Susan D. Witt at Akron University states that parents have a strong influence on childhood development. A person starts to develop self-identity at a young age, and parents either overtly or unintentionally steer a child into male or female roles. Electricians, mechanics and plumbers are traditional male roles, while teachers, nurses and waitresses are traditional female roles. This is evidenced by a sex disparity in traditional careers. According to the American Association of Colleges of Nursing, in 2009 men make up only 5.8 percent of the nursing work force, despite a huge shortage of nursing professionals as of 2010.
Jatong Ahmed Baba wrote in his doctoral dissertation that ethnic cultural beliefs influence a person's sports consumption behavior. A person works, lives and interacts with other people and the values of his community influence self-identity. Baba stated that self-identity is intertwined with a person's cultural ethnicity. Citing Kahle and others, Baba further stated that individuals take the shared values of the community, and make them their own.
Researchers at the University of Oregon proved in 2009 that brain development is an influence on self-identity. When a series of questions was asked to different age groups, f-MRI scans of brains revealed younger ages process information differently than older adults. The research concluded that teen-agers, whose brains are not yet fully developed, rely on the opinions of peers for their own internalized self-identity formation.