a chromosomal disorder wherein a female has four X chromosomes instead of the typical couple. Impacted females usually have small physical abnormalities and cognitive retardation; IQ's of impacted people have spanned from 30 to 80 in analyses.
Cite this page: N., Sam M.S., "XXXX SYNDROME," in PsychologyDictionary.org, April 29, 2013, https://psychologydictionary.org/xxxx-syndrome/ (accessed June 28, 2022).