The take away: Loosening these tight group boundaries means that people's next-door neighbors may have different jobs or levels of education, but they may stil

The take away: Loosening these tight group boundaries means that people's next-door neighbors may have different jobs or levels of education, but they may still have similar politics or recreational activities. These similarities allow people in different social groups to encourage the adoption of a new complex idea, take neighborhood recycling as an example, which can then spread to other neighborhoods and social groups. But when group boundaries are eliminated entirely, people have almost nothing in common with their neighbors and therefore very little influence over one another, making it impossible to spread complex ideas.