LOS ANGELES -- "I want to go home," Thomas Robinson said as he climbed into his mother's arms, wrapped his tiny body around her torso and nuzzled his head against her neck.

The 8-year-old, who stars with Jennifer Aniston and Jason Bateman in "The Switch," was experiencing his first big movie premiere. It was nearing 10 p.m. at Hollywood's nouveau W Hotel, where a party was being held to celebrate the film's release. Well-groomed industry types abounded, sipping martinis, delicately eating shrimp skewers, taking smoke breaks on a dimly lighted patio.

Thomas, meanwhile, smiled meekly and picked at a plate of pigs-in-a-blanket as scores of adults came by to tell him how cute he was. He even received a high-five from co-star Patrick Wilson. But when the camera flashes got too relentless, he recoiled. His mom, Rachel, quickly gathered their things and headed for the exit.

Only hours before, Thomas' performance as Sebastian, the bright son of Aniston's character, had coaxed a chorus of "awws" from a full theater, the latest in a series of strikingly naturalistic and evocative child actors anchoring movies this summer.

In July, there was "Ramona and Beezus," based on Beverly Cleary's book series, starring an 11-year-old girl, Joey King. That was followed by Rob Reiner's "Flipped," a 1960s tale of young love centered on 14-year-old Madeline Carroll and 15-year-old Callan McAuliffe.

Upcoming in October is the vampire remake "Let Me In," with 13-year-old Chloe Moretz and 14-year-old Kodi Smit-McPhee.

In "The Switch," Thomas has a kinship with a character played by Bateman, who himself was a child actor on television. Growing up in Hollywood has never been easy, as evidenced by the complicated legacies of stars such as Judy Garland and Robert Blake. But in an era when kids submit their own auditions to casting directors via YouTube and reality television can instantly propel a precocious youngster from obscurity to fame, the pool has never been quite this competitive.

And, according to many in the industry, the wealth of opportunity on the big screen had led many aspiring young actors to "over-prepare," rehearsing relentlessly with coaches or stage parents to hone their acting skills.

Trying to act professional when you're just a kid can be a lot to balance, said Bateman.

"I wasn't as young as (Thomas) is, but I can remember being around all these adults and trying to sort of accelerate my ability to be professional or deliver the goods," he said. "Kids at that age are really just thinking about executing their homework properly or putting the soccer ball in the net. They have a different set of pressures."

Rachel Robinson, Thomas' mom, said her son followed his older brother, 10-year-old Bryce, into movies after Bryce was cast in "Marley & Me" and "Valentine's Day."

"We're kind of just rolling with it," she said of her sons' success. "And if they ever don't want to put the work in and don't want to do it -- they own the process. It's their hobby. If they'd rather be running around outside, fine."

North Hollywood resident Thomas, meanwhile, is grappling with how to handle his first movie role. Too shy to talk to a reporter directly, Thomas had his mother relay questions. Asked how he felt about the film's release, he replied: "Sort of freaked out."

Kodi Smit-McPhee, one of the stars of "Let Me In," said his father, Andy McPhee, also an actor, often accompanied him on the set, easing the pressure of filmmaking.

"My dad, he is always kind of my courage," said Kodi, who's from Australia. "He taught me everything I know, and the way we do it is to try to make it real -- a whole life for the character, all the little things. He'll be there if I need help with a dramatic scene."

Madeline Carroll, the actress from "Flipped," said her mother serves a more strict role in her life: making sure she puts away the money she's making.

On the set of "Flipped," Madeline said, director Rob Reiner worked hard to kid-proof the environment, even using a "swear jar" for anyone who used unsavory language in front of the young cast.

"If you swore, you had to put 20 bucks into the jar," said Madeline, who lives in Simi Valley. "When I'm 14, I've noticed adults are starting to curse around me and stuff, like they don't care anymore, because they think I'm older. Me and my family, we're Christian, so when (adults) are talking about certain things, I just sit quietly."

Reiner praised Madeline's maturity on set. "It was none of that fake kind of cutesy acting that sometimes you see with young kids," he said.

In contrast, Reiner remembers the challenges of directing kids with "very little to no experience" in "Stand by Me," the 1986 coming-of-age classic about young boys bonding over a summer weekend. During one dramatic scene in which the best friends are about to be run over by a train, Reiner said, he tried diligently to get the cast "revved up."

"I had to work myself up into a lather and pretend I was mad at them," he laughed. "I said, 'The men pushing the dolly are tired, and the reason I have to keep doing this is because of you!' And they started crying, and I said, 'Roll the camera!' "

Interestingly, being "over-rehearsed" can kill the spontaneity of a performance, said Nina Jacobson, who produced March's "Diary of a Wimpy Kid," starring 12-year-old Zachary Gordon.

"A lot of times, they have just rehearsed so much, and they're trying so hard that it's heartbreaking," said Jacobson, a former Disney studio executive. "They're putting so much effort and their heart and souls into it. But when there's that rehearsed quality, it doesn't feel like a human being that you might know."

Christian Kaplan, who cast Joey King as Ramona Quimby, said she won the part because she acted like an actual kid during the auditions.

Joey said she didn't really feel any pressure to perform for "Ramona and Beezus," although she and her mother "cried tears of happiness" when she got the role.

"I knew what to do on set because I had experience from TV, but I wasn't nervous," she said. "I was just so excited to be playing Ramona, and to play the lead, it was a big responsibility. My friends were just so excited for me. My friends were kind of jealous that I got to hang out with (co-star Selena Gomez), but I was like, 'Guys, she's just a regular person like us.' I never really feel star-struck. We're all in the same business."

While Joey may be enjoying the process now, it remains to be seen how the experience will affect her career. Many child actors, like Jonathan Lipnicki of "Jerry Maguire" and "The Sixth Sense" star Haley Joel Osment, have struggled to find their place in Hollywood after outgrowing their cute looks.

Anna Chlumsky, perhaps best known for her role in 1991's "My Girl" opposite Macaulay Culkin, said she had trouble finding work and was constantly rejected as she developed into a curvy teenager.

"I have realized that there really is a sense of before 'My Girl' and after 'My Girl' in my life, and I can only try to pretend that there's not for so long. Everything changed," said Chlumsky, 29, who struggled to find work as an adult and whose most notable recent credit was a role in 2009's "In the Loop."

"I was career-conscious at 10; it became unavoidable," she said. "... I became very aware of what job I wanted next, and then when the jobs stopped coming, the rejection of it was a lot for a kid to handle."

Sarah Polley, who rose to stardom as a child acting in Terry Gilliam's "The Adventures of Baron Munchausen" and the Disney TV show "Avonlea," thinks the film industry needs to re-evaluate kids' place in Hollywood.

"We've decided as a society that we don't think kids should work, period," she has said. "But for some reason, we make this exception in an industry where there's enormous pressure, long hours and a lot of people who aren't necessarily equipped to be around kids all day."

Polley, 31, has gone on to have a successful career as an actress and director -- her 2007 film "Away From Her," which she wrote and directed, earned two Oscar nominations.

But she admits things might have gone differently.

"There were kids who were a lot more talented than I was who didn't have that lucky break."