1. Today we will…
Consider how biological psychologists might explain sex & gender
Examine chromosomal influences on sex/gender development
Examine hormonal influences on sex/gender development
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2. What do biological psychologists believe about the causes of experience and behaviour?
How might a biological psychologist explain sex/gender differences between people?
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3. Sex chromosomes
Genetic blueprint for a person is organised into 23 pairs of chromosomes
22 pairs are both X shaped. the 23rd depends on whether the person is female or male
XX – female XY - male
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4. Sex chromosomes source: US National Library of Medicine
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5. Chromosomes & hormones
Everything develops as a female unless instructed otherwise
The Y chromosome contains instructions for the body to produce androgens (male sex hormones)
These cause the embryo to develop along the ‘male path’
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6. Development of ovaries, uterus and vagina
Sexual development XX
Development of ovaries, uterus and vagina
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7. XY Sexual development Androgens
Development of testes instead of ovaries
Testosterone
Development of penis; Changes to brain
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8. Hormones What might be the result if…
An XY foetus was insensitive to androgens?
An XX foetus was exposed to unusually high levels of testosterone?
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9. Atypical chomosomes Turner’s syndrome Klinefelter’s syndrome
XO – only one X chromosome on 23rd pair
Klinefelter’s syndrome
XXY – additional X chromosome on 23rd pair
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10. Atypical chromosomes
Would people with these syndromes (Turner’s, Klinefelter’s) appear male or female?
How might they be different from those with more typical chromosomes?
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11. Turner’s syndrome
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12. Photographs on next slide
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13. Turner’s syndrome
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14. Turner’s syndrome Physical differences (neck, stature)
Underdeveloped ovaries, lack of menstruation at puberty
Poor spatial and mathematical abilities
Poor social adjustment
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15. Klinefelter’s syndrome
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16. Photographs on next slide
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17. Klinefelter’s syndrome
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18. Klinefelter’s syndrome
Physical differences (stature, limbs)
Underdeveloped genitalia
Gynaecomastia in some cases
Poor language abilities, learning difficulties
‘Shy and passive’ temperament
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