hispanic”, and “Italian”. This data is presented in Figure 2:
Figure 2. Cocaine Binding Data Reported by Kidwell on “Female” Hair
Types
Kidwell noted that his data (Figure 2) showed that the “Korean” hair
showed a dramatically larger binding of soaked cocaine, approximately double
that of “Black” hair. “Italian hair” showed the least binding. He concludes, based on this data, that there
are race differentials in cocaine binding. The appropriate assignment of racial
differentials for binding intensity is postulated as “Asian hair > Black
hair > Caucasian hair”. It is unclear whether he means this hierarchy to
include hair irrespective of gender, or whether hair types must now reflect
gender as one of the categorical variables. We do not know whether or not sex
is necessarily a critical variable, but Figure 2 reflects only “female”
although Kidwell had not previously identified sex as important in assigning “hair
type”.
This
hierarchy delineating an “Asian to Caucasian” differential is an interesting
conclusion. Problematically, it is inconsistent with data he had reported
earlier. Consider, for example, that Kidwell reported in 1994 (see Figure 1)
that the highest concentration in his soaking experiments was attained by
“permed black African” hair (slightly more than 8 ng/mg of hair). But a second
sample of “permed black/gray African hair” attained less than ½ of that
concentration. The second highest concentration value in that experiment was
attained by “brown Caucasian” hair. This “brown Caucasian” sample attained
higher retention values than “black Asian”, “black Korean”, “black/gray African
permed” and “black Caucasian/Asian”. Gender, as we noted, in this instance was
ignored as a categorical variable.
His
second experiment, using hair collected from females, produced dramatically
different results. So what are we left to deduce? There is no discussion of how
sex by itself could affect the retention of drugs in hair, and there is no
literature that has ever claimed to identify a biological/morphological or
other marker for sex in hair. It is difficult to argue that these studies offer
compelling supportive evidence of “bias” even granting the puzzling racial and
hair “typologies” used in the analysis. Even Kidwell acknowledges that “there
is no simple hypothesis that can account for this variation in uptake”.
If
we take a large overview of this data, one must admit that nothing much can be
concluded about a race bias hypothesis based on this data. Consider that in
this method there was no effort to even test a series of groups of hair samples. One wonders if the importance of such a
step was even considered. Without such a method it is impossible to ascertain
anything whatsoever about the variability within any particular sample group or
the variability that is associated within any of the "racial
populations" to which Kidwell applied his findings. This stands out as one
of the most serious flaws in the logic of his design. The use of these
categories implies a monotonic “type” for each group. This is in direct
contradiction to virtually all writing and analysis of the last century on the
biology of race and ethnicity. And looking across the Kidwell’s own data, there
is prima facia evidence of large,
substantial variability. Consider Figure 1. We see that two “brown Caucasian”
hair samples soaked in cocaine under identical conditions exhibited approximately
a 400% difference in retention. The “blonde Caucasian” hair sample had
approximately the same magnitude of variable when contrasted to the “black
Caucasian/Asian”. Yet compared to the “black Caucasian/Asian” the “black Asian”
sample had again a 300 to 400% difference in binding. Kidwell characterized
this outcome as “some consistency by pattern”. What is the consistency to which
he alludes? And he makes this deduction without the benefit of any statistical
analysis. In the “female hair type” data (Figure 2), for example, a t test
comparing the mean values by race does not show a significant difference
(t=2.438, df = 5, p=0.06). Subjecting this same data set to a series of
nonparametric analyses also fails to show any significant pattern by race. An analysis
of Kidwell’s data from Figure 1(where sex is not specified as a variable) also
shows that there is no significant difference in comparing the cocaine
concentrations by race or color categories. A Kolmogorov-Smirnov test shows no
significance for cocaine concentration (p = .704) and a Kruskal-Wallace for
cocaine and race/ethnicity (p = .287) and cocaine and hair color (p = .540)
also fails to show any significant association. So, what is the “some
consistency by hair type” to which Kidwell alludes?
