Grace Patricia Kelly was born in Philadelphia, to a family of Irish and German origin, on November 12, 1929. She was named after her father's sister who died as a child.
Her father - John Brendan "Jack" Kelly - was a successful businessman and triple Olympic rowing champion. He won two gold medals at the 1920 Olympics and another at the 1924 games.
The term "sibling rivalry" was coined by David Levy in 1937 in relation to the common aggressive response of an older sibling to a new baby in the family. It is also used to describe competition or antagonism between children of the same parents.
It has various causes. Freud thought it was connected to the Oedipus complex whereby sibling brothers would compete for their mother's love, or between sisters for their father's attention.
Kyla Boyse from the University of Michigan suggests it stems from a child's need to define himself or herself as an individual and to separate from a sibling.
Alfred Adler proposes that sibling rivalry is based on siblings "striving for significance" within their family.
Most psychologists believe that it stems from an innate desire to attain parental attention achieved through competing with the sibling.
Whatever the cause, the manifestation can be ugly.
Which national teams - of our varied heritages - are those we roots for at major events, such as the Olympics? And, of course, why do we cheer so loudly for our national teams during the Olympics?
Experts at the University of Texas, Dallas offer several explanations of how we define ourselves via membership in a larger group, sometimes called “collective identity.”
UTD Researcher Dr. Karen Huxtable-Jester says this tendency is stronger in men than women, but everyone seems to enjoy cheering for their national team. She teaches psychology in The University of Texas at Dallas’ School of Behavioral and Brain Sciences.
Another impetus for this is that people like to associate with successful people. Researchers call this BIRG (basking in reflected glory).
The opening ceremonies of the 2012 Olympics - the Games of the XXX Olympiad - begin tonight in London.
The largest international sporting event in the world takes place every four years; it is the third time that it has been held in London. The last time was in 1948.
The first modern edition of the games was organized by the International Olympic Committee (IOC) in Athens in 1896. The original Olympics - with nude athletes - took place in ancient Olympia, Greece, from the 8th century BC to the 4th century AD.
The Olympics is an historical event enjoyed for generations. Participating - as a competitor or spectator - connects you to your ancestors who also lived through the moment.
We've trawled the Internet to find weird and wonderful historic Olympic facts. Here are some of them:
Following our series of polls on characteristics that run in the family, and with the Olympics now underway, we wanted to ask your thoughts on whether athletic ability runs in your family.
Some families love going on hikes, swimming, bike rides and pursuing other outdoor activities together. But do athletic parents produce athletic kids? Do you have athletes in your family?
Let us know via the poll below:
In about three weeks, the 2012 Summer Olympics (officially the Games of the XXX Olympiad) will begin in London, UK.
The countdown to this summer's event began at the closing ceremony of the 2008 summer Olympics in China, as the Olympic flag was handed to the Mayor of London by the Mayor of Beijing.
This year, 197 countries will participate in 26 sports at the biggest international sporting event of the year.
The Olympics provide an opportunity to reminisce about great moments of the past, such as the 1936 Berlin games when Jesse Owens won four gold medals or when Michael Johnson smashed both the 400m and 200m sprints in the 1996 Atlanta event.
We couldn't resist searching records relating to "Olympic games" in our new family history search engine - SuperSearch - and discovered really interesting information, such as this Kansas State University yearbook entry, demonstrating one student's ambition to win a gold medal in 1988 and discussing his time trials for the 1984 Olympics.
You can also try it for free - searching "Olympic games" or another keyword - that could lead to information about your family history.
As the Games draw closer, we''re interested in learning your personal Olympic stories. Have you competed? Do you have any Olympians in your family tree? If you're not sure, try a quick SuperSearch and see what you discover.
Let us know in the comments section below, or email your stories to email@example.com.