Answer:
The answer is: Complementarity
Step-by-step explanation:
Complementarity is a social-psychological concept which states that in a social relationship, the individuals seek certain qualities and traits in their partners, that fill the gaps present in themselves. Therefore according to this theory, in order to feel complete, an individual looks for those traits and qualities in their partner that are absent in themselves.
Therefore, the concept of Complementarity is closely related to truism.