Gattaca's genetic discrimination only functions because the film treats DNA like a credit score: legible, unchanging, determinative.

But genetics isn't a database — it's a probabilistic mess constantly reinterpreted by environment, gene expression, epigenetics, and mechanisms we're still discovering.

The film's architects didn't know this yet. We do now, which means Gattaca predicted the actual threat backward.

The danger isn't that genetic tests will become too accurate—it's that they're already inaccurate enough to justify exclusion while appearing scientific. A polygenic score that predicts 2% of disease variance still gets used to deny insurance, and a genetic marker linked weakly to behavior still determines parole decisions. Vincent's 99th percentile for heart disease is the plot's hinge, but modern genetic counseling would call that number misleading—the test cannot tell you Vincent will have a heart attack.

What Gattaca actually shows, without intending to, is how institutions use the appearance of genetic data to automate discrimination that was already happening—just now with the implicit authority of science. The film got the surface right and the mechanism entirely wrong, which makes it more useful as a diagnostic than as a warning.