Sean Patrick Astin was born in Santa Monica, CA. His biological father was Michael Tell, to whom actress Patty Duke was married to for only a month in 1970; he was later adopted at age three by actor John Astin. The child grew up considering both men to be his father. At the time of his birth, however, there were rampant tabloid rumors that his real father was Desi Arnaz, Jr., who famously dated his mother, but this was later proven false. Astin was the older half-brother of Mackenzie Astin who would also become an actor. Sean went on to attend St. Paul the Apostle Elementary School and the Crossroads High School for the Arts in Los Angeles. He later received degrees with honors in History and English from UCLA. At age nine, Astin starred alongside his mother in the ABC after-school television special "Please Don't Hit Me, Mom" (1981) about a child physically abused by his mother. Life at home with his bipolar mother also proved challenging for the actor. Astin recalled that their life was severely impacted by Duke's mood swings, during which she would scream, throw things, and once drove her car into the garage through the door. His experience with Duke inspired Astin's involvement with educating the public about identifying and treating mental disorders later in his career. His work as an advocate for bipolar disorder also earned him another fan base. Strangers often stopped him on the streets to talk about his mother and their family's experience with the disease. Duke was fully supportive of his work promoting the disease.Four years after his television debut, Astin made a huge leap to the big screen, starring as lead in the Steven Spielberg-penned and Richard Donner-directed adventure flick, "The Goonies." The story of a group of kids - including Corey Feldman, Martha Plimpton and Josh Brolin - who search for a lost pirate treasure to save their homes from a real estate developer became one of the most beloved films of the 1980s and a cultural touchstone for Generation-X. The actor - who turned in the one earnest, touching performance in the film - later claimed that he was able to keep the treasure map from the film as a souvenir, but his mother accidentally discarded it years later.In 1987, Astin played opposite another teen idol, Kirk Cameron, in the role reversal comedy, "Like Father, Like Son" (1987). The actor started taking on more mature roles by the late 1980s and early 1990s, starting with an appearance in "The War of the Roses" (1989), followed by the World War II drama "Memphis Belle" (1990). A year later, Astin costarred with Lou Gossett, Jr. in the thrilling "Toy Soldiers" (1991), about a group of boarding school students who fight to survive against terrorists. Though he would not know it at the time, playing the title role in 1993's "Rudy" became Astin's most identifiable and inspiring character. In the film, Rudy's childhood dream of playing for Notre Dame seemed destined for failure. His blue-collar family scoffs at his aspirations, telling him he is too small in stature to become a football player. In rebuttal, Rudy goes to hilarious and heroic lengths to gain admission into the coveted university but once there, becomes a walk-on player. Rudy ultimately wins the respect of his coach and his teammates, who give him one shot at glory. Since its release, the film's message of perseverance won and continued to win the hearts of generations of filmgoers.A stream of steady roles kept Astin in the limelight, including the hilarious buddy film "Encino Man" (1992), in which he played the straight-laced Dave to comedian Pauly Shore's Stoney. He displayed his true versatility in several film projects that were less commercial but held more depth. He was a runaway living in Los Angeles in the gritty urban drama "Where the Day Takes You" (1992), and one of Susan Sarandon's seven sons in "Safe Passage" (1994). Astin also appeared in the military drama "Courage Under Fire" (1996) with Denzel Washington and Meg Ryan, and in 1998's "Bulworth" with Warren Beatty and Halle Berry. Acting in heavy dramas and political satires with acting heavyweights did not lessen Astin's appreciation for pure comedy. He returned to the genre in 2003 as Doug, the weight-lifting obsessed brother of Lucy (Drew Barrymore) in the romantic comedy "50 First Dates." Astin also appeared with Adam Sandler in the comedy, "Click" (2006). In 2001, Astin was cast as one of three Hobbit sidekicks role in the epic trilogy, "The Lord of the Rings: The Fellowship of the Ring" (2001). As Samwise Gamgee, Astin was lead character Frodo's (Elijah Wood) closest friend who went on several perilous adventures to protect his best friend and the Ring. Director Peter Jackson reportedly advised Astin to gain about 40 pounds prior to filming because according to Jackson, "hobbits are very portly." Again displaying a heartbreaking honesty onscreen, Astin was a cast standout in an impressive lineup that included Viggo Mortensen, Ian McKellen and Cate Blanchett. In fact, his cast mates would repeatedly remark during press junkets that he was Samwise Gamgee. Filming the trilogy in the treacherous "Middle Earth" proved to be more physical than the actor expected. While filming the "Lord of the Rings: The Fellowship of the Ring" (2001), Astin stepped on a piece of glass during a scene in a lake and had to be rushed to the hospital where he received many stitches to repair the injury. Filming the third and final installment, "The Lord of the Rings: The Return of the King" (2003), became an emotional experience for the entire cast, as they had filmed all three back-to-back in New Zealand and has become a sort of family. He cried when he saw the last three reels of the movie: "It was all of the tension and stress and pressure of having a wife and children, having a career, the investment of these movies. I could barely breathe, and the movie facilitated that. It was just a huge release."Astin worked behind the camera later in his career, directing and co-producing the Academy Award-nominated short film "Kangaroo Court" (1994) with his wife, Christine, whom he married on July 11, 1992. The two were partners in every sense of the word, with three daughters: Alexandra, Elizabeth and Isabella, and their own production company, Lava Entertainment. His 2003 short film "The Long and Short of It" was written and produced in New Zealand during filming of "LOTR," with help from director Peter Jackson and his cast mates. The film was included as a bonus feature on "The Lord of the Rings: The Two Towers" (2002) DVD. Astin also branched out into meatier television roles, acting in the 2005 miniseries "Into The West" (TNT) that reunited him with his "Goonies" brother Josh Brolin, as well as appearances on "Law & Order" (NBC, 1990-2010), "Monk" (USA, 2002-09), and "My Name Is Earl" (NBC, 2005-09). Astin also joined the cast of "24" in 2006 (FOX, 2001-2010) as the smart, smug CTU administrator Lynn McGill for 10 episodes. Unfortunately, his character died saving others from nerve gas poisoning on the show. In 2009, the actor appeared in the comedic films "Demoted" with Michael Vartan, and "Stay Cool" with Wynona Ryder.