Do you prefer to have a few close friends or a larger social circle that is less deep? Social psychologists say your preference reflect your personality but also individual circumstances - like socioeconomic conditions.

Social psycholosits Shigehiro Oishi of the University of Virginia and Selin Kesebir of the London Business School say that Americans may prefer a large social network, for example, because Americans move around a lot. Thus, it may make sense to spread time and resources across many friends to minimize the loss of any one friend moving away. Economic conditions at a given time are also a factor. When times are prosperous, they speculate, your friends are less likely to need much help, whether it's covering a hospital bill or providing babysitting, and so a broad network of friends is easy to maintain. But when times aren't as flush, having more friends might incur huge costs in terms of both time and resources.

"In the age of Facebook, many Americans seem to opt for a broad, shallow networking strategy. Yet, cross-cultural research has shown that having many friends is not always viewed positively outside the United States," Oishi and Kesebir write.

With that predetermined result needing validation, Oishi and Kesebir predicted that a broad, shallow networking strategy would be optimal for people living in a residentially mobile, economically favorable context. A narrow, deep networking strategy, on the other hand, would be optimal if people tend to stay in one place and economic conditions aren't as favorable.  So they made the kind of quality computer model social psychologists tend to make and then did some surveys.

Their numerical model simulated the benefits individuals receive from their social network under various socioeconomic conditions. It was as subjective and variable as you might expect. Then they simulated people who have different numbers of friends at different levels of friendship and they were also able to account for the investment required by each type of friendship.

As they predicted, they found that having a small social network with deep ties to friends is advantageous when friends are not likely to move away and the economy is unstable. Regardless of economic conditions, having a broad social network with weak ties to friends is advantageous when friends are likely to move away.

Then they set out to investigate whether this pattern of results would hold up in the real world - which is to say, the world of online survey takers. They recruited 247 Americans to participate in an online survey through Amazon's Mechanical Turk. The survey was designed to parallel their computer simulation. The participants were asked to list three different kinds of friends: very close, close, and distant. In order to get a sense of the participants' social networking strategy, the researchers asked them to imagine that their time, energy, and money were limited to 60 points and to distribute the points among their three types of friends.

They also claim to have assessed participants' subjective well-being through a combination of three measures: life satisfaction, experiences of positive emotions, and lack of experiences of negative emotions. If only it worked that way, you could save a lot of money on therapy bills.

Finally, the researchers used census data to obtain information about residential mobility and median family income in each zip code.

The findings from the survey matched the computer prediction which matched their predetermined belief about Americans. In zip codes that were residentially stable and relatively low income, participants who had a narrow, deep friendship strategy reported greater well-being than those who had a broad, shallow friendship strategy. Notably, the broad, shallow strategy was associated with subjective well-being in all three of the other economic conditions (low income-unstable, high income-stable, high income-unstable).

Oishi and Kesebir argue that these results provide clear evidence for the role of socioeconomic factors — such as residential mobility and economic security — in determining the most adaptive networking strategy.

"As residential mobility decreases and economic recession deepens in the United States, the optimal social-networking strategy might shift from the broad but shallow to the narrow but deep, even in a nation known best for the strength of weak ties," the researchers conclude.

Published in Psychological Science.