No? Lets say we intro-/extroversion is either heritable (with prob .5) or random(with prob .5). If both of your parents are introverted you have a 50% chance o

No? Lets say we intro-/extroversion is either heritable (with prob .5) or random(with prob .5). If both of your parents are introverted you have a 50% chance of inheriting the introversion of your parents or a 50% chance at a coinflip, which gives us 75% for introversion and 25% for extraversion.