His coach at Millville, Jason Durham, said there are times at practice when White will "take it easy" on his teammates.
But then classes end on Friday afternoons and the Thunderbolts begin to narrow their focus to the football game that evening and White becomes a different guy.
"Ask my friends. I don't even crack a smile," White said the other day between weight-training and film sessions. "I get in a zone."
White is a Penn State recruit and perhaps the best defensive lineman in South Jersey because of his ability to transform from an affable, easygoing young man into a disruptive force on the football field.
He is the leader of a Millville team that looms as a serious contender in the Cape-Atlantic League's American Division as well as South Jersey Group 5.
"He has so many natural gifts," Durham said. "He's got size, speed, strength. But the thing about Antoine is that he's a very coachable player. He listens to coaching. He works very hard in trying to get better."
White committed to Penn State after considering offers from around 20 programs, including Boston College, Georgia Tech, Michigan State, Syracuse, Vanderbilt, Duke, Pitt, Maryland, and Rutgers.
White said he initially was hesitant about Penn State because of the NCAA sanctions against the Nittany Lions.
"In the beginning, they did [concern him]," White said of the sanctions. "But really, we're still going to play 12 games against great competition in the Big Ten. That's plenty of exposure."
White has met with the guidance department at Millville and confirmed that he can earn his diploma in December - although he hopes to return in the spring to attend senior events such as the prom and walk at graduation with his classmates.
He believes enrolling at Penn State in January will give him a jump on education as well as his athletic career.
"I'll be six months ahead with my academics," White said. "I'll be lifting [weights] for six months in a Penn State program. I'll be there for spring" football in 2014.
"I really think it can slingshot me forward to pursue my dream."
White hopes to play in the NFL, a goal he set nearly 12 years ago.
"My mom has a video of me when I'm 6 years old and she asks me what I want to be and I say, 'football player,' " White said.
White said there were times early in his athletic career, even as recently as his sophomore season, when his easygoing nature worked against his efforts to realize fully his potential.
He said things changed last season, when he started to sense the opportunity in front of him.
"Junior year was my breakthrough year," White said. "I realized what I could do. Now, I'm a different person when that bell rings on Friday afternoon. I listen to my music, and I don't say anything to anybody.
"I'm focused on football. I don't put my helmet on to lose."
Durham said White is about as pleasant and friendly an athlete as he has ever coached - for most of the week.
"On Friday nights, he's plenty mean," Durham said.