Eugenics
Research Methods
David
Micklos, Cold Spring Harbor Laboratory
Although
eugenics became a popular movement in the United States, at its core was
a research effort to apply Mendel's laws to the inheritance of human traits.
Eugenics researchers attempted to trace the inheritance of a trait through
a family tree, or pedigree. They sought to recognize basic patterns of
inheritance that Mendel had presented in his original 1865 paper on peas.
Beginning in 1900, Mendelian inheritance was extended to other plants,
to animals, and to humans.
Mendel
stated that each visible trait is governed by a pair of "factors" (later
called genes). One member of each gene pair is inherited from the mother
and one from the father. Genes may be dominant or recessive. A recessive
trait is seen ("expressed") only when two recessive genes are inherited
– one copy from each parent. A dominant trait is expressed when a dominant
gene is inherited from one parent and a recessive gene from the other,
or when a dominant genes are inherited from both parents. A sex-linked
trait is expressed when males inherit a recessive gene on their single
X chromosome.
By
examining family pedigrees, eugenicists attempted to discern the pattern
of one of these three basic modes of inheritance -- recessive, dominant,
or sex-linked. Then, as today, the study of gene inheritance involves
two important elements: 1) finding relatively large families that express
the trait under study and 2) "scoring" each family member for the presence
or absence of the trait. Eugenicists faired well on the first element,
because large families were much more common in the first decades of the
20th century.
However,
scoring traits was a difficult problem, especially when eugenicists attempted
to measure complex traits (such as intelligence or musical ability) or
complex mental illnesses (such as schizophrenia or manic depression).
In general, eugenicists were lax in defining the criteria for measuring
many of the "traits" they studied, and they were too quick to force their
data to fit into simple Mendelian templates. It is important to remember
that during the entire reign of eugenics, DNA had not yet been shown to
be the molecule of heredity. Today, genetic researchers use DNA "markers"
to follow trait inheritance. The presence or absence of the marker can
be scored with great certainty. However, eugenicists had no physical road
marks to help them follow inheritance through a family.
Several
organizations in the United States were prominent in organizing and encouraging
eugenics research: the Eugenics Record Office (ERO), the American Breeders
Association (ABA), the Race Betterment Foundation, and the American Eugenics
Society (AES). The ERO, established in 1910 at Cold Spring Harbor, New
York, probably did the most to promote eugenics research. ERO founder
Charles Davenport published several influential booklets that helped standardize
nomenclature for pedigree studies. Budding eugenics researchers convened
at Cold Spring Harbor each summer to learn how to conduct "field work"
– interviewing subjects, taking medical histories, and constructing pedigrees.
Much
eugenical information was submitted voluntarily on questionnaires–such
as ERO's "Record of Family Traits" and "Family Tree Folder" – which coordinated
family geneology with traits and medical conditions. Some families were
proud to make known their pedigrees of intellectual/ artistic achievement,
while others sought advice on the eugenical fitness of proposed marriages.
One interesting subset of personal data were the "calling cards" of circus
acts collected, and often annotated with pedigrees, by ERO workers. On
the midways of Coney Island, eugenics researchers found circus performers
who displayed a range of physical differences – from giantism, to dwarfism,
polydactyly, and hypertrichosis. In one notable case, Charles Davenport's
correspondence with an albino family, resulted inthe first Mendelian study
of this condition, published in the Journal of Human Heredity.
Eugenicists
also used data pooled from insane asylums, prisons, orphanages, and homes
for the blind. Surveys filled out by superintendents were used to calculate
the ethnic makeup of societal "dependents" and the costs of maintaining
them in public institutions. With the mobilization for World War I, anthropomorphic
and intelligence data became available for tens of thousands of men inducted
for the draft. Robert Yerkes developed a test for the innate intelligence
of army recruits. Foreign born recruits were much more likely to do poorly,
probably because it was as much a test of American popular culture as
of intelligence.
Harry
Laughlin, director of the ERO, used these data sources in his testimony
as "expert agent" for the Committee on Immigration and Naturalization
of the U.S House of Representatives in the early 1920s. During three separate
testimonies he presented data that purported to show that southern and
eastern European countries were "exporting" genetic defectives to the
United States who had disproportionately high rates of mental illness,
crime and social dependency. A casual look at Laughlin's testimony will
turn up examples of the ways he "skewed" some data and downplayed other
data to fit his bigoted vision of America.
Eugenicists
disseminated their research in journals and monographs, and presented
seminars and posters at scientific meetings. The International Eugenics
Congresses of 1921 and 1932 were the largest and most prestigious gatherings.
However, many published works of eugenicists were short on data and long
on anecdotal information. Eugenical News, published by the ERO
from 1920-1938, was the dominant mouthpiece for the racist and anti-immigration
agenda of eugenics research. By contrast, the more moderate journal Eugenics,
published by the AES, lasted only three years (1928-31).
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