Imagine that you are an animal roaming somewhere around greenery part of india. you take any days most of the decision will have instant impact. 

Your genes plays a vital role in shaping your habits. Your genes play a crucial part in or influence everything i.e how much time you spend watching television and getting married to someone or getting divorced to with your wife and your genes also influences how you get addicted to alcohol and cigarettes. Your genes also plays vital role in how patiently you handle any situation or how rebellious you are. How you react to stressful situation whether you are vulnerable or resistant to tense situations your genes also play role in creating or controlling a situation rather than just responding to it after it has happened. Even how interestingly you watch a concert or get bored. If someone is extrovert who loves talking and love to spend time socially can be traced since the birth. for instance when a baby is born then one doctor made a loud noise on table then there are few babies who are reactive toward the sound and there are other babies who didn't respond to the noise. Then doctors track the growth of that baby and when the baby grows they found that the baby who was more reactive at the time of birth are the ones who became extrovert in the future similary baby who didn't react at the time of birth were the introverts when they are fully grown. A person who shows agreeableness it is a trait that describes a person ability to put others need before their own. These person are feel emotion to other pain and so they feel empathetic to others pain and so they try to help them and easily get along with other people. These people are very kind in nature and they handle any situation peacefuly due to which they are admired by everyone due to their agreeable ness they so they have high oxytocin level, a person having high oxytocin level believes in human nature and are generally believe in trusting others due to natural flow of oxytocin they have tendency to handle any problem with much ease as due to this oxytocin they are also very silent and they don't feel depressed easily therefore oxytocin act as antidepressant. These people are so good in writing thank you notes.