I decided to research further whether birth order within a family actually has effect on personality or behavior. It has long been believed that the first born in a family tend to achieve more, middle borns tend towards diplomacy, and later borns tend to take more risks. However, when I did more research, I found that most of these claims were exaggerated.
I read the article "How Birth Order Affects Your Personality" by Joshua K. Hartshorne on ScientificAmerican.com. To first address the claim that first borns tend to achieve more, he gave the widely used evidence that 21 of the first 23 astronauts were first borns. He digs deeper on this fact, actually finding that birth order only really creates personality differences among siblings in they are from a very large family. 21 of the first 23 astronauts may have been born first, but, for example, coming from a small family where there are only two kids, those astronauts had a 50% chance to be born first, whereas a child from a five kid family has only a 20% chance to be born first. Family size also affects personalities because of how the resources of the parents must be spread out. More children means more resources need to be used, and each child may not receive the same benefits that children with only one sibling receive.
Personality has less to do with birth order, and more often can be attributed to family size.
That is very interesting that personality is not correlated with birth order which was believed previously. But in retrospect it makes sense that a child's personality is heavily dependent on how much of the parents resources it receives. Children who do not get the attention they need as a child can develop psychological issues that can harm the child for the rest of their life. A famous story about a boy who became a sociopath starts out by talking about how the child was taken care of and touched inconsistently. The child would cry and the mother would come every once in a long while. When the boy was in his teenage years he killed two girls horrifically and had absolutely no remorse. He had no concept of emotions. His mother did not show him emotions so he was never able to develop them properly.