"I bet there are a lot of students who do drink and do drugs, and I bet they cause problems. Colin would not," said Carlson, who described her son as "well-rounded" and "the opposite of a wallflower."
Nancy Green, the executive director for the National Association for Gifted Children, said college's concerns about exposing a 12-year-old to the freshman experience were understandable.
"The decision to send a young child to college does depend somewhat on the child's social and emotional development," Green said.
"On the face of it [it] makes sense that colleges [would be concerned about a 12-year-old] because a campus is a place where kids live independently for the first time and universities have trouble controlling 18-year-olds most of the time."
But she said her organization believes extremely bright students like Colin should not have their academic opportunities limited solely because of age. Some students, she said, are ready to handle the academic and the social rigors.
"Certainly we want a child to be challenged academically at every stage, and if the other factors [such as social and emotional readiness] fall into place we do think college is appropriate," she said. "But often if the kids are stimulated academically, the other pieces fall into place."
Green said that when gifted children see their options limited, they can face obstacles that aren't there for students who excel in other areas.
"There is a lot of resistance against gifted children," she said. "It's not like a star athlete, who immediately, upon showing they're great at something, they get a special team and a great choice."
Despite reluctance by school administrators, Colin and his mother told ABCNews.com that several professors who had met with him expressed disappointment when they learned he would not be on campus this fall.
Peter Siver, a botany professor and the director of environmental studies at Connecticut College, told ABCNews.com that he was anxious to have Colin become a part of his research team.
"Academically I don't think there's any question he would have been able to handle being here," said Siver, who met Colin during an incoming freshman visitation weekend and kept in touch with him through e-mail. "I think at a place like this Colin could have blossomed and done research with me and maybe even expanded on it."
"I joked with my class that they were going to be bumped by Colin -- he had way more questions then my students ever had," he said.
Carlson told ABCNews.com that while her son's SAT scores and IQ are off the charts -- she declined to disclose his exact numbers -- he still faced a lot of wary admissions counselors who seemed hesitant to bend the rules to accommodate his young age.
She said admission counselors at another small New England liberal arts college told Colin that, while they'd love to have him at the school, they simply could not waive the residency requirement that the other students must adhere to. Because Colin was too young to live alone in a dorm, Carlson said the school instructed Colin to go back to high school until he was of age -- and then apply again.
But Colin didn't want to go through another four years of high school.