A recent study by two Dartmouth researchers hopes to bring the scientific community one step closer to answering the question, "When do we reach adulthood?" Assistant professor of psychological and brain science Abigail Baird and graduate student Craig Bennett studied 18-year-old Dartmouth freshman and determined that their brains matured significantly throughout their freshman year.
The observation that adulthood might be reached much later than traditionally thought could affect national policy, as this research could spawn a reevaluation of 18 as the legal age of adulthood.
"When you're 18 you can enlist in the military and you can vote. It's really a question of, 'Are you an adult at that time?'," Bennett said.
Bennett stressed that relying on physical characteristics to gauge adulthood can oversimplify the issue.
"Once you looked like an adult, people assumed you had adult capabilities. Even though people may look like adults they are still growing in their emotional maturity," Bennett said.
Baird and Bennett interviewed Dartmouth freshman about issues relating to emotional maturity and transition to college life. They chose only to interview freshman who had come from over 100 miles away to ensure that the students could not leave campus every weekend and that they were removed from their familiar support structures.
"During the first year of college, especially at a residential college, students have many new experiences," Baird said. "They are faced with new cognitive, social, and emotional challenges. We thought it was important to document and learn from the changes taking place in their brains."
They conducted their research by interviewing, administering questionnaires and performing MRIs on the subjects. The students took "The Dartmouth College Life Survey" which asked about social life, friends and study habits. Baird and Bennett then followed up with these students throughout their freshman year.
While these questionnaires demonstrated significant changes in emotional adjustment, the changes in MRIs throughout the year were even more conclusive. The researchers discovered specific parts of the brain that had matured during the year. The changes occurred in regions of the brain that integrate emotion and cognition.
The data revealed that the brain of an 18-year-old college freshman looks much different than the brain of someone in their mid-twenties, Bennett said. The study included a control group of 17 older students aged 25 to 35 in order to make accurate comparisons.
Bennett said that he hopes that their research will expand beyond Dartmouth because their findings might not necessarily apply to those teens who chose to enter the work force, stay at home with mom and dad or join the military.
"We want to determine if the environment provokes this change or if it related to the more general stage of life," Bennett said.
Since the results of the study were released just this week, Bennett said that he would know more in the next couple of days about the national response their research has generated.
The researchers acknowledged that scientific research does have the potential to influence public policy, but most students seemed to agree that changing the voting age or moving up the minimum age for military service seems implausible.
"Ideally, there could be a test for maturity, but realistically in American society 18 is usually when people act and think more autonomously, so it's a good age," Josh Mirkin '09 said.
The study entitled "Anatomical Changes in the Emerging Adult Brian" appeared in the Nov. 29 on-line issue of the Journal of Human Brain Mapping. A grant from the National Institute of Child Health and Development funded the research.
