LOS ANGELES, Sept. 5 (Xinhua) -- Variations in dopamine gene may play a role in the poor academic performance of adolescents, a new study suggests.
To determine the genetics' impact on academic success, researchers at the Florida State University performed their groundbreaking analysis using DNA and lifestyle data from a representative group of 2,500 U.S. middle- and high-school students who were tracked from 1994 to 2008 in the National Longitudinal Study of Adolescent Health.
The findings showed that the academic performance of adolescents will suffer in at least one of four key subjects -- English, math, science, history -- if their DNA contains one or more of three specific dopamine gene variations.
For instance, the researchers found a marginally significant negative effect on English grades for students with a single dopamine variant in a gene known as DAT1, but no apparent effect on math, history or science. In contrast, a variant in the DRD2 gene was correlated with a markedly negative effect on grades in all four subjects. Students with a single, DRD4 variant had significantly lower grades in English and math, but only marginally lower grades in history and science.
"We found that as the number of certain dopaminergic gene variants increased, grade point averages decreased, and the difference was statistically significant," said lead researcher Kevin M. Beaver, a biosocial criminologist at the University. "For example, the GPA of a student with specific variants of three dopaminergic genes might be around 2.8, versus a GPA of around 3.3 without the variants. That could mean the difference between being accepted into a college versus being rejected."
"Unfortunately, we know that students with lower GPAs are generally more likely to participate in antisocial or criminal activities, and less likely to attend college and earn comparatively higher salaries as a result," said Beaver.
The researchers also uncovered a correlation between the variants of dopamine genes that a student possessed and his or her GPA in different subject areas.
The research sheds new light on the genetic components of academic performance during middle and high school, and on the interplay of specific genes and environmental factors such as peer behavior or school conditions.
"We believe that dopaminergic genes affect GPA because they have previously been linked to factors associated with academic performance, including adolescent delinquency, working memory, intelligence and cognitive abilities, and ADHD, among others," Beaver said in the study published in the latest issue of the journal Intelligence.
"So, the genetic effect would operate indirectly via these other correlates to GPA and school performance," Beaver added.
But the researchers noted that genetic liability for low GPA could be moderated by environmental conditions such as school structural characteristics, teacher performance, or behavior of other students.
"If that is true, then findings such as ours could help lead to more effective, innovative ways of enhancing school and individual performance," Beaver noted.