- Created by: z_mills1
- Created on: 08-06-15 09:39
Role of genes and hormones
- Sex of a baby determined at conception
- 23rd pair of chromosomes are sex chromosomes->X or Y-> female(**) male(XY)
- From conception until 6 weeks -> developing embryos display no physical changes
- After 6 weeks -> crucial window for sexual differentiation begins and the genes inherited determine which sex organs, testes or ovaries will develop.
- Foetal hormones, consistent with being male/female are produced at this stage.
- SRY gene on Y chromosome in male triggers synthesis of H-Y antigen (a protein which causes gonadal ridges to develop into testes).
- If such antigen is injected into a female foetus at six weeks then a genetic female with male testes will result.
- Alternatively if drugs preventing H-Y from functioning are injected into a genetic male, they will be born with ovaries.
Role of genes and hormones
- Before six weeks -> male and female foetus’ have two sets of reproductive ducts -> male Wolffian system and the female Mullerian system
- During the third month of male foetal development -> testes produce testosterone -> stimulates the Wolffian system to develop further, along with a Mullerian-inhibiting substance -> causes the Mullerian duct to shrivel allowing testes to descend into scrotum
- Male genes promote the production of testosterone at certain times of development which impact how the brain develops structurally
Androgen Insensitivity Syndrome is when a genetic male exposed to too little male hormone results in the newborn appearing to be female but is genetically male.
Role of genes and hormones
Imperato –McGinley et al -> BATISTA family
- Pseudo hermaphrodite children in the Dominican Republic -> raised as girls, genetically male
- At puberty -> testosterone levels increased -> male sex characteristics developed, which were not prenatally developed due to a lack of male sex hormones during pregnancy.
- The boys adapted to their new gender with relative ease.
- Evidence that nature’s influence is stronger than nurture for gender development.
- Natural experiment -> realistic setting -> high ecological validity.
- Issue (biological determinism) -> effects of nurture were eventually weakened by nature through hormones -> suggests our behaviour/mental experiences related to gender are not changeable -> hold of genetics over our development is too powerful.
- Unusual case study -> rich, detailed data can be obtained, however, cannot be repeated and therefore findings cannot be generalised across populations -> low population validity.
- No ethical issues associated with animal lab based studies or trying to extrapolate findings from animals to humans, which much of the other research does.
- Findings are from Dominican Republic -> culturally biased -> difficult for the results to be generalised.
Role of genes and hormones
Young et al-> evidence for the role of sex hormones in animals and humans.
- Showed that female monkeys exposed to male hormones (during prenatal development), tended to engage in rough and tumble play compared to female counterparts who were not exposed.
- Lab-based -> extraneous variables can be controlled and it can be easily replicated.
- Issue (non-human animals) -> lacks external validity, as it cannot be assumed that humans will behave in the same way, therefore it is difficult to generalise the findings of the study due to differences in biology.
- It is important that Psychologists understand the laws regarding animal welfare and legislation; the smallest number of animals should be used where possible; the researcher must minimise stress and suffering; researchers must carefully calculate the usefulness of the research.
- Critics of animal research argue that the physiologies of humans/non-human animals are not similar enough to justify generalising conclusions from animals to humans.
- Ethical issues -> resolved by weighing costs against benefits -> may require an ethics committee to decide this before the research goes ahead.
Role of genes and hormones
Money and Ehrhardt -> research that opposes the biological explanation
- David Reimer (identical twin) -> circumcised at 8 months -> penis was burnt off.
- John Money advised parents raise him a girl -> David’s testicles removed and a ***** created and renamed Brenda -> reluctantly took female hormones (age 12)
- At school, Brenda was teased for her masculine gait. Age 14 -> parents confessed to her.
- Brenda started taking male hormones and became David.
- David had a relationship with a woman but struggled with life -> committed suicide at 38.
- This goes against Money -> stated gender identity is socially determined and can be changed regardless of the sex we are born with.
- Support (biological approach) -> demonstrates the biological drive for a particular gender.
