If you're an actor, you have to be able to summon naked emotion on cue. If you're a pector, all it really takes is a greasy, freakishly engorged man-rack. Leaving tricky dialogue and technical facial expressions to flat-chested artistes like Jude Law and Leo DiCaprio, pectors simply take off their shirts and lets the beefcake do the heavy lifting. With both Meet the Spartans and Rambo currently chest-thumping the competition at the box office, and the Mattthew McConaughey vehicle Fool's Gold on the way, it's time to give pectors their due with an honorary retrospective.

CLARK GABLE / IT HAPPENED ONE NIGHT (1934)

Ostensible reason for shirtlessness: He's about to get with Claudette Colbert.

Real reason for shirtlessness: Claudette Colbert not allowed to take off her shirt.

Rehearsal/preparation: Removed his training bra?

Cultural repercussions: When America's men find out Gable doesn't wear an undershirt, undershirt sales allegedly drop 75%.

Pector or Actor?: With those flaccid man-buds? Definitely actor. But paved the way for the pectors to come.

BURT LANCASTER / THE SWIMMER (1968)

Ostensible reason for shirtlessness: Like a salmon returning to its spawning ground to die, Burt's headed home, one swimming pool at a time.

Real reason for shirtlessness: Only one way to get people to see depressing art-house flick about crazy broken loser: Put Burt Lancaster in a Speedo the entire film.

Rehearsal/preparation: Incredibly good genes. (Lancaster was 55 when he made this movie.)

Cultural repercussions: 25-year-olds everywhere feel shamefully deficient.

Pector or Actor?: Four Oscar nominations, one win. At 55, he still looks like he could bench-press Kirk Douglas. Pector/actor!

BRUCE LEE / ENTER THE DRAGON (1973)

Ostensible reason for shirtlessness: Strike fear into the hearts of enemies.

Real reason for shirtlessness: Hated doing laundry.

Rehearsal/preparation: Endless one-armed push-ups, using only thumb and forefinger.

Cultural repercussions: Approximately 37% of all contemporary culture influenced by Lee in some way.

Pector or Actor?: If Lancaster proved you could go an entire movie without a shirt, Lee proved you could go an entire career. History's purest pector!

ARNOLD SCHWARZENEGGER / PUMPING IRON 1977

Ostensible reason for shirtlessness: Olympic-sized self-absorption.

Real reason for shirtlessness: Olympic-sized self-absorption.

Rehearsal/preparation: Bench-pressing bar belles all night long.

Cultural repercussions: Ask a Californian.

Pector or Actor?: When people can't understand a word of dialogue you utter until at least your tenth movie, you're definitely a pector!

SYLVESTER STALLONE / FIRST BLOOD II (1985)

Ostensible reason for shirtlessness: Rambo is part-Indian, and part-Indians rarely wear shirts.

Real reason for shirtlessness: It worked in Rocky.

Rehearsal/preparation: Method benching.

Cultural repercussions: Rhinestone.

Pector or Actor?: Name two watchable Stallone movies where he doesn't take off his shirt. Pector!

BRAD PITT / THELMA AND LOUISE (1991)

Ostensible reason for shirtlessness: Ironic feminist eye candy.

Real reason for shirtlessness: Feminist eye candy.

Rehearsal/preparation: Equal parts SoloFlex and waxing.

Cultural repercussions: Depiction of the pector as bait instead of predator foreshadows the era of the metrosexual.

Pector or Actor?: Stuck in C-list limbo until his chiseled abs jump-started career. Packtor, but with actorly ambitions.

ENTIRE CAST / 300 (2007)

Ostensible reason for shirtlessness: Warriors don't sew.

Real reason for shirtlessness: Fanboy projection.

Rehearsal/preparation: Tonight we dine in hell -- on three ounces of very lean turkey and a side order of steamed steroids!

Cultural repercussions: Simultaneously reignites chickenhawk passion for War on Terror and chest implants craze.

Pector or Actor?: We've seen better acting in a Men's Health exercise pictorial. Pectors, prepare for glory!

SYLVESTER STALLONE / RAMBO (2008)

Ostensible reason for shirtlessness: Wait, what the?!? Why is Rambo wearing a shirt?

Real reason for shirtlessness: Apparently, at 62, Sylvester Stallone is no Burt Lancaster.

Rehearsal/preparation: Admits using HGH to bulk up for the role, so why the T-shirt?

Cultural repercussions: Making a pector like Stallone wear a T-shirt is like making a bulldog wear earrings. It doesn't look right, and it's probably immoral.

Pector or Actor?: A few ounces of cotton does not an actor make. Pector for life!

ENTIRE CAST / MEET THE SPARTANS (2008)

Ostensible reason for shirtlessness: Satire.

Real reason for shirtlessness: Much easier to find a few dozen unemployed pectors than one genuinely original comic screenplay.

Rehearsal/preparation: 300 diet.

Cultural repercussions: Strong box office means we'll have to suffer through at least one more crummy movie that randomly spoofs a bunch of other crummy movies.

Pector or Actor?: We've seen better acting in 300. Pectors, prepare for the remainder bin!

MATTHEW MCCONAUGHEY / FOOL'S GOLD

Ostensible reason for shirtlessness: Shirtlessness suggests character's lunk-headed, happy-go-lucky approach to life.

Real reason for shirtlessness: Matthew McConaughey doesn't own any shirts.

Rehearsal/preparation: Flex-offs with Lance and Jake.

Cultural repercussions: McConaughey's professional work has yet to make any measurable cultural impact whatsoever. However, after his infamous shirtless bongo incident, bongo sales allegedly dropped 75%.

Pector or Actor?: Has the pecs to carry a five-sequel action franchise, but apparently not the heart.