It’s In Your Blood
The phrase goes back to the 1600’s, predating the field of genetics by almost 300 years.
The idea that how we act is literally running through our veins is often seen in expressions of negative emotions like animosity (bad blood), anger (my blood is boiling.), fear (blood run cold), cruel (cold blooded) and vengeful (out for blood).
Beyond colorful idioms, there is more truth to the idea than we may realize.…