Brothers Evan, 14, and Holden, 10, in their beds before bedtime.

"Holden has a big personality and is always goofing around. He's always inventing new games and making us laugh," says his mom, Heather.

"Evan is very social and gregarious, which is atypical for most children with autism. He loves the outdoors and can spend hours mowing the lawn," says Heather.

Evan touches Holden's head as Holden gets ready for bed.

"When I found out Evan had autism, I didn't want to believe it at first. I went through denial and was deeply depressed. It was like going through a death. Then I thought, 'This is what it is. I don't care how it happened. Let's do what we can.' Acceptance was comfortable," says Heather. "When we saw symptoms in Holden, we knew right away. It was less daunting."

The two brothers snuggle with their mom while they watch a movie.

Heather comforts Holden after an argument begins to escalate with him and Evan. The outburts are less frequent after years of therapy, but their triggers are often small and unknown.

Evan calls his dad, who is out of town, to tell him that Holden has made him very upset. "It's not right," he tells him. Holden is Evan's trigger. While Evan is relatively calm, Holden gets on his nerves and knows how to push him over the edge.

While it's normal for brother to fight, Heather says that it's the brothers' overreactions that make situations more challenging.

Evan and Holden play with their train set.

Evan hugs Holden before Holden gets dropped off at school. Both boys are very loving and affectionate, which is often atypical for children with autism.

Evan, 14, and Holden, 10, are brothers with autism. Evan and Holden relate to each other and will always be there for each other. Understanding how the other feels makes each boy feel less isolated and more normal, says their mother, Heather Pardue. While the brothers share a bond, they also can trigger each other's behavioral issues. Heather says, however, that not everything is about autism; sometimes, it's just about being siblings. Autism is a developmental disorder that can affect a child's development in thinking, language, behavior, and social skills. The current risk for autism in the general population is 1 in 64; but if a boy has an autistic brother, his chance of having the disorder is more than 25 percent.

Holden looks for lemurs at the Greensboro Science Center. He loves all the exhibits and goes to the center with his mom weekly.

Evan and Holden embrace after a fight.

Evan and Holden ask Santa if they are on the "nice" list. Both are asking for the latest SpongeBob SquarePants video game for Christmas.

The two brothers play at the Greensboro Science Center.