Transcript 1-y-gender-genes

Starter:
Nature vs nurture recap…
Using the cards… identify what
behaviours are considered due to
nature and which are due to nurture
Half term work was to watch
Money
On the A3 paper, in pairs write some key
words, questions, thoughts, points you have
taken from the study in relation to how we
develop our Gender
 MONEY concluded that “gender identity is sufficiently incompletely
differentiated at birth as to permit successful assignment of a genetic male as
a girl. Gender identity differentiated in keeping with the experiences of
rearing”
 Concluded that “with surgery and hormonal therapy it is possible to
habilitate a baby with a grossly defective penis more effectively as a girl than
as a boy”
 Concluded that it is possible to rear a child to avoid ambiguity and
uncertainty of gender”
Update
 At age 13 Brendas parents told her and her brother the truth; Brenda then
had surgery and had a penis reconstructed, became David
 Brian abandoned his brother and developed schizophrenia- killed himself
 Age 30; David met a psychologist called Diamond- who published a paper
claiming that Moneys conclusions where wrong (Diamond and Signmundson
(1977)
 In 2000 David Reimer published about his life; he had marital difficulties, was
unemployed and had a brother who committed suicide. He was depressed
and angry. Committed suicide
Strengths
 The case study is detailed and
longitudinal so there is validity
 No procedures or controls so it is
natural and therefore results were
valid
 The data is qualitative so can be
analysed in depth; more valid
 The case has data from more than
one source; observation,
information from both parents,
Brenda’s own contributions
therefore it is more reliable
 Guidelines give permission to
parents of anyone under 18 to
give consent for participants.
 “Brenda” was told the truth when
his mother noticed he was
unhappy- interests at heart.
Weaknesses
 Study lasted 9 years but later
participant revealed he was not
happy as a girl and chose to live as
a man, so technically there was no
validity
 It is difficult to generalise from a
unique case; not everyone who is
brought up as a girl will have same
experience(mother and brother
suffering from depression)
 David did not consent to
procedures and have the right to
withdraw
 Study cannot be repeated so
cannot be tested for reliability
With regard to gender development
Today we are looking at the role of
genes and hormones.
Key Question
Are we born knowing we are male or
female?
Or
Is gender the product of
Nature or Nurture
Is our sense of maleness and femaleness
the product of our upbringing?
Spec check
•The role of chromosomes and hormones
(testosterone, oestrogen and oxytocin) in sex
and gender
•Atypical sex chromosome patterns;
Kleinfelter’s syndrome and turner’s Syndrome
Why are some people born male – but believe
they are really female?
Why are some people born female –
but believe they are really male?
We need to be able to explain the role of genes
and hormones in gender development
Genes
A chromosome is a double
chain of DNA
A gene consists of a long
strand of DNA
A GENE contains a set of
instructions. It is a carrier of
information.
Every nucleus in every cell in the
body contains a set of 23
Chromosomes.
Genes sit on chromosomes
Definition
Genes are units of information that are
inherited from our parents.
They control, or influence characteristics
such as risk of mental health disorders,
personality and sexual development.
Genes are sections of strands of a chemical
called DNA found in our cells.
RECAP:
•Each individual human has a genotype
this is the genetic make up.
•Each person has a phenotype which is
what the individual becomes when their
genes interact with each other and the
environment.
•I may have a genotype which indicates I
will grow tall. However if I grow up
without adequate nutrition this gene may
never become my phenotype
Some genes always lead to certain characteristics; these
are known as dominant genes – to produce a
characteristic, a dominant gene need to be on only one
of the pair of chromosomes.
Bb =
Some genes need more than one copy to produce a
characteristic; these are known as recessive genes –
if a recessive gene is present on only one of the pair of
chromosomes, the characteristic will not appear.
Bb =
bb =
However...
Recessive genes can be passed on and may appear in a
future generation.
Such characteristics can be aspects of appearance,
personality or behaviour
Examples of the effects of genes on humans
•Some diseases and characteristics are sex
linked – they are controlled by the sex genes.
e.g. most colour blind people are men.
Environmental triggers on genes
Sometimes genes do not influence physical
characteristics unless the ‘right’
environmental conditions occur.