- David shared the same pre-natal environment as his brother and was exposed to the same prenatal hormones.
- David had a masculinised brain and no social factors (brought up a girl) could override this.
- Results from this case study are scientific and objective results, although it is ethically questionable.
Role of genes and hormones
- Reductionist approach -> doesn’t consider the complexities of gender development and the cultural and environmental influences.
- It is also assumed that biologically determined characteristics cannot be changed, which research into hormones has shown is not the case.
- Gender development is part biological but environment plays a key role (nature vs nurture).
Gender dysphoria -> a condition in which people are uncomfortable with the gender to which they have been assigned. There is a feeling of mismatch between anatomy and gender identity, and wanting to be the opposite sex. It affects both males and females but the males to females outnumber the females to males.
Biological explanations suggest environmental pollution may be causing problems.
The insecticide DDT contains oestrogen -> may mean that males are prenatally exposed to high levels of these female hormones leading to a mismatch between genetic sex and hormone influences.
- Found that boys born to mothers who were exposed to dioxins (which can promote oestrogen) displayed feminised play.
- -> suggests hormones can influence gender identity as boys exposed to abnormal levels of oestrogen were more feminine with their behaviour, suggesting that gender identity does have a biological cause -> supports the biological explanation of GD.
- validity of biological explanation increases due to supporting evidence -> indicates that we can assume that biological factors do in fact play a key part in the development of the disorder.
AO2 - Vreugdenhil (evaluation)
- Methodological issues -> biological explanation of GD is weakened.
- Study based upon observation -> findings were entirely subjective to researcher observing them.
- What may considered to be 'feminine' to some may not be to another, and so this lack of objectivity lowers the internal validity of the study as we cannot be sure that the findings were not a result of researcher bias or other confounding variables.
- Subjective study -> makes it more difficult to establish a cause and effect relationship between biological factors and GD, therefore weakening the valdiity of the supporting study and in turn the biological explanation.
- Due to the lowered validity we cannot correctly assume that biological factors are the main driving force behind GD.
Brain sex theory
- A region of the brain known as the bed nucleus of the stria terminalis (BSTc) is twice as large in men than in women and contains twice the number of neurons.
- The number of neurons in the BSTc of male-to-female transsexuals is similar to that of the females -> suggesting that the size of the BSTc correlates with preferred sex rather than biological sex.
Chung et al. (challenged BST)
-> noted that differences in BCTc volume between men and women do not become apparent until adulthood, while most transsexuals report feelings of gender dysphoria as beginning in early childhood.
This suggests that the differences in BSTc volume do not cause gender dysphoria, but may be an effect.
Rametti et al. (support BST) studied the brains of FtM transsexuals and found that these individuals had a more similar pattern to those who share their gender identity (males) than those who share their biological sex (females) -> suggests that abnormal development of the brain can lead to GD.
The human brain undergoes considerable development pre-natally and continues to develop after birth. By the time it is fully developed, the child has also been subjected to numerous environmental influences, including gender socialisation. It then becomes impossible to detangle the effects of nature and nurture on both the brain and gender development.
One psychological explanation is that gender dysphoria is caused by childhood trauma or a maladaptive upbringing.
- Coates et al. studied one boy who developed GD.
- They suggested that this may have been a defensive reaction to his mother’s depression following an abortion. The trauma may have led to a cross-gender fantasy as a means of resolving this anxiety.
- However this explanation can be considered as deterministic as it proposes that our behaviour is determined by factor outside individual and doesn’t take into consideration the individual’s free will.
- Cole et al studied 435 individuals experiencing GD and reported that the range of psychiatric conditions experienced were no greater than that found in the normal population. Therefore GID is generally unrelated to trauma or pathological families.
The psychoanalytical view is based on Freud.
- He suggests that GID may arise through incomplete resolution of Oedipal conflicts during phallic stage of personality development and/or identification of inappropriate role model.
- Stoller proposed that GID results from distorted parental attitudes. In clinical interviews they observed overly close mother-son relationships which would lead to greater female identification and gender confusion.
