The term "brother complex" was originally a slang term for
fetishism, but it was generalized by this term because fetishism and
complex were related concepts in
analytical psychology. When the other party is a sister, it is called a "
sister complex". In general, the brother complex is described as a sister who has "love feelings toward her brother" and "exclusive desire to own." For a woman with a brother complex, brothers, combined with sexual aspirations, can become an idealized image and have more influence on her life than her parents. For example, choosing a lover or spouse who has something in common or similar to her brothers. It may be accompanied by a negative image, and it may be seen as "making the brothers accept her selfishness to the maximum" or "treating the brothers freely and conveniently". On the other hand, the strong bond between male brothers is often seen positively as a symbol of masculinity. According to psychiatrist , women in the brother complex can become depressed or unstable when their brother has a lover or when they get married. Also, in such a case, she may feel jealous of her brother's partner, or may idealize her brother's partner as an entity that has acquired the love of her brother that she could not obtain. In order to appease her feelings, a woman in such a situation will, among things, decide to avoid her brother's home, depending on how attached she feels to him. According to a research conducted by
Mynavi Corporation on women with siblings by September 2019, more than 20% of women identified themselves as a brother complex. ==Cause==