Institutions are written in laws, but they run on something harder to write down: the expectation that other people will mostly play fair. A farmer in Valencia waits for her turn at the canal because she expects her neighbors to wait for theirs. A voter accepts defeat because she expects the winners to give up power when they lose. This level examines that expectation, how it grows and how it breaks.

Why some governments work better

In 1970 Italy created new regional governments with the same laws, powers and budgets across the country. The political scientist Robert Putnam and his colleagues followed them for two decades and published the results in Making Democracy Work (1993). Some regions, mostly in the north and center, ran efficient and responsive governments. Others, mostly in the south, struggled. Putnam argued that the difference tracked the density of civic life: choirs, sports clubs, cooperatives and reading of newspapers. He used the term social capital: the networks, norms and trust that let people cooperate for shared ends.

Critics argued that Putnam traced the differences back too far, to medieval history, as if regions were trapped by their past, and that he paid too little attention to economics and to how the Italian state itself treated the south. The debate continues, but the core idea, that cooperation depends on connections among ordinary people, has been widely adopted.

Bowling alone

Putnam later turned to the United States. In Bowling Alone (2000) he documented a decline from the 1960s onward in membership of clubs, unions, churches, parent associations and civic groups. His title came from a striking detail: more Americans were bowling than ever, but fewer were bowling in organized leagues. He blamed television, longer commutes and generational change, among other forces. Critics replied that people had not stopped associating, only changed how, with new kinds of groups and later online communities replacing older ones. Whether online ties can do the same civic work is still debated.

Bonding and bridging

Not all social capital is alike. Bonding ties link people who are similar, while bridging ties link people across group lines. Bonding ties give support and identity, but on their own, bonding ties can turn clannish. Bridging ties are rarer and more fragile, yet they are the ones that hold a diverse society together, because they give people reasons to trust others who are not like them.

Ties that stop riots

The political scientist Ashutosh Varshney tested this idea on one of the gravest questions in South Asia: why Hindu-Muslim riots break out in some Indian cities and not others. In Ethnic Conflict and Civic Life (2002) he compared pairs of cities with similar populations but very different histories of violence. Varshney found that cities with strong civic ties between Hindus and Muslims had far fewer riots. Everyday contact, such as neighbors visiting and children playing together, helped in villages and small towns. In large cities, organized links such as mixed business associations, trade unions and political parties mattered most, because they could squash rumors, police provocations and call peace meetings when tensions rose.

Trusting strangers

People often assume others are less honest than they are. In a study published in 2019, the economist Alain Cohn and colleagues handed in more than 17,000 "lost" wallets at banks, hotels and offices in 355 cities across 40 countries. Some held no money, some a small sum. Most experts asked in advance predicted that money would lower the return rate. Instead, wallets holding money were returned more often than empty ones, in almost every country studied. Many people, it seems, would rather not see themselves as thieves.

Trust is earned

None of this means blind trust is wise. Naive trust invites exploitation, and trust in institutions should depend on how they behave. Countries with high trust between strangers also tend to have low corruption and fairly equal incomes, and the causes run in both directions: fair institutions build trust, and trust makes institutions easier to keep fair.

Worked example: Aligarh and Calicut

Among Varshney's pairs were Aligarh, in Uttar Pradesh in the north, and Calicut, now Kozhikode, on the coast of Kerala in the south. Both had large Muslim minorities of a similar share. Aligarh suffered repeated deadly riots in the decades after independence. Calicut had remarkably little communal violence over the same period.

The difference was not that people in Calicut had no religious identity or that politicians never tried to stir trouble there. It was the density of bridging organizations. Hindu and Muslim traders were tied together in business associations; trade unions, social clubs and party branches had mixed membership. When rumors spread, as they did during national crises, these networks gave local leaders on both sides the means to check facts, calm crowds and keep the peace. In Aligarh, civic life was largely divided along religious lines, so no comparable network existed when a rumor started.

For anyone hoping to build a peaceful society, the lesson is practical. Friendship across lines matters, but so do organizations that give people from different groups a shared stake and a habit of working together before trouble comes.