- The Psychoanalytical view lacks empirical support and so the concepts are not falsifiable. There is an overemphasis on sexual influences, whereas theorists other than Freud consider social influences more.
- The approach can be criticised for its historical bias – Freud’s over emphasis on sex may be due to the fact he was working in an era of sexual repression which may not apply now or to other cultures.
Research is socially sensitive and ethical issues arise as a result of this. These issues include privacy; confidentiality; equality; scientific freedom: balancing the pursuit for scientific research against the obligation to protect those individuals involved.
Ethical guidelines are essential but they focus on protecting the individual rather than deal with all the possible ways in which the research might inflict harm of a group of people or a section of society.
- Natural Selectionis the driving force behind evolutionary change.
- The process by which physical and psychological traits are passed down from one generation to the next due to their advantages in terms of survival and reproduction.
- Males focused on developing better hunting strategies.
- Females involved in child rearing.
- Sexual selection selects characteristics which help individuals gain access to mates.
- Mate selection states that males compete for females and have to win the females and ward off any other male competition.
- Enlarged body size and lowered aggression thresholds have been seen as traits which have a selected advantage in gaining a mate, especially in male-male competition.
Buss -> explored what males and females looked for in a marriage partner.
- The study involved over 10,000 people from 37 different cultures.
- Main findings: Women desired mates who were good financial prospects more than men
- -> translated into a desire for men with resources/qualities that were linked to resource acquisition eg ambition.
- Men placed more importance on physical attractiveness -> research has consistently shown that physical appearance provides a wealth of cues to a woman’s health and hence her reproductive and fertility value.
- Men wanted younger mates – indication that men valued increased fertility in potential mates.
- Both sexes wanted mates who were intelligent (parenting), kind (long term relationships) and dependable (willingness to help mate in times of trouble).
- Large study conducted over many cultures -> increasing reliability/validity
- It pays to be choosy over mate selection -> joining forces with an attractive mate means offspring are of a higher quality and an individual’s genes are more likely to get passed on.
- Critics of Buss argued that males selected younger females as they are easier to control.
- Buss’s study may suffer validity issues -> results of the survey give an indication of expressed preference rather than a reflection of real life.
- Self-report mechanisms in the survey may also lead to social desirability bias.
Trivers (1973) differences between the sexes can be traced back to parental investment.
- This can be defined as the amount of time, energy and effort put in to, and the reproduction, and survival of, the child.
- Basically the mother’s parental investment in their offspring is greater than the father’s and ranges from conception to gestation to giving birth and subsequent nourishment and future care.
- For this reason it is argued that females therefore give careful consideration to the health, fitness and resources of a potential father.
- Instead male anatomy is designed for ensuring fertilisation and as they cannot become pregnant or give birth males can therefore afford to take more risks with sexual involvement and be more promiscuous as they have less to lose and can choose whether or not to invest in their offspring.
Buss et al supports the Parental investment theory.
- Asked 202 undergraduate students to think of a serious romantic relationship and state which would upset them more; 1) their partner falling in love with someone else or 2) their partner enjoying passionate sex with someone else.
- Found that 60% of males would be more upset with their partners infidelity compared to 17% of women and that 83% of women would be more upset with their partner falling in love with someone else.
- Support the parental investment theory and mate selection theory -> suggest that males would be more upset if their partner slept with someone else therefore they cannot be entirely sure that they are the father of the offspring.
- In addition, the results suggest that females would be more upset if their partner left them for someone else because then they would have no one to invest into helping the survival of their offspring.
AO2 - Buss et al.
- Study is limited in generalising the findings to the entire population because the sample is of undergraduate students only, therefore the age range is very small.
- Results are limited culturally -> study was only conducted in one environment (a university of the western world) -> cannot state that these results support the evolutionary explanation to gender.
- For the results of this experiment to be valid the study should be conducted cross-culturally with different age groups because they currently lack population validity.
- Another flaw -> participants answering these questions may be basing their opinion on real life experiences and feelings or on imagined experience and feelings.
