Being an only child, I am very absorbed with myself. Not in a selfish way, but in a contemplative, reserved way. I think this is  a trait that is probably pretty common among only children because growing up we spend so much time alone and we are our parents’ only concern, so we inherently receive a lot of attention and support. Therefore, only children tend to think about themselves a lot because that is how they are brought up. This tendency can result in a negative self-absorption and selfishness where one only thinks about oneself at the cost of others. But it can also result in a very contemplative and almost nervous concern for one’s life and future, i.e. what do I want to do in life, am I doing the right thing/making the right decision, what kind of people do I want in my life, what kind of person do I want to be, etc. This is not to say that people who have siblings do not have the same concerns, but there is something about only children and the time they spend alone and the way they are brought up, that I think fosters this kind of thought.