In law, many systems have incorporated the concept of primogeniture, wherein the firstborn child inherits their parent's property.
He argued that birth order can leave an indelible impression on an individual's style of life, which is one's habitual way of dealing with the tasks of friendship, love, and work.
When conducting these studies, parents are interviewed and give examples on the type of personality each child expresses.
When examining answers from organized studies, personality and attitude traits are repeated when comparing different children born into the same birth order.
When studying famous and historic geniuses in the artistic field, recurrence has demonstrated firstborns to be the children with a creative side as well as being the productive ones.
This study was related to the U.S presidents when it was discovered that more than half were firstborn, the rest were middle and four were lastborn.