How can you increase your chances of having a child that grows up to be successful?  The answer according to a study is just have one.  An only-child is likely to grow up and earn six figures. had some other interesting findings in a new survey.  Single children may earn more, but those from families of more than one child are generally more satisfied with their jobs.
Why are those from families of one child more successful?  Perhaps an only-child is forced to play alone enough that he or she is forced to be creative --  there's no one around to tell them an idea is a bad one so they forge ahead.
There are some very interesting notes here about how your astrological sign relates to your success at work.  An only child is not only more likely to earn six figures, but is also more likely to hold a top management position like CEO or senior VP.

Among workers with siblings, a first born child is the most likely to earn six figures and hold a top position while a last born child is most likely to work in middle management.  A middle child is most likely to report holding an entry-level position and earning less than $35,000.

An only child is drawn toward working in technical and health-related fields and protective services.

A first born tends to be attracted to government positions and science, while middle children lean toward public service and care-taking roles. The youngest in families prefer more creative roles and technology.

Virgo, Aries and Scorpio signs are the most likely to earn six figures.

Capricorn and Leo signs are the most likely to hold an upper management position.

An Aries is most likely to work in middle management and an Aquarius is the most likely to hold an entry-level job.

Virgo, Libra and Taurus signs are the most likely to report being satisfied in their jobs.

(If you're a Virgo that's an only child, the world is yours!)