"He's always been an only child that never liked being the only child," McNair said. "He always liked having someone over. He's always had to have guests. He's just an extrovert, to heart. He does not like to be alone."
Purvis is so outgoing in fact, that it changed his family's dynamic three years ago. When AAU teammate Tyreke Coger was bouncing around from house-to-house, living with different family members, Purvis and McNair invited him to live with them.
Purvis liked living with Coger so much he urged his mother to take in two additional foster children two years later. Once the only child, Purvis now has three brothers.
"We're always having fun around the house. We're always playing around, playing video games, having fun," Purvis said. "It's a brother relationship."
You'll notice Purvis uses the word "brother" often and it's not by accident. Just like his foster family members are his brothers, so are the other people on his basketball team.
Upper Room Academy is admittedly small but that's the way Purvis likes it. He gets one-on-one attention from his teachers. He knows just about everyone from grades K-10. And with only 29 students in the ninth and 10th grades, Purvis and his teammates have just about every class together except for math and Spanish.
"It just helps our relationship get better and better," Purvis said. "Every day in the classroom we're learning or we're playing or we're helping each other. That carries over onto the court and helps us bond together more."
Upper Room coach Avie Lester says the small-school environment keeps away a lot of the nonsense Purvis would experience in a public high school. Lester said Purvis doesn't have to build some kind of a persona match his basketball reputation. He can just be himself.
"I have a first-grade daughter and she just looks at him as Rodney, my friend from the 10th grade," Lester said. "She doesn't know anything about what other people think of him."
While Purvis is free to be himself at Upper Room, he's chosen to be the best version of himself he can be. Walking the hallways with elementary school aged kids at school forced Purvis to become more self aware.
"When I first came here I didn't really have a good feel for the atmosphere," Purvis said. "I came here in eighth grade and I would say something and a student would say ‘Whoa, you can't say that here.' It was a big jump I had to take but now it's really good for me because all the kids look up to me and I want to be a good role model."
Purvis' path at Upper Room has clearly been beneficial but it's also been a little confusing from the outside. The church-based school isn't a common destination for high school basketball stars and, until last year, didn't even have high school students.
When Purvis enrolled at Upper Room the school was only kindergarten through eighth grade. But after each year he completed, McNair and the other parents of students asked school administrators to expand the grades they offer -- and they did.
Last spring the school decided it would continue to expand past 10th grade, allowing Purvis and his classmates to become the first high school graduates of Upper Room.
Lester said the process wasn't quite as complicated as you might think. When the school was created in 2000, administrators had the foresight to hire middle school teachers who were also certified to teach high school courses. As Purvis and his classmates advanced, the teachers simply changed which classes they taught.
"When the decision was made to expand, it was a lot of work in a short period of time but it's really been rewarding," Lester said. "We've gotten more students than we thought we would. We've got 29 ninth and 10th graders now. When Rodney was in eighth grade, the graduating class was seven."
In addition to the family environment the school offers, Upper Room also allowed Purvis the luxury of reclassifying for a second time. After choosing to repeat eighth grade, Purvis continued taking several classes on his prior academic track.
This fall Purvis decided to reclassify again, this time back to his original grade, and after taking English III this summer and English IV next year, he'll have everything he needs to graduate.
"All my classes and all my credits will be done next year," Purvis said. "My family didn't think there was a reason for me to stay around in high school for another year, just wasting time."
Since the decision to reclassify, Purvis hasn't had much time to waste at all. Coaches put the athletic combo guard on speed dial and he's received a handful of scholarship offers.
But while his recruitment has progressed quickly in the last month, Purvis said he's not going to let anyone rush him.
"I know it's going to be sometime my senior year. It's going to be a while," Purvis said. "I just want a winning tradition and a great relationship with the coach that I can develop until it's time for me to go to college. Also, one not too far away from home."
And in typical Purvis fashion, he added he might want a friend or two to come with him.
"Hopefully I can team up with my best friend Shabazz (Muhammad)," Purvis said of the Top 5 junior from Las Vegas. "He's really cool. We're basically like the same person."
While Muhammad might not be family now, after a few years playing on the same college team, Purvis should have no problem calling him "brother."