Why do we love to give each other presents? Why are business people so keen to buy each other a meal? Why do people hand you free food in the supermarket? And makes us lend things to our friends? The answer is reciprocity. It means that if you do a favor for someone, they feel they must do you a favor in return. Imagine a friend has just cooked a meal for you. You should be happy, but it might also give you a bad feeling that you now owe your friend something in return. So when, at the end of the meal, your friend asks you a favor, you'll find it very difficult to refuse them what they want. Businesspeople use this technique all the time to sell things to people. They offer customers a special deal or promise them a small gift. Of course, they don't tell customers that they need to buy something in return. They don't need to - the feeling that you owe somebody something is strong enough.

In the morning, I usually make myself a cup of coffee. Then, I start checking my emails and send replies to those important ones. I usually have a meeting with my team members every morning. We give one another updates about our individual tasks. After the meeting, I continue with my task. My colleague usually gives me a snack at break time. She likes baking pastries. Before I go home, I send a report to my boss.