- As we know, it is difficult to know how we would react and feel unless there is a sense of truly experiencing those emotions, therefore the results may have a biased viewpoint.
The evolutionary approach focuses on the fact that we are biologically predetermined to behave in a particular way.
- Deterministic -> completely ignores social explanations of gender development and differences.
- This is a problem because it only focuses on one side of the nature/nurture argument, suggesting that our environment makes no differences to our behaviour, which can be viewed as a socially sensitive area since it assumes that we cannot make our own decisions because we are only interested in ensuring the survival of our species.
- Therefore, the evolutionary approach to gender is ultimately suggesting that we have no free will in life.
It is important to study culture because differences that are universal indicate biological differences between the sexes but differences that arise from cultural comparisons could reflect areas of gender behaviour that are flexible and therefore culturally determined.
- Mead -> ethnographic approach to studying cultural differences -> conducting participant observation/interviews in various tribes in New Guinea(Arapesh/Mundugumor/Tchambuli tribes)
- Males/females in the Arapesh tribe had similar roles -> unaggressive/sensitive
- Opposite was found in Mundagumor tribe -> uncooperative, aggressive and war like.
- Tchambuli tribe -> women took on an economic role, men a home making/childrearing one.
- Mead’s work supports the idea that culture influences gender because it shows the importance of cultural factors in gender development as each of these tribes were seen to have different gender roles, shaped by the expectations and structure of the culture.
- -> supports idea that culture is important because the males/females were therefore responding to the cultural conditions of their society.
- Ethnographic approach (difficulties) -> translation of language/cultural norms will often be necessary -> inevitably involves making assumptions about the cultural influences on gender, which may be subjective -> reporting of cross cultural work is therefore biased by the researchers own norms and expectations.
- Being an observer within a group may also be a problem because the behaviour/dynamics of those being studied may alter as a result, making it hard to generalise the results.
Whiting and Whiting - supports Mead’s observations about flexibility in gender role.
- Studied child rearing practices in 500 families, from 6 cultures eg North America, the Philippines, India, Mexico, Kenya & Japan.
- Researchers integrated themselves into the communities, conducting daily, systematic observations of the children’s lives.
- The research supported the view that gender role is flexible and influenced by socialisation and cultural expectations because the roles undertaken were mainly influenced by how much work the boys and girls were expected to do and what it consisted of from a young age.
- E.g. girls were more likely to spend time with their mothers, completing domestic and child rearing tasks.
- -> lends further support that gender is a result of/influenced by cultural expectations -> shows that the cultural differences seen in men/women is brought about because of the tasks they are given from the early stage of life.
AO2 - Mead/Whiting and Whiting
- Strengths -> real life setting -> influences on gender have been looked at in a way that would not be ethically possible to manipulate in a lab -> research has ecological validity and can be applied in a real life context across different populations.
- Criticism -> attempts to classify cultures tend to oversimplify the differences that exist within cultures themselves -> generalisations are then made when considering cultural differences/influences and ignores the fact that gender development depends on many factors that may vary in the culture themselves.
- A further problem -> cultural determinism -> believed that researchers have emphasised the input of culture at the expense of ignoring biological influences, which means a biased view is being presented which ignores the contributions of many different factors on gender development.
- Also, the evidence has largely been collected by Western researchers working in a mixture of Western and non-Western cultures, leaving scope for cultural bias.
- Any emphasis on the cultural influence upon gender role also ignores the biological or evolutionary explanations of gender, which instead state that the role of hormones or genes and the need to ensure survival of genes and parental investment are more important factors in determining gender behaviour -> criticises the idea that culture is the key influential factor and disputes the idea that gender behaviour is due to nurture (as emphasised by cultural theories) and instead suggests that nature is a key factor.
Parents -> first socialising influence/role models therefore their expectations and stereotypes of how a boy or girl should behave will have a lasting impact on our gender schemas.
- Parents influence their children’s gender behaviour through the use of operant conditioning.
- Therefore behaviours that produce positive consequences are more likely to be repeated.
