3. role of hormones and chromosomes Flashcards
what are the chromosomes
explain the chromosomal structure for females and males
Chromosomes are made from genes, which are short sections of DNA that determine the characteristics of a living thing. There are 46 chromosomes in the human body arranged into 23 pairs- the 23rd pair determines the biological sex. The chromosomal structure for females is XX, and for males XY.
what determines a baby’s sex?
All normal egg cells have an X chromosome, whereas sperm carry an X or a Y chromosome, determining the baby’s sex when it fertilises the egg cell.
The Y chromosome carries a gene called ‘sex determining region Y’ (SRY).
what does it do?
causes testes to develop in an XY embryo. These produce androgens (male sex hormones).
what are the role of hormones prenatally?
Chromosomes initially determine a person’s sex but most gender development comes from the influence of hormones. Prenatally in the womb, hormones act upon brain development and cause the development of the reproductive organs.
roles of hormones post natal?
At puberty during adolescence, a burst of hormonal activity triggers the development of secondary sexual characteristics e.g. pubic hair.
Males and females produce many of the same hormones but
in different concentrations.
Androgens are primarily important in the development of males - the most widely known androgen is testosterone:
what is testosterone? what does it do during foetal development?
Is a male hormone, though it is present in females in small quantities. It controls the development of male sex organs during foetal development - if a genetic male produces no testosterone during foetal development, then no male sex organs appear. If a genetic female produces high levels of testosterone during this time, male sex organs may appear.
High levels of testosterone are also linked to
(evolutionary theory) what ?
aggression according to the evolutionary theory: aggression towards rivals allows the male to compete for the opportunity to mate, and as women tend for children it means men are more likely to take to hunter role and success would be enhanced by aggression.
AO3: give a strength of the biological approach
RESEARCH SUPPORT FOR TESTOSTERONE - Wang
There is research evidence supporting the role of sex hormones in gender development in males. The link between increased testosterone and sexual behaviour was confirmed in a study by Wang, who gave 227 hypogonadal (caused by men not producing enough testosterone) men testosterone therapy for 180 days. Changes in body shape, sexual function and libido were recorded in this period, and she found that testosterone replacement improved libido, mood and sexual function, while significant increases in muscle strength were observed in the sample.
This study shows that testosterone exerts a powerful and direct influence on male sexual arousal and physical development even in adulthood.
what is oestrogen
what syndrome can it lead to?
Is a female hormone that determines female sexual characteristics and menstruation. It also causes some women to experience heightened emotions and irritability during their menstrual cycle (premenstrual syndrome PMS). In extreme cases, PMS has been used as a defence in cases of shoplifting and murder. Some researchers dispute the existence of PMS as a viable medical category.
what is oxytocin?
what does it do? primarily in which gender?
Produced by women in much larger amounts than men, particularly because of giving birth. The hormone stimulates lactation and reduces the stress hormone cortisol and facilitates bonding referred to as the love hormone.
It is released in massive quantities after birth, making mothers fall in love with their baby. The fact that men produce less of this hormone has fuelled the stereotype that men are less interested in intimacy and closeness within a relationship. However, evidence suggests both sexes produce equal amounts of oxytocin in amorous activities such as kissing.
AO3: give a limitation of the biological approach
SOCIAL FACTORS IGNORED - Hofstede
Hofstede et al claims that gender roles around the world are much more of a consequence of social norms than biology.
The researchers equate notions of masculinity and femininity with whether whole cultures are individualist or collectivist. Countries that place individual competition above the needs of the community are more masculine in outlook, such as the US and the UK. Consequently, traditional masculine traits will be more highly valued within these societies.
This challenges the biological explanations of gender behaviour and suggests social factors may ultimately be more important in shaping gender behaviour and attitudes.
AO3: give a limitation of the biological approach
REDUCTIONIST
Accounts that reduce gender to the level of chromosomes and hormones have been accused of ignoring or underplaying alternative explanations. The cognitive approach would draw attention to the influences of thought processes such as schema. Even though changes in the thought process may come through the development of the brain, they are not adequately explained by the biological model. In addition, the psychodynamic approach acknowledges maturation as a factor but also point to the importance of early childhood experiences such as interaction within the family.
This suggests that gender is more complex than biological influences alone.
