Atypical sex chromosome patterns

Klinefelter's syndrome, Turner's syndrome

What is the chromosomal structure of Klinefelter’s syndrome?

XXY, 1/600 males have this, additional X chromosome, biologically male

What iare the physical characteristics of Klinefelter’s syndrome?

• Reduced body hair

• Breast development at puberty

• Underdeveloped genitals

• More susceptible to health problems that are usually associated with females, e.g. breast cancer

What are the psychological characteristics of Klinefelter’s syndrome?

• Poorly developed language skills and reading ability

• Passive, shy and lacking interest in sexual activity

• Respond poorly to stressful situations

• Problems with executive functions, e.g. problem-solving

What is the chromosomal structure for Turner’s syndrome?

XO, 1/5000 females have this, caused by absence of one of two X chromosomes leading to 45 rather than 46 chromosomes

What are the physical characteristics for Turner’s syndrome?

• No menstrual cycle, as ovaries fail to develop

• Broad ‘shield’ chest, no development of breasts at puberty

• Low-set ears, ‘webbed’ neck

• Hips not much bigger than waist

What are the psychological characteristics of Turner’s syndrome?

• Higher-than-average reading ability

• Lower-than-average performance on spatial, visual memory and mathematical tasks

• Tendency to be socially immature

One strength of the research is its contribution to the nature-nurture debate.

• Comparing both chromosome-typical and atypical individuals highlights psychological and behavioural differences

• Inferred that differences have biological basis, direct result of abnormal chromosomal structure

• Suggest innate ‘nature’ influences have powerful effect on behaviour

Counterpoint to research of its contribution to nature-nurture debate.

• Behavioural differences may result from social influences

• Social immaturity in Turner’s may be bc individuals are treated that way due to immature appearance

• Shows that it could be wrong to assume that differences in atypical sex chromosome patterns due to nature

Another strength of reserch is its application to managing conditions.

• Continued research leads to earlier and more accurate diagnoses and positive outcomes

• Study of 87 individuals w/ Klinefelter’s syndrome showed that those identified when young benefitted in terms of managing condition

• Increased awareness of conditions have real-world application

One limitation is there may be a sampling issue.

• Those who have most severe symptoms are included in Klinefelter’s database → typical profile distorted

• Use of prospective studies show majority of those with Klinefelter’s who don’e have cognitive or psychological problems, many are highly successful

• Suggests typical picture of Klinefelter’s syndrome exaggerated