Smith and Lloyd (support)
- Asked adults to play with babies who were randomly given a boy or girls name and offered toys that were typically stereotyped. They found that adults typically stimulated boys through physical activities.
- -> supports the influence of parents on gender development as the study shows that parents use existing schemas of gender to interact with children.
- Strength -> conducted in a lab -> easily replicated as variables can be controlled -> increases the reliability of the results and researchers can easily repeat the study to see if the results are consistent.
- Weakness -> this lowers the ecological validity, as it was not conducted in a real-life environment.
Lytton and Romney
- Meta-analysis of studies that had looked at parental treatment of boys and girls.
- Mainly carried out in Western countries and considered the parental treatment of boys and girls socialisation with a total of 27,836 pps.
- Supports the claim that boys and girls receive different reinforcement for activities considered to be sex-appropriate.
- Strength -> Large sample size -> increases the reliability and findings can be generalised with confidence.
- Weakness -> studies are carried out in Westernised countries making the findings specific to those Westernised countries, and is therefore culturally bias -> reduces the population validity of the study as findings cannot be generalised to the wider population and thus also decreases the internal validity of the theory as its supporting evidence has just been weakened.
- Deterministic -> as the theory ignores the role of free will in that the children's behaviours are solely dependent on their parents and their reinforcement.
Peers -> offer a model of gender-appropriate behaviours.
- Peer pressure is a means of reinforcing a culture’s traditional gender roles.
- -> eg taunting/teasing a child who does not fit the traditional gender roles that other children in the peer group have been exposed to, (excluding that child from group activities).
- Perry and Bussey showed film clips to children (8-9yrs) of boys/girls selecting an apple or pear (gender neutral items). Children were given a choice of fruit and chose the fruit they had seen their same sex choose -> reinforces the influence of the gender role model over behaviour.
Langlois and Downs - support of the importance of peers.
- Found that when boys played with girls’ toys they were ridiculed/teased by their male peers supporting the link between peers and gender behaviour as early toy preference is shaped by peers, leading to the same sex groupings, further reinforcing gender behaviour.
- -> shows that playing with friends reinforces gender behaviour -> child is made fun of if playing with a toy that is ‘for girls’, supporting idea that peers are a social influence on gender role.
- Criticism -> small samples -> can't generalise results to wider population (unrepresentative).
- As children get older, it becomes more acceptable to engage in opposite-sex gender behaviour and boys and girls become more accepting of each other. This makes gender behaviour less evident and consistent, meaning that the theory does not apply at all ages.
Time spent in schools may also influence gender role behaviours.
- Peers/teachers may act as role models demonstrating gender stereotyped behaviour which might shape gender behaviour.
- Serbin et al (1st part) -> 9 female preschool teachers were asked to introduce a new toy each day to a class of 3-4 year old children.
- Teachers then asked them to demonstrate the new toy to the rest of the class.
- The toys were categorised into ‘boys toys’, ‘girls toys’ and ‘neutral toys’.
- They found that the boys were called up more often to demonstrate the fishing sets and the girls more often to demonstrate the sewing sets.
- (2nd part of study) -> sets of toys eg trucks/dolls were introduced into the class.
- 1st condition -> teacher introduced the toys in a gender stereotypical way e.g. “we can pretend we’re mummies washing the baby”.
- 2nd condition -> non-stereotypical introductions were made containing references to both sexes. The results show support for the role of school as a social context influencing gender.
- support because -> introduction of toys in a gender stereotypical way meant children were more likely to play with the toys assigned to their gender whereas no significant differences in toy choice were found when toys were introduced in a non-stereotypical way, suggesting school may shape gender behaviour. However -> difficult to separate influence of school on gender from other influences eg peers/parents -> therefore not possible to specify one context as the most influential
Theories into the social influences of gender development have been criticised for failing to consider the importance of nature. Research has found that biological factors eg genes also contribute to the development of gender appropriate behaviours.
Reductionist -> social theories do not consider the impact of biological factors and only considers situational factors -> fail to provide a holistic account and thus decreasing their internal validity.