In 1986 Signithia Fordham co-authored, along with Ogbu, a study which concluded that some African American students in a Washington, D.C., high school did not live up to their academic potential because of the fear of being accused of "acting white." Ogbu further echoed these findings in his 2003 book "Black American Students in an Affluent Suburb: A Study of Academic Disengagement" (which summarized his nine-month research on the educational gap between white and African-American students in the Shaker Heights City School District located in the upscale Cleveland suburb of Shaker Heights, Ohio). His book presents a cultural-ecological theory which highlights two sets of factors that shape minority students’ academic performance: 1) "the system" (the way society and institutions have historically treated and do treat minorities) and 2) "community forces" (how minorities respond to and interpret their treatment, which is highly dependent upon their unique history and minority status in America). He concluded that these students' cultural attitudes hindered their own academic achievement and that these attitudes are too often neglected by parents, educators and/or policymakers.