One of the most powerful predictors of whether any two people will be attracted to each other is proximity. It seems so obvious that we often overlook it. Or perhaps we overlook it because it doesn’t seem very romantic. But the fact remains that one of the best predictors of attraction is sheer proximity or physical nearness.Of course, new technologies allow us to communicate and interact with others over great distances. Internet dating also means that it’s becoming more common to find lovers and sexual partners from a distance. Yet, the vast majority of our most important social interactions—and this includes romantic attraction—occurs with people who are in the same place at the same time.MORE: Is Your Mate Hotter Than You?For example, back in 1932, James Bossard examined a marriage registry in Philadelphia and found that one-sixth of about 5,000 married couples lived one block from each other before they were married. One-third lived within five or less blocks from each before marriage.More recent studies in the UK have reached similar conclusions. In the late 1970s, for example, about half of marriages that were examined in one study took place between individuals who lived, on average, five kilometers from each other before marriage. Another study found that 25 percent of couples in Reading (a town in southeast England) were born less than 10 kilometers apart, and 50 percent lived within five kilometers from each other when they met.In short, most studies consistently find that the number of marriages declines as the distance between potential spouses increases. Or as Bossard put it, “Cupid may have wings, but apparently they are not adapted for long flights.”The obvious objection to these studies is that new technologies have made such findings obsolete. In fact, even more recent studies indicate that the majority of relationships form between individuals who are in close proximity to each other. One 2006 survey of couples showed that almost a half met at school or work, while most of the rest met in the same neighborhood, place of worship or gym.MORE: Do We Choose Partners Similar to Us? By Dr. SwamiCollege accommodation offers a useful place to examine the effects of proximity on attraction. In one classic study, Leon Festinger and his colleagues studied the way in which students in college housing became friends. They reported that students were more likely to become friends with residents of nearby apartments than with those living further away. More recent studies have similarly shown that college students tend to date others who live nearby.But why does proximity have an effect on attraction and relationship formation? The most obvious answer is that proximity increases the chances of unplanned social encounters between strangers and acquaintances. People who live nearby often attend the same schools, shop in the same stores, frequent the same gym, and so on, all of which increases opportunities for meeting and interacting.In turn, interaction enables individuals to explore their similarities (another important factor influencing attraction, as we’ll see in a future column) and to perceive themselves as part of the same “social unit.” By reducing the functional distance between two individuals, we increase the likelihood that they’ll interact more frequently and find things in common.Conversely, bridging geographical distance requires time, energy and investment. Of course, these issues would’ve been more important in times gone by (when traveling to another country or state required lots of planning and possibly weeks of hard travel conditions) but they continue to exert an influence on relationship formation even today. Some researchers have discussed the concept of “information fields,” the spatial distribution of knowledge that an individual has about their world.MORE: How Scent Influences Attraction Our information fields decay with increasing distance; that is, we have the most information about locations with which we have regular, day-to-day contact. Information fields are, in turn, associated with social circles, the group of people with whom we have the most regular contact. As this concept suggests, we’re most likely to form relationships with people who fall within our information fields generally and social circles specifically.Third, social and cultural groups tend to be geographically clustered: we tend to live among people who are socially and culturally similar to ourselves. To the extent that we like people who are similar to us (remember the future column!), we will likely be attracted to others who live near us.Is there more to it than this? Consider Festinger’s study of college accommodation: while the researchers found that students liked those who lived next door best, those who live just a few doors away can hardly be thought of as living at an inconvenient distance. In addition, those who live nearby could just as easily turn out to be enemies as friends.In my next column, I’ll discuss the psychological reasons why proximity seems to breed affection more than it does animosity. This will include one of my favorite research findings from psychology: the curious case of mere exposure. Stay tuned!QUIZ: What’s Your Relationship Style?