"Chemically, it's a very good match," Fisher said. "But we also have to deal with their upbringing, their ambitions, their interests."
Fisher watched as cameras rolled on Lizzie and Rudy's date at a rowdy quiz night at a local bar.
"She's turning away from him," Fisher said of Lizzie. "When you turn the shoulder away and the head away, it's not good."
After 45 minutes, Lizzie asked to go home. Rudy seemed dejected, but Fisher predicted he would bounce back.
"Explorers are flexible," she said. "Rudy will go on to somebody else who is more charming and charismatic and works for him. And it'll be an explorer."
All of the people "20/20" followed remain hopeful that they will eventually find a life partner. And despite years of study, Fisher says that the science of seduction is still evolving.
"If everybody could match people easily, we wouldn't have been talking about romantic love for the last 4 million years."