When and why do we trust other people? Do we trust someone only if abused trust has insignificant consequences? Do we base the decision to trust someone on that person's looks? Are males more likely to trust other people than females? Trust facilitates both social and economic life as it eases the burden of unspecified reciprocation. However, trust is risky: unjustified trust might lead to undesirable consequences. This book adresses the way in which people balance the cost and benefits of trusting and the way in which commitments may enhance trust. Using a simple game as a metaphor for trust, theoretical predictions are derived and confronted with the behavior of people in an experimental setting.