Researchers have identified genetic markers
that may influence whether a person finishes high school and goes on to
college, according to a national longitudinal study of thousands of young
Americans.
The study is in the July issue of
Developmental Psychology, a publication of the American Psychological
Association.
"Being able to show that specific
genes are related in any way to academic achievement is a big step forward in
understanding the developmental pathways among young people," said the
study's lead author, Kevin Beaver, PhD, a professor at the College of
Criminology and Criminal Justice at Florida State University.
The three genes identified in the study --
DAT1, DRD2 and DRD4 -- have been linked to behaviors such as attention
regulation, motivation, violence, cognitive skills and intelligence, according
to the study.
Previous research has explored the genetic
underpinnings of intelligence but virtually none has examined genes that
potentially contribute to educational attainment in community samples, said
Beaver.
He and his colleagues analyzed data from
the National Longitudinal Study of Adolescent Health, also known as Add Health.
Add Health is a four-wave study of a nationally representative sample of
American youths who were enrolled in middle or high school in 1994 and 1995.
The study continued until 2008, when most
of the respondents were between the ages of 24 and 32. The participants
completed surveys, provided DNA samples and were interviewed, along with their
parents. The sample used for this analysis consisted of 1,674 respondents.
The genes identified in this research are
known as dopamine transporter and receptor genes. Every person has the genes
DAT1, DRD2 and DRD4, but what is of interest are molecular differences within
the genes, known as alleles, according to Beaver.
Subjects who possessed
certain alleles within these genes achieved the highest levels of education,
according to the findings.
Dopamine transporter genes assist in the
production of proteins that regulate levels of the neurotransmitter dopamine in
the brain, while dopamine receptor genes are involved in neurotransmission.
Previous research has shown that dopamine levels play a role in regulating
impulsive behavior, attention and intelligence.
The presence of the alleles alone did not
guarantee higher levels of education, the study found. Having a lower IQ was
more strongly associated with lower levels of education. Also, living in
poverty and essentially "running with a bad crowd" resulted in lower
levels of education despite the genetic effects.
Even though the genetic variants were found
to be associated with educational levels, having a specific allele does not
determine whether someone will graduate from high school or earn a college
degree, according to Beaver.
Rather, these genes work in a probabilistic
way, with the presence of certain alleles simply increasing or decreasing the
likelihood of educational outcomes, he said.
"No one gene is going to say, 'Sally
will graduate from high school' or 'Johnny will earn a college degree,'"
he said.
"These genetic effects operate
indirectly, through memory, violent tendencies and impulsivity, which are all
known predictors of how well a kid will succeed in school. If we can keep
moving forward and identify more genetic markers for educational achievement,
we can begin to truly understand how genetics play a role in how we live and
succeed in life."
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