One common tool narcissists use is mirroring.
Mirroring is when a person pretends to share similar interests to you, or to feel & respond to things as you do, when the truth is they don’t share your interests, feelings or responses. They also can mimic your non-verbal acts, such as smiling when you smile, crossing their legs when you cross yours. Some even try to mimic personality traits, like empathy. Since they have no empathy of their own, they watch how you display empathy, & then try to act like you in order to make you or others think they have empathy.
Pretending they are like you gives them a way to bond with you. It makes you feel comfortable with them, because you believe you two are so much alike. After all, most people prefer to be with other people who are similar to them.
Narcissists use mirroring in order to lure new victims into a relationship with them or to patch ones they have damaged. The bonding that mirroring can form is a powerful tool, & narcissists know this all too well. When you are close with someone, you want to believe the best of them, & you don’t want to confront them if they have hurt you. You are more likely to let things slide if you love a person, whereas if an acquaintance did such things to you, you wouldn’t have a problem speaking up to them.
Although sometimes people naturally act like each other, mirroring is different. In some cases, such as very close friends or couples who have been married for a long time, the closeness of their relationship means they automatically adapt some of each other’s traits & mannerisms over time. It just happens without even trying. Mirroring however, happens immediately, & being in a close relationship has nothing to do with it.