Morning (2008) nyingakin buku teks biologi sekolah manengah ring periode 1952 - 2002 sane pangawit nyane katemuan pola sane pateh sangkaning 35% ngebahas ras ring periode 1983 - 92 sane pangawit nyane 92% kalaksanayang.
Morning (2008) looked at high school biology textbooks during the 1952–2002 period and initially found a similar pattern with only 35% directly discussing race in the 1983–92 period from initially 92% doing so.