These
findings, and his own conclusion that no simple hypothesis can explain these
outcomes did not deter him from continuing to claim the data show a
“variability of drug incorporation along racial lines” (Kidwell 1996). Aside
form the failure of the data itself to support such a conclusion, on logical
grounds alone the assertion is difficult to comprehend. There is no clear
definition of what a “race” constitutes, or of what elements of the biology of
hair allow the assignment of a “hair type” to any particular sample. Indeed,
consider that it would impossible to assign a “hair type” in Kidwell’s schema
if one were to send to his laboratory a package of hair samples collected
blindly. There is no reliable way to determine race/ethnicity from a hair sample,
no way to assign it a “history” unless one talks to its associated human, no
way to assign it an ethnic character without asking its associated human. How
could a laboratory look at a specimen of hair and call it Italian? Even the
coloration assignment, when made by unaided protocol can be problematic. Can we
say there is only “brown hair”? Only “black hair”? In Kidwell’s published
figures there is no presentation of samples of “Caucasian black” hair. Why? And
consider that there has never been an attempt to determine such a simple but
critical dimension of the “typologies” as inter-rater reliability pertinent to
these categorizations. In 1999 Kidwell presented a paper which included the
following:
‘We have shown through a number of in vitro experiments that different hair
types incorporate different amounts of drugs when exposed under similar
conditions. Incorporation of cocaine tends to be correlated with race in that
the hair of African American females incorporate much more drugs than do
Caucasian males or females”.
In a National Institute of Justice Report in 1993
(Henderson, Harkey, Jones 1993), based on their controlled dose experiment with
an N of 25 subjects (4 of who are classified as “non-Caucasians: 2 African
Americans and 2 "Hispanic/Asian/East Indian" subjects), the authors
in their conclusions stated:
“Race may be the most important variable in
determining the amount of drug incorporated into hair. In fact, within the
range of doses used in our studies, race was more important than dose in
determining the level of d5-cocaine in hair. Although there were only four
non-Caucasian subjects, all four were outliers . . “
“The
outlier subjects, all non-Caucasians, could have genotype-related differences
in their drug distribution, metabolism, or elimination. However, this does not
appear to be the cause of their unusual hair analysis results . . . Although
the outliers were non-Caucasians, they were not all African Americans. Two of
the four were of mixed Hispanic, Asian, and East Indian decent (sic). The one
common feature this group did share was their coarse, dark hair . . . However,
simple differences in melanin content are an unlikely explanation for the
differences observed in our study.”
What is interesting here is that the data presented in the 1996 article
is the same data as presented in the 1993 report. The strong declaration of 1993 - that race may be the most important factor in explaining
drug concentration in hair - is
modified without any further data or new analysis than appears in the 1993
report. Why would this be so? The critical additional information appearing in
the 1996 article and not in the 1993 report is that the “non-Caucasians” are not
a single racial category (e.g., all African American, etc) but a “mixed
heritage” group of persons with both ethnic and “race” characteristics mixed
together. Of the 25 cases (itself a convenience sample with no random selection
or assignment) 4 are “non-Caucasian”. Of the four “non-Caucasians” two are
“non-African-American” (see footnote 3). The "non-African
American/non-Caucasians" are described as of “mixed Hispanic, Asian, and
East Indian decent (sic)”.
When you analyze the
data they offer including this new information the finding of a “racial bias”
effect becomes very difficult to discern. Interestingly, in the 1993 report
there is no statistical analysis of the data beyond the presentation of
findings and aggregate measures such as means and standard deviations. A closer
scrutiny of this data reveals some interesting findings:
¨
A one-way
analysis of variance and shows that the relationship between either total
cocaine recovered or mean value per segment of cocaine recovered and the
“Caucasian/non-Caucasian/African-American” trichotomy is significant (p =. 05),
but neither of these measures meets
the equality of sample variance requirement. The Levene test for equality of
variance is significant for both (it should be non-significant), indicating
that the equality of variance assumption is violated. Using a series of post-hoc
tests (Tamhane, Dunnett T3, Dunnett C, and Games Howell), permitting the
comparison of the three groups while allowing for unequal group variances,
indicates that none of the tests
attain significance at (p =. 05). Furthermore, the analysis reveals that there
are no homogeneous subsets by race designations for the three groups for either
mean cocaine value per segment or for total cocaine recovered from all
segments.
¨
The group
which accounts for the significant variance by the simple ANOVA (that is, not controlling
for the variance problems) is not the group labeled “African-American”
but the group designated “non-Caucasian/non-African American” and described by
Henderson and Harkey as of “Hispanic, Asian, East Indian” origins. The subjects
with the two highest values for both total cocaine recovered from all segments
and mean cocaine recovered per segment are not African-Americans, but persons
labeled as “Hispanic/Asian/East Indian”. This group of two subjects is the only
group to attain a significant t value with appropriate controls for equality of
variance applied to the analysis.
