Hundreds of millions of people live and work while using a language that is not their native tongue. Given that using a foreign language is more difficult than using a native tongue, one would expect an overall deleterious effect on their mental and physical performance. We have discovered that the opposite is often true. We argue that a foreign language provides psychological and emotional distance, thereby allowing people to be less biased in their decision-making, more willing to take smart risks and to be guided more by hope than by fear of loss. We show that a foreign language also affects ethical behavior such as cheating and moral choice. But we also find that when emotions are crucial for learning from experience, native tongue is crucial for improving choice over time. Living and functioning in a foreign tongue, then, has surprising consequences for how individuals think, feel and operate, and it has important implications for social policy, negotiation, diplomacy and immigration issues.