Like God, the secret to making a period film is in the details, in choosing , the right cultural landmarks to evoke a particular zeitgeist. Here's how This Boy's Life captured the 1950s, how Jack the Bear captured the 1970s and how a movie made in the future might capture the Generation-X lifestyle of the 1990s:
SCHOOL LIFE
'50s: Toby confronted by school principal for
scraping obscenity on wall; principal not addressed by name. '70s: Jack confronted by teacher for not expressing bottled-up feelings;
teacher addressed as ''Vince.'' '90s: X-er confronts home-ec teacher for not separating cans and
bottles; teacher addressed as ''Dude.''
HAIR
'50s: Toby meets mother's boyfriend; mother sports
Monroe-esque hairdo, Toby a DA, and her boyfriend a flattop. '70s: Dad meets Jack's girlfriend; Dad has long sideburns, Jack has mop
top, girlfriend has straight hair. '90s: Father's mistress becomes
X-er's girlfriend; trio goes on Sally Jessy Raphael. Father has hair
plugs, X-er has long sideburns, mistress is bald.
MOOD MUSIC
'50s: Toby's friend kisses him while they sit at
piano; duo sings Fats Domino's 1957 tune ''Blue Monday.'' '70s: Jack
kisses girlfriend goodnight; soundtrack blasts Percy Sledge's 1966
hit ''When a Man Loves a Woman.'' '90s: X-er kisses phone receiver
after dialing 900 line; plays tape of Mudhoney's ''Touch Me I'm Sick.''
DECOR
'50s: Toby beaten by stepfather in his room; Boy's Life on
wall. '70s: Jack mourns dead mother in his room; '60s peace poster on
wall. '90s: X-er plays Sega in his room, ignoring parents; 90210 poster on wall.
WHEELS
'50s: Toby drives family car into a ditch; car is a
two-toned Buick. '70s: Jack and father race to hospital in family
car; car is a rust-brown Plymouth Valiant. '90s: X-er shot at while
driving family car on freeway; car is a silver Saturn.

