Before I jump to the main thing, it is important to understand what constitutes as central and peripheral states of a being:

Central States: These are states of being that don’t change under the influence of others that easily. They require conscious efforts and time at an individual level. Major positive/negative events in one’s life can be a potential trigger for a change in these states. Ex: An incompetent person won’t turn competent overnight. The requirement for this change should be motivated by some major setback they faced in their life and even after that, it will demand a lot of effort. That doesn’t mean central states are not subject to change, they are, but that is a very gradual process and is hardly triggered by external influence.

Peripheral States: These are the states that change depending upon the social circumstances we are in. These changes are mainly motivated by us being able to fit into the social sphere of a particular place. We can think of them more in terms of experiences.

Test

For a sustained relationship, there should be coherence between the central states and a fair amount of divergence between the peripheral states. Now, the first point is pretty much self-explanatory. A competent and responsible person will find it extremely difficult to get along with an incompetent and irresponsible counterpart.

However, for peripheral states, divergence is ideal because it allows the two persons involved to become means for each other to add different experiences and opinions which will eventually broaden their socio-political understanding. And this process will help immensely in their social bonding, as without any active efforts and just by being with each other, they are constantly adding some or the other skills to their already existing social ledger.