The Born Sexy Yesterday Trope

Born Sexy Yesterday: A sexual fantasy, created by men for men, usually in Sci-Fi and Fantasy. Features adult female characters that exude sex appeal, but, in other ways, display the intelligence and innocence of a young child.

Born Sexy Yesterday characters are:
Often aliens, algorithms, robots, and mermaids
Naïve and dependent on the male character to guide them
Skilled at something the men value such as combat or technology
Fulfillment of the male fantasy of a virgin woman

The trope is based on a gender power imbalance rooted in male insecurity around evolved women. It attempts to denigrate women by intimating their worth is centered on how they look and how they support men.

The opposite of this trope is rare because women are less likely to need or be attracted to adolescent-acting men.

Examples include:
Splash — Madison
Star Trek — numerous characters
How to Talk to Girls at Parties — Zan
The Fifth Element — Leeloo
Enchanted — Giselle
My Stepmother is an Alien — Celeste
Tron: Legacy — Quorra
The Little Mermaid — Ariel

Next time you watch Sci-Fi or Fantasy, look for this trope!