The
1998 “Race as a Factor” Article
In 1998
Henderson's group published an article again examining “race as a factor
affecting the incorporation of drugs into human hair”, and included nine new
subjects (Henderson, Harkey, Zhou, Jones, Jacob 1998). There was, once again, no description of how
“race” as operationally treated is expressed biologically, and the only reference
to racial categorization is a footnote in their data "Table 1" (p.
157) which notes that “racial characteristics as self described by the
subjects”. Any further connection between "hair type" and race
identification is unexplained. However, the authors frequently refer to “hair
type” and observe that “coarse, dark,
hair may incorporate more drug than fine brown or blond hair”. They do not
identify a specific typology or taxonomy of "hair types", and it
appears that “hair types” are essentially subjective impressions of hair color,
texture, and body: i.e., hair is “coarse” or “fine”, “black” or “brown”,
"wavy" or "kinky", etc. It appears as though the authors
are implying a typological relationship between self-declared race and
"hair type", but there is no explicit description or discussion of this.
There is no reference to the biological literature on hair morphology or any
discussion of sample variability.
The reader must assume, as apparently do the
authors, that the "coarseness" or "fineness" of hair can
readily distinguish races and that hair is dichotomized into these categories.
Problematically, however, virtually all who have studied hair morphology in
relation to race since the 1920’s to the present have rejected such a
characterization (Hausman,
1925; Steggerda, Seibert 1941; Hrdy 1973; Sunderland 1975; Rook 1975; Leach
1975). Hausman, as early as 1925, stated
that it is "not possible to identify individuals from samples of their
hair, basing identification upon histological similarities in the structure of
scales and medullas, since these may differ in hairs from the same head or in
different parts of the same hair". Rook (1975) pointed out nearly 50 years
later out that "Negroid and Caucasoid hair" are "chemically
indistinguishable". In reviewing a series of studies he noted that hair
from various populations and analyzed by a series of tests to determine amino
acid composition, diffractive values for X-rays, stress-strain analysis, and
electrophoretic studies showed "identical results were obtained for all
samples".
The method by which Henderson and Harkey move from
one conceptualization (coarse hair/dark hair) to another (racial bias) is left
unstated. And this is problematic in terms of their statements in the 1996
article that neither pigmentation nor "genotypic expression" is a likely
explanation for these putative differences in "hair type". Their
hypothesis, for example, requires one to assume that “Caucasians” with coarse,
dark hair are somehow be "immune" to the “race effect” they postulate
for “non-Caucasians”. The "race effect" is left to account for the
heightened incorporation of cocaine into “non-Caucasian” hair since they
explicitly exclude the likelihood that a "simple melanin effect" can
account for their results. And, undergirding the analysis, one must assume the
dichotomization of “race” into “Caucasians” and “non-Caucasians” with the
concomitant requirement that an unknown, unidentified unifying "race
factor" binds together all non-Caucasians and excludes all Caucasians.
Does The 1998 Data
Support “Race Bias” in Hair Analysis?
In the 1998 article, with the addition of the 9
new cases, the Henderson et al. group concluded, "there appears to be a
racial bias in the incorporation of cocaine into human hair". However,
regardless of the method by which the data is analyzed, and even accepting the
unorthodox "race dichotomy" of their method, the Study I/Study II
comparison offered in the 1998 article does not show a significant
difference between the Caucasians and “non-Caucasians”.
As indicated earlier, this new data consisted of
the addition of 9 subjects who were characterized as “moderate users of
cocaine” but were not judged to be “cocaine dependent”. They each received a
single dose of deuterated cocaine of 2 mg/Kg of body weight, administered
intranasally by liquid atomization. This was done in order to duplicate and
make comparable this group's cocaine dosing level to the group that formed the
basis of the 1993 study. In this section we will refer to the 1993 study as
“Study 1” and the 1998 additional subjects as “Study 2”.
The nine
additional subjects added in Study 2 were all “non-Caucasians”. Specifically,
the “race composition” (with their hair color and “type” are shown in
parentheses) of the
subjects was as follows:
¨
4 African Americans (all black, all “kinky”)
¨
2 Hispanics (both black, one straight, one wavy)
¨
2 Caucasian/African Americans (one black, one dyed, one kinky, one curly)
¨
1 Arabic/Caucasian (black, wavy)
These nine individuals are contrasted to 6 individuals identified from
Study 1. These six individuals are identified as “Caucasians” and all had brown
hair (one subject had gray/brown hair). Three had “straight” hair, two had
“wavy hair” and one had “curly” hair. It is unexplained if these six were
selected from the Study 1 pool by a random process or whether these six were
picked on some other basis.
