First Born
Newscasters and TV talk show hosts tend to be first born or only children. Prominent examples include: Walter Cronkite, Peter Jennings, Dan Rather, Ted Koppel, Oprah, Donahue, Geraldo, Arsenio Hall and Rush Limbaugh. Over half of U.S presidents were firstborns. Clearly, firstborns are natural leaders. They also tend to be reliable, conscientious and perfectionists who don't like surprises. Although, firstborns are typically aggressive, many are also compliant people pleasers. They are model children who have a strong need for approval from anyone in charge.
The bolded bits are true for me personally.
Idk about the natural leader thing. I like to be in control of things that are relevant to me, and I do prefer a leadership position to a less responsible one in general... but it totally depends on the context. I think it has more to do with the fact that I don't trust other people with things that are important to me, rather than a natural urge to be a leader, because I'm quite happy to take a back seat with things I know nothing about or don't percieve as my responsibility.
Anyway I'm pretty sure most of us fit into some part of each category anyway so it's probably a bullshit theory *shrug*