Role of chromosomes and hormones in sex and gender Flashcards
Explain the role of testosterone
- a male hormone produced prenatally and controls development of male sex organs.
- Also affects brain development prenatally and later in childhood. research has focused on behavioural effects of testosterone and its link to aggression. Human and animal studies have demonstrated the influence of increased testosterone on aggressive behaviour.
Explain the role of oestrogen
- a female hormone that determines female sexual characteristics and menstruation. The default gender is female so females do not need hormones to direct prenatal gender development.
- plays a major role from puberty onwards promoting secondary sexual characteristics such as breast development and the menstrual cycle. -can cause some women to experience heightened emotions and irritability during their menstrual cycle.
Explain the role of oxytocin
- women produce oxytocin in larger amounts than men and can be referred to as the love hormone.
- released in massive quantities during labour and after childbirth and makes the new mother feel ‘in love’ with the baby.
- it stimulates lactation making it possible for women to breast feed and reduces the stress hormone cortisol facilitating bonding.
- men producing less oxytocin has fuelled stereotype that men are less interested in intimacy and closeness in a relationship.
Pro of role of hormones: supporting evidence
Dabbs et al (1995) found that offenders with the highest levels of testosterone were more likely to have committed violent or sexually motivated crimes. This study therefore support the role of sex hormones in gender-related behaviour such as aggression.
role of hormones contradictory evidence
Tricker et al. (1996) gave males either 10 weekly injections of testosterone or a placebo and found no significant differences in aggression. This is consistent with further research, which has found that sex hormones had no consistent effect on gender development. This therefore questions the view that sex hormones determine behaviour.
role of chromosomes and hormones con: cross cultural research
Mead (1935) conducted research into three tribes in Papua New Guinea. In the Arapesh, both males and females displayed non-aggressive gentle, typically feminine behaviour. In the Mundugumor tribe both males and females behaved in an masculine way- aggressive and assertive and in the Tchambuli tribe sex role behaviour was completely reversed. This suggests that the environment has a larger influence on gender development as if the main cause was biological (e.g. Hormones) then the same differences would be seen across all tribes.
con of the role of hormones:stereotypes
the role of oestrogen has lead to negative stereotypes. Some people object to the medical category pre-menstrual syndrome on the grounds that it a social construction, which privileges women over men. Therefore, some feminists would argue that by creating these stereotypes women’s emotions are being dismissed by explaining them in biological terms.
Explain Klinefelters syndrome and give physical and psychological characteristics
biological males with the anatomical appearance of males and have an additional X chromosome(XXY. ) 1 in 1000 males have this condition. Diagnosis is often accidental via a medical examination for some unrelated condition.
physical-reduced body hair,breast development or softening of body contours,underdeveloped genitals
psychological-poorly developed reading/language skills,passive and shy and tend to not respond well in stressful situations
Explain Turner’s syndrome giving physical and psychological characteristics
caused by an absence of one of the two allocated X chromosomes(XO) so the individual has 45 chromosomes rather than the usual 46.Occurs in about 1 in 2000 females at birth.
physical-underdeveloped ovaries so lack of monthly periods,broad chest with undeveloped breasts and webbed neck with appearance of pre-pubescent girls
psychological-higher than average reading ability,lower performance on visual memory,spatial and maths skills, find it hard to fit in and are socially immature
Atypical sex chromosome patterns practical applications
Herlihy (2012) showed that individuals identified/treated from a very young age have significant benefits compared to those diagnosed in adulthood. Such research will therefore have a direct benefit to people who have these atypical chromosomal patterns as well as increasing our understanding of atypical development and the issues faced by those syndromes whilst allowing earlier diagnoses.
Atypical sex chromosome patterns nature vs nurture
Studies contribute towards our understanding of the nature-nurture debate in gender development as a whole. By comparing individuals with these conditions with individuals who have typical chromosomal patterns it allows researchers to identify differences in gender behaviour. For example, individuals with Turner’s syndrome tend to talk more than ‘typical’ girls. This therefore leads researchers to conclude that this is due to chromosomal differences providing evidence for the role of nature in gender development.
Atypical sex chromosome patterns con:uniqueness
Individuals with unusual conditions, particularly those with conditions that impact on their physical appearance, are unlikely to be treated the same way by their peers and the impact of environmental and/or social influences are more important than the research suggests.Social maturity in females with Turner’s syndrome may be due to the way others respond to their physical immaturity rather than a biological cause related to their chromosomes.This means that it is difficult to separate the contribution of nature and nurture on gender. Overall this therefore makes it difficult to generalise findings from case studies to all people who may have the gender conditions.
Atypical sex chromosomes con:typical and atypical gender behaviour
There is no such thing as typical and atypical gender behaviour. One of the symptoms of Turner’s syndrome is that females are socially immature compared to the vast majority of females. Research by Maccoby and Jacklin has actually found that there are significantly more gender differences within the sexes than between them. This therefore suggests that assumptions about typical gender behaviour are often based more around stereotypes than fact.
