atypical sex chromosome patterns

• Klinefelters syndrome

  • affects 1/1000 males
  • additional X chromosome - XXY
• Klinefelters characteristics

  • Physical characteristics:
  • Reduced facial hair
  • Long limbs
  • underdeveloped genitals
  • Breast tissue
  • co-ordination problems and clumsiness
  • Psychological characteristics:
  • poorly developed language and reading
  • passive and shy
  • dont respond well to stress
  • problems with memory and problem solving
• TURNERS SYNDROME

  • 1/5000 women
  • No second chromosome in 23rd pair - X0
  • 45 rather than 46 chromosomes
• Turners characteristics

  Physical characteristics

  • No menstrual cycle/ sterile
  • Limited breast development
  • Webbed neck
  • hips arent much bigger than waist
  • Immature appearance
  • Psychological characteristics:
  • High level of reading skills
  • performance on spatial, visual memory and math tasks is low
  • Socially immature
• S - contributes to nature-nurture debate

  • by comparing people with these conditions with chromosome-typical individuals it becomes possible to see behavioural and psychological differences between the two
  • can be logically inferred that these differences have biological basis
  • suggests nature has powerful effect on psychology and behaviour
• W - environmental explanations

  • problems jumping to nature conclusion
  • behavioural differences may be due to environmental and social influences
  • e.g. social immaturity in females with turner's syndrome may be because they are treated immaturely - people may react to their pre-pubescent appearance in a way that encourages immaturity and this may have an indirect impact on their performance in school
• W - small sample

  • only a third of people with kleinfelters are aware they have the condition and even fewer are subject to psychological research
  • limits extent to which generalisations can be made that their biology is responsible for their behaviour because generalisations are made from a very small sample
• S - practical application

  • likely to lead to earlier and more accurate and earlier diagnosis for these syndromes
  • shown that those identified and treated from a very young age had significant benefits compared to those diagnosed in adulthood
  • suggests increased awareness of these conditions has positive implications for the lives of these people