At the end of the nine weeks, partners who had rated each other positively had the strongest friendships, thus establishing the predictability of that first encounter. That was reinforced by the fact that the students acted accordingly, for example, sitting closer together during class, and communicating with each other more frequently.
And it didn't matter if that first encounter was three, six or 10 minutes.
"The effect was as strong after the three minute conversation as it was after the 10," Sunnafrank says. "It could even be happening on first glance."
"That tells you things are happening very quickly," adds Ramirez. "People are making snap judgments about what kind of relationship they want with the person they just met."
But the strongest effect of all was a negative one.
"It's the person who has the lower assessment of the potential for the relationship that has the strongest effect," Sunnafrank says.
"If I decide you're not really someone I want to get to know, I'm going to restrict my conversation with you, even at the very beginning," he says. "I'm going to look away, I'm not going to seek you out when I come into the classroom. So I'm giving you signs that I'm not interested, which is going to make you uninterested in me. And you're going to act in the way I predicted, which is not positive.
"If I'm not interested in you, I'm eventually going to prevail."
But what works for college freshmen may not work for the rest of us. Sunnafrank notes that freshmen tend to be aggressive in the pursuit of new friendships, and that changes over time, at least for most of us.
"In most situations in life, our time is pretty much claimed by work and family matters, so even when you meet people you really like, chances are not much is going to happen. As life goes on and social networks become solidified, acting on that first impression becomes less likely," he says.
And as they say, nothing lasts forever. We all know people we disliked in the beginning, but learned to like as we got to know them, and vice versa. So relationships are not always predictable, regardless of how strong that first impression may have been.
"Surprising events," as Sunnafrank calls them, can change a relationship in a hurry. "If you stab someone in the back …"
That reminds me of a very elegant lady who taught my English lit class in college. A student complained one day about something we had read in which love had turned to hate. How could that be possible?
"Oh, Miss Evans," the professor said, always as polite as she was eloquent, "don't you know the line that divides love from hate is a very fine line indeed."
Lee Dye’s column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.