EMBARK | THE BIG IDEA
the beach one evening contemplating life; I was born
this way. The genetic components to human sexuality
are still muddy, but it is clear that it’s not a choice.
Regardless of our sexual orientation, we seem to
have an innate sense of the attributes we find desir-
able in a mate. Features such as a shapely mouth,
sparkling eyes, and lush hair are widely appreciated
as attractive. And studies show that more attractive
people are likelier to get a job, make more money,
find a mate—even be found “not guilty” if on trial.
Evolutionary psychologists remind us that at our
core, virtually everything we do emerges from a sub-
conscious urge to survive and reproduce our genes,
or lend support to others (such as family) who carry
genes like our own. They further postulate that many
of the physical traits that we consider attractive are
signs of physical health and fitness—in other words,
good genes to let swim in our pool.
Science has also provided a little comfort as to why
your amorous advances are sometimes spurned. A
famous study had women sniffing the underarms
of T-shirts worn by men and then ranking the odor.
The more similar the men’s and women’s immune
system genes were, the worse the T-shirt stank to the
women. There is a sound evolutionary explanation
for this: If parental immune genes are too similar,
the offspring will not be as well equipped to fight
pathogens. In this case, genes used odor receptors as
a proxy to size up whether a potential mate’s DNA is
a good match. Studies like this affirm that chemistry
between people really is a thing. Perhaps we should
not take another’s romantic disinterest personally
but view it more like organ rejection.
Somewhat distressed at the level of control genes
seem to exert over our choices in life, I investigated
an area that I was sure would be impervious to the
reach of DNA: our taste in political leaders. It’s easy
to imagine genes playing a role in whether someone
is right- or left-handed, but whether a person leans
politically to the right or left? I thought not. Yet as
unlikely as it seems, the votes are in, and DNA has
scored another victory.
Scientists have uncovered distinct personality
traits that tend to be associated with people on oppo-
site ends of the political spectrum. In general, liberals
tend to be more open-minded, creative, and novelty
seeking; conservatives tend to be more orderly and
conventional, and to prefer stabil-
ity. Identical twins separatedPHOTO: TERJE DOKKEN, GONZALES PHOTO/ALAMYat birth and raised in different environments typi-
cally find their political stances in agreement when
reunited, suggesting a genetic component to our
political compass. Several studies suggest that vari-
ations in our dopamine D4 receptor gene (DRD4)
influence whether we vote red or blue. Dopamine is
a key neurotransmitter in the brain, associated with
our reward and pleasure center; variations in DRD4
have been tied to novelty seeking and risktaking,
behaviors more commonly associated with liberals.
Other research has shown that certain areas in
the brain are different for liberals and conservatives,
and this may affect how they respond to stressful
stimuli. For example, conservatives tend to have a
larger amygdala, the fear center of the brain, and have
stronger physiological reactions to unpleasant pho-
tos or sounds. Considered together, these biological
differences may partially explain why it’s so difficult
for a liberal or conservative to get the other to “see
the light.” You’re asking people not just to change
their mind but also to resist their biology.THESE EXAMPLES ARE JUST the tip of the iceberg. The
truth is, every human behavior—from addiction
to attraction to anxiety—is tethered to a genetic
anchor. This is not to say that we’re destined to be
slaves of our DNA, however. DNA has built human
beings a brain so magnificent that it has figured out
DNA’s game. And with the advent of gene editing,
we have become the first species capable of revising
our genetic instructions.
Science has shown that you are not who you think
you are. There are biological gremlins driving every
action and personality trait that you assumed were
of your own volition. This realization is dishearten-
ing at first, but knowledge is power. Knowing the
molecular basis of our adverse behaviors should
put us in a better position to curb or remedy them;
accepting that other people have little choice in how
they came to be should engender more empathy
and compassion. Perhaps, with the confidence that
we are not in total control, we can resist the urge to
praise or blame and seek understanding instead. jBill Sullivan is a professor of pharmacology and micro-
biology at the Indiana University School of Medicine,
where he studies infectious disease and genetics. His
book Pleased to Meet Me: Genes, Germs, and the
Curious Forces That Make Us Who We Are is available
where books are sold and at shopng.com/books.Death-defying DNA
HOW OZZY OSBOURNE’S GENES MAY
PLAY INTO HIS HEAVY METAL LIFESTYLEDuring his 50-year heavy
metal music career, Ozzy
Osbourne has become
famous for his alcohol and
drug binges. To learn what
allowed Osbourne to sur-
vive cocaine for breakfast
and four bottles of cognac
a day for decades, scien-
tists analyzed his DNA in- They found a never
before seen mutation in
a gene that’s involved in
breaking down alcohol.
They also found variations
in genes linked to drug
absorptions, addiction,
and alcoholism—varia-
tions that would make
Osbourne six times as
likely as an average person
to crave alcohol and 1.3
times as likely to have
a cocaine addiction. —BS