Answer: Ethnicity
Explanation:
Ethnicity is a term that describes shared cultural practices, values, and beliefs of by a group of people. This might include shared but not limited to language, religion, and traditions, among other commonalities. The term “ethnicity” can be said to be "the idea that of people with the same ethnic origins" according to the question.
These kinds of delusion is known as being:
paranoid
When a person is being paranoid, he or she can not stop thinking of negative happenings or thoughts that may happen to him or her. These type of persons are suffering from the mental condition commonly known as paranoia
Thus, the answer is:
paranoid
