Gender - Biological Influences on Sex and Gender Flashcards
What is the role of chromosomes?
- chromosome 23 determines biological sex
- Y chromosome has SRY gene
How is a baby’s sex determined?
Chromosomes are made from DNA - genes are short sections of DNA. Humans have 23 pairs of chromosomes - 23rd pair determines biological sex.
Under a microscope, these chromosomes are either X or Y shape. Female sex chromosome is XX and male is XY.
A baby’s sex is determined by whether the sperm that fertilises the egg is an X or a Y chromosome.
What is the SRY gene?
The Y chromosome carries a gene called the sex-determining region Y (SRY). This causes the testes to develop and androgens to be produced in a male embryo. Without androgens, the embryo develops into a female.
What is the role of hormones?
- gender development governed by hormones
- testosterone (key role in male development and aggression)
- oestrogen (key role in female development and behaviour)
- oxytocin (implicated in lactation and bonding)
How is gender development governed by hormones?
Prenatally hormones act upon brain development and cause development of the reproductive organs.
At puberty a burst of hormonal activity triggers the development of secondary sexual characteristics such as pubic hair.
Males and females produce the same hormones but in different concentrations.
What is testosterone?
Testosterone controls the development of male sex organs from the fifth month of foetal development.
Testosterone linked to aggressive behaviour in both genders, in humans and animals. For example, Van de Poll et al. (1988) showed that female rats injected with testosterone became more physically and sexually aggressive.
What is oestrogen?
Oestrogen controls female sexual characteristics including menstruation.
During the menstrual cycle some women experience heightened emotionality and irritability - pre-menstrual tension or pre-menstrual syndrome (a diagnosable disorder).
In extreme cases, PMS has been used (controversially) as a defence for violent behaviour in women.
What is oxytocin?
Women typically produce oxytocin in larger amounts than men.
- stimulates lactation post birth
- reduces the stress hormone cortisol
- facilitates bonding
- may explain why women are more interested in intimacy in relationships than men, though amounts are the same in men and women when kissing and cuddling
What are the strengths of the role of chromosomes and hormones?
- there is research support
What are the weaknesses of the role of chromosomes and hormones?
- some evidence is contradictory
- controversial nature of PMS as a medical category
- overemphasis on nature
- biological accounts oversimplify a complex concept
What research support is there for the role of chromosomes and hormones?
Dabbs et al. (1995) found, in a prison population, that offenders with the highest levels of testosterone were more likely to have committed violent or sexually-motivated crimes.
Van Goozen et al. (1995) found that male-to-female transsexuals (having oestrogen treatment) showed decreases in aggression and visuo-spatial skills; female-to-male transsexuals showed the opposite.
These studies support the role of sex hormones in gender-related behaviours such as aggression.
What evidence is contradictory?
Tricker et al. (1996) gave males either 10-weekly injections of testosterone or a placebo and found no significant differences in aggression.
Slabbekoorn et al. (1999) also demonstrated that sex hormones had no consistent effect on gender-related behaviour.
This research does not support the view that sex hormones determine behaviour.
Why is the controversial nature of PMS as a medical category a weakness?
Rodin (1992) claims PMS is a social construction rather than a biological fact. Feminists claim this is an example of the medicalisation of the lives of women by explaining their emotion in purely biological terms.
Others have questioned the medical category pre-menstrual syndrome on the grounds that it stereotypes female experience and emotion.
This suggests that there may have been some over-exaggeration of the impact of hormones on behaviour.
How is there an overemphasis on nature?
Social learning theory points to social context in the learning of our gender identity and role, suggesting it is not considered when focusing on biology.
The biological explanation cannot easily explain cross-cultural differences. In Western society genders are becoming more androgynous but this is less so elsewhere.
This suggests that there is too much of an emphasis on nature in this approach to understanding sex and gender.
How do biological accounts oversimplify a complex concept?
Biological approaches that reduce gender to the level of chromosomes and hormones have been accused of ignoring alternative explanations for gender development.
Other approaches stress thought processes (cognitive approach) or childhood experiences (psychodynamic approach).
Jus focusing on a biological understanding ignores other possible influences which point to a more complex process in gender development.
