Nature
Ethics: Taboo genetics
Probing the biological basis of certain traits ignites controversy. But
some scientists choose to cross the red line anyway.
* _Erika Check Hayden_
(http://www.nature.com/news/ethics-taboo-genetics-1.13858#auth-1)
02 October 2013
Growing up in the college town of Ames, Iowa, during the 1970s, Stephen Hsu
was surrounded by the precocious sons and daughters of professors. Around
2010, after years of work as a theoretical physicist at the University of
Oregon in Eugene, Hsu thought that DNA-sequencing technology might finally
have advanced enough to help to explain what made those kids so smart. He
was hardly the first to consider the genetics of intelligence, but with the
help of the Chinese sequencing powerhouse BGI in Shenzhen, he planned one of
the largest studies of its kind, aiming to sequence DNA from 2,000 people,
most of whom had IQs of more than 150.
He hadn't really considered how negative the public reaction might be until
one of the study's participants, New York University psychologist Geoffrey
Miller, made some inflammatory remarks to the press. Miller predicted that
once the project turned up intelligence genes, the Chinese might begin
testing embryos to find the most desirable ones. One article painted the
venture as a state-endorsed experiment, selecting for genius kids, and Hsu and
his colleagues soon found that their project, which had barely begun, was
the target of fierce criticism.
There were scientific qualms over the value of Hsu's work (see _Nature
497, 297–299; 2013_ (http://dx.doi.org/10.1038/497297a) ). As with other
controversial fields of behavioural genetics, the influence of heredity on
intelligence probably acts through myriad genes that each exert only a tiny
effect, and these are difficult to find in small studies. But that was only
part
of the reason for the outrage. For decades, scientists have trodden
carefully in certain areas of genetic study for social or political reasons.
At the root of this caution is the widespread but antiquated idea that
genetics is destiny — that someone's genes can accurately predict complex
behaviours and traits regardless of their environment. The public and many
scientists have continued to misinterpret modern findings on the basis of this
—
fearing that the work will lead to a new age of eugenics, preemptive
imprisonment and discrimination against already marginalized groups.
“People can take science and assume it is far more determinative than it is
— and, by making that assumption, make choices that we will come to regret
as a society,” says Nita Farahany, a philosopher and lawyer at Duke
University School of Law in Durham, North Carolina.
But trying to forestall such poor choices by drawing red lines around
certain areas subverts science, says Christopher Chabris of Union College in
Schenectady, New York. Funding for research in some areas dries up and
researchers are dissuaded from entering promising fields. “Any time there's a
taboo or norm against studying something for anything other than good
scientific reasons, it distorts researchers' priorities and can harm the
understanding of related topics,” he says. “It's not just that we've ripped
this page
out of the book of science; it causes mistakes and distortions to appear
in other areas as well.”
Here, Nature looks at four controversial areas of behavioural genetics to
find out why each field has been a flashpoint, and whether there are sound
scientific reasons for pursuing such studies.
1 INTELLIGENCE
Taboo level: HIGH
The comments that Miller made about Chinese families and the government
wanting to select for intelligent babies touched a nerve still raw after many
years. In the nineteenth century, British anthropologist Francis Galton
founded the eugenics movement on the premise that extraordinary abilities, as
well as deficits, were inherited. The movement led to abuses, such as
forced sterilization of people deemed mentally inferior — generally
minorities,
poor people and especially people with mental illnesses — in countries
around the world, including Germany, the United States, Belgium, Canada and
Sweden.
The term 'intelligence' is also a slippery one. Intelligence tests don't
measure a wholly innate ability; it is possible, for example, to improve
one's scores with practice. Nevertheless, about 50% of variability in
intelligence seems to be inherited, posing an irresistible puzzle to some
researchers. No one gene has been linked strongly to intelligence and many
that have
been weakly linked have also been questioned_1_
(http://www.nature.com/news/ethics-taboo-genetics-1.13858#b1) .
Earlier this year, in an attempt to find stronger genetic correlations,
Chabris and a large international group of colleagues examined the genomes of
more than 125,000 people and found three genetic variants, each of which
had a small effect on the length of an individual's school career_2_
(http://www.nature.com/news/ethics-taboo-genetics-1.13858#b2) . The authors
speculated that the variants' influence on educational attainment came from
their
effect on intelligence. But the results triggered the usual rounds of
condemnation and concerns over eugenics. Other detractors argued that such
studies take the focus and funding away from other, non-genetic, factors such
as
poverty, which have a much greater effect on social mobility.
Chabris says that the work can actually contribute to greater social
mobility — for instance, by helping to identify preschoolers who could be
helped
by more intensive early childhood education. “The fact that people in the
past interpreted the results in a certain way doesn't mean that it shouldn't
be studied,” he says. But not everyone buys that potential misuses of the
information can be divorced from gathering it. Anthropologist Anne Buchanan
at Pennsylvania State University in University Park wrote on the blog The
Mermaid's Tale that rather than being purely academic and detached, such
studies are “dangerously immoral”.
