Rudy and Lizzie were both explorers, and at the Chemistry.com party, investment banker Rudy, with his booming laugh and bonhomie, was a big hit. The quieter Lizzie, who works in the home textile business, said, "He was easy to talk to."
Rudy and Lizzie's first date began with an intimate dinner at an Italian restaurant, but right away they began to find differences, not common ground.
Rudy is into sports, while Lizzie describes herself as a "cultural woman." To Fisher, this was not a good sign. "These are two explorers and two explorers are naturally drawn to each other generally. But they have to have the same interest or want to learn about each other's interests."
But halfway through the date, Lizzie seemed relaxed about how things were going: "He's a cute guy, and you know, we'll see, we'll see. It takes time to really get to know someone."
Tim and Mary, the fourth couple, seemed more at ease on their first date. He's a negotiator who works as a recruiter for a medical market research company; she's a director who works as a tax manager in the mergers and acquisitions field.
Their first date began at an outdoor cafe, and by the time they had taken an evening pottery class, they were laughing heartily and trading zingers.
"Don't you mess with my piece!" Tim jokingly warned Mary, while she teased him about his slow cleanup efforts afterward. "I'll help you out," she said, adding "I don't want to be here all night."
But despite all the laughter, at night's end, reviews of the date were mixed.
"It's just sort of that je ne sais quoi, if you'll excuse the term," Tim said. "It's that unsaid chemistry, umm, that's either there, or it's not, or it's somewhere in between. I think it's somewhere in between."
Tim and Mary never made it beyond that first date, so Tim found another match online with Stephanie, another negotiator. Tim and Stephanie's relationship took off from the start, and five months later was still going strong.
Whether strolling in the park or riding in a pedicab, Tim and Stephanie could barely keep their hands off one another. In both a dark bistro and a trendy restaurant, they engaged in endless "courtship feeding" -- serving one another food and drink.
But Fisher was not convinced that these two negotiators would maintain their relationship in the long term. "What's interesting about two negotiators," said Fisher, "is they can sort of implode."
Five months later, Maggie and Brandon were still together. "20/20" caught up with them when they were clearly having a good time at a rock-climbing lesson, followed by drinks at a dark bar. But as the evening wore on, Brandon's insecurity emerged.
"You kind of intimidate me," he said. "I feel like I'm not smart enough, funny enough."
Fisher said this is not atypical for Brandon's personality type: "They undermine themselves -- negotiators do."
After 10 dates, Maggie called it quits. For her, it was another failure that underscored the complexity of love. "I want someone who I can be with," she said, "but I don't know how to find it."
After several months of dating, Jason and Nacole also ended their relationship, but on a happier note. "I don't think there was anything I didn't like about her, "Jason said.
Nacole echoed that sentiment: "I really couldn't think of anything that I really didn't like about Jason. … we, you know, just worked in different areas of the world."