Interest Groups – clubs for hobbyists, sport leagues, golf clubs, book reading clubs, etc. Cities contribute to the emergence of these groups due to population concentration that allows finding niche interests groups forming. Georg Simmel believed that urban lifestyle makes people indifferent to the environment, meaning that more importance goes to the choice of voluntary groups in the city. Robert Putnam, in his “Bowling Alone”, mentioned the decline of social clubs in modern urban life and the escalating debate whether the trend continues today by going online. Source(s), Link(s), Inspritation(s) and Further Reading:Social Groups: The ConceptClassification of Social Groups