Mother in Law
Summary: The research suggests that narcissistic family cultures hide the parent with a personality disorder. The manipulator may have been manipulating for decades while being undiagnosed. The example listed here can be the father or mother-in-law. The mother may be masking more than the father's example, making it harder to spot.
Narcissism is passed on through the generations through abuse or learning traits and behaviours, so it won’t be just one person with a lack of empathy. Perception may require a complete rewire or be spotted easily, but it seemed professional insight early on as exposure starts to happen when control can’t be made over the other family.
Dysfunction and bias are unhealthy; the past generations may have continued the same behaviour so everything is normalised.