People prefer to use the instinct that they have developed the most. If the preferred instinct is a perceptive one then their second one will have to be a judging one, so it can aid the first one, and visceversa. The same happens with extroversion and introversion, if the first instinct is an extroverted one, then to complement it, the second one will have to be an introverted one, and visceversa. See more below: