Social norms are the implicit social rules that govern behavior within a community. Norms are not directly established; instead, they develop over time as people go about their daily behaviors, sense people's reactions to those behaviors, and observe what other people are doing. Social norms differ, depending on the group of people, community, or culture. What is considered fully normal, even admirable, in one group may be met with disapproval in another (e.g., offices where casual dress is normal vs. offices where everyone must wear a suit). According to psychologist Robert Cialdini, people are constantly looking for "social proof" to guide their own behavior. They look for clues to what other people are doing in order to understand the appropriate behavior in a given situation. Social proof of what is acceptable is a particularly powerful guide to behavior when the situation is ambiguous or new. In relation to social norms, one of the big challenges we face is creating a sustainable culture where so many unsustainable actions are considered perfectly normal and even something to strive for: driving alone, living in a very large home, eating foods that have traveled long distances, eating meat at every meal, having a weed-free green grass lawn, and continuously shopping for new consumer goods. Sustainable behaviors, such as buying second hand or taking short showers, on the other hand, are often seen as lower or undesirable in status. Social norms create opportunities for change; for one thing, they are dynamic and constantly shifting (just think about fashion trends). The goal for those of us who want to bring about a more sustainable society is to quickly bring sustainable behaviors into the realm of normal, acceptable one, and something people aspire to. How do we accomplish this? We need to give people evidence, social proof, that sustainable behavior is acceptable and desirable. (Adapted from: https://www.pca.state.mn.us/sites/ default/files/ p-ee1-01.pdf)The passage is mainly concerned with ….