Joining the family business is usually a matter of choice, but when you grow up a Gracie a career in combat is the only way to earn a living.
Since moulding the teachings of a visiting Japanese judoka into their own martial art of Brazilian jiu-jitsu (BJJ) in the early 1900s, the Gracie family have changed the face of unarmed combat by turning the confused chaos of ground fighting into a dynamic science of joint-locks, chokes and strangles.
Royce Gracie became a household name in 1993 when he won the first Ultimate Fighting Championship by forcing a boxer, a wrestler and a savate specialist into submission on the same night.
Royce was a pioneer in mixed martial arts (MMA). He defeated bigger, stronger opponents and won three of the first four UFC events.
Igor Gracie lights up when he talks about his family. He speaks excitedly about Royce's exploits in the UFC, and rubs the black-and-grey portrait tattoo of his father "Rolls" on the inside of his bicep when he talks about him.
In a recent interview in Singapore, the Rio de Janeiro native also talked of the pride and pressure of being a Gracie.
"Everybody wants to beat a Gracie," said Igor, who divides his time between MMA fighting and teaching at his cousin Renzo's BJJ academy in New York.
"Everyone knows about our family and they want to beat us so much. But it's that kind of pressure that makes us better, makes us train harder.
"When they first developed BJJ my family went all over Brazil, challenging other martial artists to fights and beating them. So we are used to dealing with that kind of pressure."
Igor's father died in a hang-gliding accident at 31 but had a major impact on the evolution of BJJ, studying other martial arts and training regimes to improve conditioning and technique.
"I grew up in the fight world, grew up seeing my cousins fight, was behind the scenes at fighting events, Pride in Japan and the UFC," said Igor Gracie, who is due to fight in an MMA event in the US in February.
"I cannot imagine myself doing anything else. I cannot imagine growing up without BJJ. I tried. I went to law school for two years but I knew I'd never be a lawyer, so I switched to business school for another year and a half.
"But at the back of my mind I knew I wanted to teach BJJ and I knew I wanted to fight."
The Gracies are determined to popularise BJJ around the world, though Asia has proven a tough nut to crack, perhaps due to the predominance of regional martial arts such as taekwondo, karate, and judo. However, he sees great growth potential in Asia and hopes BJJ will gain the kind of worldwide popularity that earns it place in the Olympics.
"That's our dream but it's going to be hard," he said. "Meeting the Olympic criteria isn't easy and, to be honest, the judo people won't be happy. But since BJJ came from judo, perhaps we can go backwards a little and make something we can all be happy with."
The Gracies have been victims of their own success as the spread of BJJ meant they lost their early dominance in MMA.
While fighters in the early days were dependant on boxing or wrestling or kick boxing, today's athletes have many more weapons in their arsenal, taking bits and pieces of different martial arts to strike and grapple.
Igor says the Gracies are evolving too, training hard in Muay Thai, boxing and wrestling to supplement their BJJ base. Current rules governing the intensity of action on the ground, and fans' preference for knockouts, also makes a good stand-up game crucial.
"We created BJJ but we have to make sure we keep evolving with the sport. We can't stop or we'll get left behind."