XYY theory

Cards (8)

  • The XYY Theory
    A genetic condition in which a male has an extra Y chromosome, giving a total of 47 chromosomes
  • this condition of the XYY theory occurs in about 1 in 1000 male births
  • XYY condition
    • The presence of an extra Y chromosome can cause criminal behavior
  • Jacob (1965): 'Some XYY men have an increase in aggression compared to XY men, and have been labelled as "super males"'
  • XYY syndrome
    • Serial killer John Wayne Gacy was suggested to have the XYY syndrome
  • Some criminologists have suggested that Gacy was "born to kill"
  • Sex chromosomes
    Females have XX, males have XY. The Y chromosome determines maleness.
  • XYY theory involves an extra Y chromosome, giving XYY