in your blood, in the blood

8. PHRASE : oft v-link PHR

If a quality or talent is in your blood, it is part of your nature, and other members of your family have it too.

• Diplomacy was in his blood: his ancestors had been feudal lords.
• He has adventure in his blood.

.... Cobuild

in your blood:

as a basic part of your qualities or characteristics

• She always seemed to be acting, but she had the theatre in her blood, and performing was as natural for her as breathing.
• Related vocabulary: born to do something

... Cambridge Dictionary of American Idioms

in the blood and in one's blood:

Fig. built into one's personality or character.

• John's a great runner. It's in his blood.
• The whole family is very athletic. It's in the blood.

.... McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

http://idioms.thefreedictionary.com/blood