Dutch sociologist Gerald Mollenhorst has been investigating people's networks of friends and how they change over time. He followed 604 people, between 18-65, over seven years, asking them about their social networks; who they talked to about their problems, who they asked for help with D.I.Y., who they socialized with etc. The study found that the social context in which we meet people plays a big role in choosing our partners, friends and acquaintances i.e. we are as likely to make friends with people because they are close at hand as for any other reason. The study found that people often picked friends from a context where they had already made other friends and that the extent to which our friends know each other strongly depends on the context in which people meet each other. The size of people's networks stayed remarkably stable over the seven years of the study but there was a higher-than-expected turnover. Only 30% of the 'discussion partners' and 'practical helpers' still held the same position in people's networks seven years later and only 48% of people in people's social networks at the start of the study were still in them at the end.
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