These genes are known as
epigenetic
Sex chromosomes influence
sex/gender development
The 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
Chromosomes link to hormones: During this
process, sex hormones direct the sexual
development
An embryo will always develop as a
female unless instructed otherwise
• The instructions to become ‘male’ are on the SRY gene
found on the Y chromosome
• The SRY gene on the Y chromosome contains
instructions for the embryo to produce androgens
(male sex hormones) – in particular testosterone
• This causes the embryo to develop along the ‘male path’
Sexual development
Sex = when referring to the biological aspects of males
and females
At about 6 weeks gestation the GONADS = sex organs begin to develop…. but
no
there is
difference between the developing sex organs of males and
females at this stage.
The SRY gene in the Y chromosome produces a protein
called ‘testis-determining factor’ which instructs the
gonads to develop into testes rather than ovaries.
Once this has happened hormones take over…
HORMONE: TESTOSTERONE
• Not only is it instructing the Y gene to produce male sex organs but it
also acts on the hypothalamus to ensure the brain develops as a male
brain rather than a female brain!
• Certain skills = spatial ability and characteristics such as aggression
and competiveness
Just an example!
Research: put these in your research banks
• Young (1966) – when female mice were given
testosterone (and male mice female hormone) irreversible
usual gender related behaviours: hormones DO have a key
role in determining gender behaviour
• Money & Erhardt (1972) – found testosterone to have an
influence in gender related behaviours
• Deady et al (2006) – found a negative correlation
between high testosterone levels and maternal
personality and reproduction ambition …. Females
maternal drive IS affected by testosterone
• Goel & Bale (2008) – sex differences in stress and anxiety
may be due to levels of testosterone levels … lower in
females … more prevalent in females
HORMONE: OESTROGEN
• Much like testosterone impact on the male development, oestrogen effects the
female development
• Alongside the physical changes it also effects behavioural and psychological
developments
• E.g. PMT (premenstrual tension) – linked to emotionality, irritability and irrational
behaviour … lapses in self control which can lead to snit-social behaviour and even
criminal offences
• Menopause is the start of oestrogen levels lessening
• Oestrogen also affects the female brain : promotes neural connections so that
women use both hemispheres equally and behaviours such as cooperation and
sensitivity
Research: use your text books: don’t forget to put
these in your research banks
Mask:
• Albrecht & Pepe (1997)
• Fitch & Denenberg (1998)
• Alonso & Rosenfield (2002)
• Finkelstein (2013)
PHG:
Rodin (1992) has an interesting concept!
Conflicting evidence of hormones not affecting gender
development
Evaluation of the research: what do you
need to consider when looking at the evidence?
Pink Haired Girl is AMAZING!!! And will help with the A*
grades… there is so much more on the Digital book..
Please look
If behaviour is found to be universal/similar across cultures, we can conclude that
differences in behaviour are biologically based – nature. However, if behaviour is
found to be different across cultures, we may conclude that these behaviours are
nurtured by the environment. Mead’s (1935) evidence has been used to support
the idea of the environment being the main force in gender role (nurture). In the
Arapesh, both males and females exhibited non-aggressive gentle behaviour
associated with femininity in Western cultures. Both males and females in the
Mundugumor tribe behaved in a masculine way – aggressive and assertive. The
Tchambuli completely reversed sex roles as we know them. Women were
assertive, made decisions about the economic organisation of the tribe and looked
after the food. Men took few decisions and spent a lot of time looking after artistic
pursuits. As the behaviour of males and females in the three tribes is different and
different from that in the West, this suggests that gender is socially constructed
and not biologically determined.
More people from both sexes are identifying themselves as androgynous rather
than masculine or feminine. These individuals have the same
chromosome/hormone patterns as their ancestors, so this indicates
society/culture as having an effect, i.e. these differences are due to the influence
of nurture rather than nature or there would be change to gender role over time.
Task: read the info / text books on the hormone Oxytocin
and make notes
Don’t forget to use research to support
TASK: Evaluation of the role of hormones and chromosomes on Gender
development:
Write a CASTLES in your notes
- Consider the following:
- Are there any conflicting pieces of evidence to suggest hormone
and chromosomes don’t necessarily affect gender development?
Are there any problems with these themselves?
- Can we apply and of this research to the real world? Are there
any examples you could use to support this evaluation point?
- Most of the research is conducted on animals. What are the
problems / limitations associated with animal research? (there is
a hand out to help you with this)
- How is this tested? Are the research studies invasive? Do they
establish cause and effect?