A term used to describe the spectrum of brain development. Girls tend to lean toward a female brain and boys toward a male brain, but there are some bridge or bi-gender brains (e.g., nearly equal qualities of male and female brains). (Gurian, Michael, PhD, and Patricia Henley, with Terry Trueman. Boys and Girls Learn Differently! CA: Jossey-Bass, 2001, pp 15-17)

Some males and females have brains that are “hard-wired” toward the middle of the gender-brain spectrum. They have higher-than average amounts of the opposite gender’s brain characteristics. (Gurian, Michael, PhD, with Barbara Annis. Leadership and the Sexes. SF CA: Jossey-Bass, 2008, p 6)