Like all online polls, the results are susceptible to online campaigns and
gaming. Please interpret the results with care.
Critics of the BGI project also point to signs that its data could be
misused. After this summer's furore over Miller's interview, Hsu played down
the
potential for abuse. “There's a big gap between finding a few hits and
finding thousands of hits — enough to predict the trait on the basis of the
genotype — and we were never saying we were going to get to that point,” he
says. But in 2011, before the uproar over the study, Hsu told Nature: “I'm
100% sure that a technology will eventually exist for people to evaluate
their embryos or zygotes for quantitative traits, like height or
intelligence. I don't see anything wrong with that.”
One of Hsu's collaborators, behavioural geneticist Robert Plomin of King's
College London, says that such talk has not been helpful. But after
studying intelligence for 40 years, he has high hopes that this project and
other
sequencing ventures will help to pinpoint the many genetic contributors to
the trait. Like Chabris, he says that the work could be used to target
educational interventions. Moreover, like all of the intelligence researchers
interviewed for this story, he says it is a fundamentally human trait and
that it is worth searching for a genetic contribution. “I'm optimistic that
we will find it,” he says. “I'm not going to quit until we do.”
2 RACE
Taboo level: VERY HIGH
As far as genetic taboos go, race is probably one of the most heavily
policed from within the scientific community, largely because of the way
researchers have examined its intersection with other controversial traits,
such
as intelligence. This is due mostly to suspicion about what motivates the
study. There is broad consensus across the social and biological sciences
that groups of humans typically referred to as races are not very different
from one another. Two individuals from the same race could have more genetic
variation between them than individuals from different races. Race is
therefore not a particularly useful category to use when searching for the
genetics of biological traits or even medical vulnerabilities, despite
widespread assumptions.
Most researchers who examine genetic differences between populations take
care to point out that the differences they observe reflect the geographic
origins, reproductive history and migrations of these groups, not markers of
some essential differences between them.
However, some researchers have asked whether the taboo on the genetics of
race has become so severe that it bars legitimate research. In 2005, for
instance, geneticist Bruce Lahn of the University of Chicago in Illinois
published studies_3_
(http://www.nature.com/news/ethics-taboo-genetics-1.13858#b3) , _4_
(http://www.nature.com/news/ethics-taboo-genetics-1.13858#b4)
suggesting that variants of two brain-development genes possibly linked to
intelligence are evolving differently in white Europeans and African ethnic
groups. This provoked a wave of worried comments by scientists about how the
studies might be interpreted. Among those who voiced concerns was
then-director of the US National Human Genome Research Institute Francis
Collins, now
director of the National Institutes of Health (NIH) in Bethesda, Maryland.
Like all online polls, the results are susceptible to online campaigns and
gaming. Please interpret the results with care.
Lahn and his co-authors eventually found that the gene variants under
selection were not linked to elevated intelligence_5_
(http://www.nature.com/news/ethics-taboo-genetics-1.13858#b5) . But that
report garnered little
attention compared with the explosive studies that came before it. Lahn says
he
felt “ambushed” during the debate over his findings. At meetings, even his
co-authors did not defend him. “My friends said nothing,” he says.
Some argue that Lahn should have been more cautious. “Science always plays
out in a certain socio-political context, and you have to look at the
consequences of how the science might play out,” says John Horgan, a journalist
who has written widely on the societal implications of science. “Research
on race and intelligence is much more prone to supporting racist ideas about
the inferiority of certain groups, which plays into racist policies.”
Horgan says that institutional review boards should ban or seriously question
proposed studies on race and IQ.
Lahn no longer works on the genetics of race and has urged researchers to
have a more transparent discussion about whether such studies should proceed
at all. “Given the history of the way race has been used in this country,
maybe the research shouldn't be encouraged because it touches too many raw
nerves. I'm OK with that,” he says. “But I'm not OK with being ambushed by
political discussions masquerading as scientific discussions.”
3 VIOLENCE
Taboo level: MILD
A decade ago, forensic psychiatrist Tracy Gunter of Indiana University in
Indianapolis was spending her time trying to help people to overcome the
behavioural and substance-abuse disorders that had led to their entanglement
in the criminal-justice system. But it was becoming increasingly clear to
her that once a client fell into an abuse–crime spiral, it was very difficult
to bring them back.
It was around this time that researchers reported that people with a
certain version of a gene called monoamine oxidase A (MAOA) have some
protection
from the effects of childhood abuse_6_
(http://www.nature.com/news/ethics-taboo-genetics-1.13858#b6) . Other people
who express low levels of the
protein it encodes are more likely to commit crimes if mistreated.
