Think of your family or friends. How well would those relationships work without trust -- or with a broken trust?

Tiger Woods considers a difficult shot from deep grass during the 2009 U.S. Open

The Associated Press just voted him "athlete of the decade." But more than half the votes arrived before his private life hit the news.

The young golfer has admitted being unfaithful to his wife and family. Public opinion of him has fallen. Some companies have removed him from their advertising. Tiger Woods is now taking what he calls "an indefinite break from professional golf."

Trust also plays into much bigger issues, like reaching a climate change agreement or reforming a health care system.

Two different researchers have recently studied the effects of trust within countries.

Pelle Ahlerup is an economics researcher at Sweden's University of Gothenburg. His research suggests that trust between people is more important in countries with a weak legal system. And in societies where there is less trust between people, the quality of the legal system plays a larger part.

He says projects designed to increase interpersonal trust can have a major effect in poor countries with undependable legal systems. Earlier research has shown that countries with greater trust between people generally do better in economic growth and other areas.

What about trust in government -- could it even affect murder rates? A historian at Ohio State University argues yes in a new book called "American Homicide."

Randolph Roth studied homicide rates over the past four hundred years in parts of the United States and western Europe. The Justice Department says rates in recent years fell to levels last seen in the middle of the nineteen sixties. Still, murder rates in the United States have generally been among the highest among Western democracies since the middle of the nineteenth century.

Professor Roth says poverty and unemployment do not lead to higher murder rates. Nor do stronger punishments and more police keep murder rates down.

He looked at murder among unrelated adults and found four things that relate to homicide rates. One is a belief that a government is stable and that the justice and legal systems are fair and effective. Another is a feeling of trust in government officials.

The third factor is a sense of pride in country and unity with other citizens. And the fourth is a belief that a person's position in society is satisfactory and that getting respect does not require violence.

When these feelings are strong, he says, murder rates are generally low. Rates are higher when people do not trust their leaders or feel protected or connected to society. But Professor Roth says even the best political leaders cannot unite a country once a society's problems get out of control.

And that's IN THE NEWS in VOA Special English, written by Brianna Blake. I'm Steve Ember.