Trisha Prabhu. Trisha Prabhu / Google Trisha Prabhu, a 13-year-old from Chicago, won a spot as one of Google's 15 Global Science Fair finalists for her project about stopping cyberbullying by making teens and tweens think before posting hurtful comments.

The science behind Prabhu's idea is simple: Teens are impulsive and, because of their brain structure, more likely to post hurtful messages without pausing to think about the consequences.

The prefrontal cortex — the part of the brain responsible for self-control that helps people think before acting — isn't fully developed until age 25. Her theory is that if teens are forced to take a moment of reflection before posting a mean comment, they won't do it.

She created a system to test her hypothesis called Rethink, which prompted students who said they would post a mean comment to think about how it might affect its target before posting it. Turns out, in 93.43% of her 533 trials, the student decided not to post the comment.

Now that she has successfully tested her hypothesis, Prabhu wants to create a real product that could work with social media sites and apps that would filter messages that were potentially mean or hurtful, and alert senders to take an extra second to think before posting.

"I am looking forward to a future where we have conquered cyber-bullying!" she writes in her project's description.

Prabhu is one of 18 incredibly intelligent teenagers who made it to this year's finals. Google will announce the top project in September, and the winner gets a 10-day trip to the Galapagos Islands, a visit to the Virgin Galactic Spaceport, and $50,000 in scholarship funding.