Although Henderson et al. in Table III of the 1998
article indicate that the study groups are significantly different at (p =.05),
a re-analysis of this data do not support this observation. An analysis of the
cocaine recovered from the subjects hair of this study and contrasting the
subjects in Study I (Caucasian) to Study II (non-Caucasian) does not show at (p
= .05) by ANOVA, t test, or a series
of non-parametric tests a statistically significant difference between the
groups. Comparing cocaine recovered from all "racial" groups as
included in Study 2 and comparing them to the selected 6 Caucasians from Study
1 by t test yields a finding of no significant difference (t = -1.443, df = 13,
p = .173).
This is true whether or not you include all subjects or whether you exclude the
single “non-Caucasian” who had a zero value for their hair analysis and was
excluded from the analysis by Harkey and Henderson.
With Subject 3 excluded the contrast between Caucasians and non-Caucasians
still fails to attain significance (t = -1.820, df = 12, p = .094).
Furthermore, using the “maximum amount of cocaine found in any hair segment”
also fails to produce a significant difference (t = -.423, df =13, p = .679).
These differences may come about because the authors used specialized
considerations in the application of these tests that were not reported and
consequently we could not duplicate.
Henderson et al. operationally treat their “race
factor” as “differences in the incorporation of drugs into different hair
types”. The authors, in the discussion section, reach the conclusion that
“there appears to be a racial bias in the incorporation of cocaine into human
hair”. However, they state in their summary that “these findings strongly
suggest a racial bias” but “are not conclusive”. They believe that the data is not conclusive because of
"sample size and the high degree of inter-subject variability" and because
"none of the subjects seemed to be true outliers" in the 1998 study.
Such a statement is not warranted by the data and analysis presented in the
1998 paper, and is not warranted in considering the totality of the data from
the 1993 report to the present.
¨
The characterization of sample size and high inter-subject variability as
the limitation on the strength of this data fails to acknowledge or recognize
other serious sample defects. There is no attempt to assess variability by
using groups of samples to represent the "types" which the research
alleges to investigate. This is because an explicit definition of what
constitutes a "type" is undefined. Thus the assumption that
variability is high because of sample size cannot be made. Variability may be high
under any circumstances. That certainly is closer in character with the
historic observations on hair morphology.
¨
The failure to do any random assignment or investigator blinding at any
stage of the assessment is a serious flaw. What would happen to a hair sample
if the researcher assaying it did not know a
priori the "race" of the donor? What would happen if the person
doing the assessment were given samples deliberately selected to be ambiguous
(e.g., "coarse, kinky hair" from a "Caucasian")? If a
"race factor" accounts for serious variability in cocaine
incorporation into hair, could the researchers identify the race of hair
samples to which they were blinded by simply assigning them to categories based
on the incorporation rates of cocaine alone?
¨
In the assignment of traits by staff evaluation - in areas such as hair
color, hair texture, etc. - and the
self-selection of "races", there is a lack of any assessment of
inter-rater accuracy. This does not
allow one to evaluate the degree to which subject variability may come from the
reliance on unassessed impressions of the research staff. One cannot
distinguish the empirical measures of the study from the sociological
perceptions of staff with this design.
¨
The race conceptualization used is one that lacks any grounding in the
historical anthropological literature or any basis in current governmental
guidelines regarding the categorizations of citizens for legal purposes. It
also lacks any clear internal logic, and does not appear to reflect an understanding
of the distinction between race and ethnicity.
¨
Whatever feature of “race" that is targeted is unarticulated, and
one cannot determine whether the “race factor” is present in any particular
individual, and whether the “race factor” is a binary trait (present/absent) or
is a quantitative trait which may be present in degrees. This is important
since most of the subjects of the study categorized as “non-Caucasian” appear
to have racially heterogeneous backgrounds.
¨
There is no articulation of how the “hair types” are related to “race”.
It appears that it is left to some sort of "common sense" or social
stereotype regarding racial appearance. It is curious that the six Caucasian
subjects from study 1 were all selected for brown hair. Why are no black-haired
Caucasians included in the study? Perhaps there are reasons for this, but if
so, they are undiscussed. On what basis other than assumption can one assume
that the hair coloration in these categories is uniform? Are all
"brown-haired" subjects equivalent in coloration?
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