Gunter switched fields to work in behavioural genetics, hoping to find ways
to identify and preemptively treat high-risk individuals. She soon found
her work complicated by the difficulty of defining criminal behaviour
precisely; the impossibility of separating environmental and innate
influences;
and, again, the emerging consensus that behaviour is influenced by numerous
small genetic factors. Ten years on, she says, “the simplistic notions I
had about behavioural genetics when I started this work are not true”.
Despite these caveats — and the fact that some studies have failed to
replicate the original MAOA finding_7_
(http://www.nature.com/news/ethics-taboo-genetics-1.13858#b7) — some lawyers
have used MAOA gene tests, combined
with history of childhood abuse or life stress, to try to mitigate sentences.
In 2009, such testing led to a lesser charge for a Tennessee man who killed
his wife's friend, and it convinced a judge in Italy to reduce a
murderer's sentence by one year (see Nature http://doi.org/cttbjt; 2009). But
juries
are often underwhelmed by genetic testimony: in the United States in 2008,
for instance, defence lawyers attempted to convince a jury to be lenient
towards a boy who had shot a bus driver. They presented evidence that the
boy had a variant of a promoter of a serotonin transporter gene, SLC6A4, that
is linked to depression in people under stress. The jury found the boy
guilty of first-degree murder anyway. Outcomes are mixed, Farahany says,
perhaps because the research is so oblique. “It doesn't seem to be enough to
persuade judges or juries to change guilt or sentencing,” she says. William
Bernet, a forensic psychiatrist in Nashville, Tennessee, adds that, “a
genetic result does not directly cause a person to behave in a particular way.
Juries seem to understand this”.
Like all online polls, the results are susceptible to online campaigns and
gaming. Please interpret the results with care.
That may change as the science progresses, but so far genetics has held no
more sway than conventional mitigating factors, which often include the
milieu in which a person grew up.
Those two domains are coming together as researchers look for more clues to
the environmental factors that interact with genetics in influencing
behaviour. Gunter was part of a team that showed that certain epigenetic
modifications on the MAOA gene are linked to substance abuse in adult women_8_
(http://www.nature.com/news/ethics-taboo-genetics-1.13858#b8) , and these
modifications are influenced by a history of smoking. “Every year that I work
in this field has been a lesson that it's not just genes or environment,”
she now says. “It's genes and environment that matter.”
Scientists continue to look at the genetics of violence, and of conditions
such as psychopathy, although the tension between those who focus on just
genes and those looking for genetic and environmental contributors is high,
says James Tabery, a philosopher at the University of Utah in Salt Lake
City. “My sense is that we're in a holding pattern; it's not clear what's
going to happen next” — specifically because not many genes have been linked
to violence and attempts to replicate the MAOA findings have produced mixed
results.
4 SEXUALITY
Taboo level: MILD
Sometimes, shifting political winds can destigmatize research. In 1993, for
instance, geneticist Dean Hamer, then at the US National Cancer Institute
in Bethesda, encountered a firestorm of criticism from political
conservatives when he published a report suggesting that a region of the X
chromosome
might be linked to homosexuality_9_
(http://www.nature.com/news/ethics-taboo-genetics-1.13858#b9) . Scientists
also criticized some aspects of his
work. Today, studies on the genetics of sexual orientation have been embraced
by the US gay community. The successful campaign to strike down a 2008
California ballot measure that banned same-sex marriage enlisted evidence that
homosexuality has some basis in genetics. And the NIH has designated
research on lesbian, gay, bisexual, transgender and intersex people a
priority. “
The tables have turned tremendously,” says geneticist Eric Vilain,
director of the Institute for Society and Genetics at the University of
California, Los Angeles.
But that does not mean that all research into the genetics of sexuality
will be equally welcome, he adds. Vilain, for example, wants to study the
epigenetics of homosexuality, in search of environmental influences that might
affect the trait. The work hasn't been funded, but he predicts that if it
is, it could upset some gay rights activists who have seen their cause
benefit from the 'hardwiring' theory. He is keeping his fingers crossed. “I
hope
that now that there have been significant social advances, that scientists
can do their work in peace,” he says.
Like all online polls, the results are susceptible to online campaigns and
gaming. Please interpret the results with care.
Such complexities are unavoidable in a democratic society in which citizens
have a say on how public money is spent. Researchers must acknowledge that
and take part in the broader conversation about the kinds of topics they
want to pursue, Farahany says. “You hear this refrain in lots of areas of
science, that because people will misuse science we shouldn't engage in
scientific inquiry. I think that gets it backwards. If we're worried that
people
will misuse it, we need to create safeguards — and an open public dialogue
that ensures responsible use.” That, rather than censoring science or
ignoring its implications, is perhaps the only way that Vilain and other
researchers will get their wish: to do their work in peace.
Journal name:
Nature
Volume:
502,
Pages:
26–28
Date published:
(03 October 2013)
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