The Biological Explanation for Gender Differences
A Biological Theory.
What does the Biological Approach say about Gender Differences?
As is obvious from the name, the biological approach focuses its efforts on explaining what biological differences between men and women result in their differing behaviours.
Of course, the biological approach and its theories is not necessarily the only approach to have a convincing argument for how gender differences arise.
All provide their own interesting ideas.
Read on to find out the biological theories.
Key Assumptions of the Biological Approach concerning Gender Differences
- Hormones play a huge role in gender differences and it is our DNA that dictates our behaviour as men and women.
- Men and women have different brain structures.
- Women have evolved to be the carers of children whilst men have evolved to be the providers for their families.
- Women have predetermined characteristics like being: more caring, protective and loyal than men.
- Men have predetermined characteristics like being: more aggressive, competitive and dominant than women.
- The fundamental cause of our gender differences is our genetic makeup, more specifically, the DNA found in our two 23rd chromosomes - the chromosomes that dictate which sex we are.
The Hormone System may explain Gender Differences
Other Brain Differences
Gender differences have also been found in the cerebral hemispheres of the brain. Scientists suggest that these differences cause the difference in the abilities of men and women:
Women excel in:
- Language skills
- Fine motor skills (using smaller muscles)
- Emotional control
Men excel in:
- Spatial skills
Chromosomes Cause our Genetic and so Gender Differences
Hormones - The Biological Cause of Gender Differences
- Hormones are chemicals in the body that regulate changes in our cells. This includes growth and is as a result very important in explaining our gender differences.
- You may have heard of the largely male hormone: testosterone and the largely female hormone: oestrogen - and know that they have effects in our bodies that lead men and women to act more like, well, men and women.
- It is well documented that there are differences between the brain structures of men and women (men have a larger hypothalamus - both the BSt and the SDN-POA). This can be seen by studying very young children (who have not yet had much social influence) and seeing if boys and girls act differently.
- The research made by Connellan et al. (2000) showed that newborn girls were more interested in faces (suggesting superior social skills) whilst newborn boys were more excited by mechanical items.
Chromosomes - The Fundamental Cause of Gender Differences
Humans typically have 23 pairs of chromosomes (totaling 46) and on the two 23rd chromosomes the DNA that decides whether a newly fertilised ovum (egg) becomes a male or female is found.
- If the sperm that fertilised the ovum is carrying a Y chromosome, then the zyoget (the name givne to an egg that has just been fertilised) will contain both an X and a Y chromosome and the baby will be a boy.
- If the sperm carried an X chromosome, then the zygote will have two X chromosomes (XX) and become a girl.
- The above statements are empirical facts and so we know that at its very core the cause of physical differences in men and women is due to biological differences in DNA.
At first, the embryo (the name given to a zygote that has started to develop) has the same sex organs whether or not it has XY or XX chromosomes. But 6 weeks after conception and the Y chromosome in males results in changes that lead to the gonads becoming testicles. If the Y chromosome isn't present (and the zygote has XX chromosomes) then the gonads become ovaries.
This idea that both males and females start off with the same sex organs is where the common 'fact' that 'all men were once women' comes from.
The formation of testicles and ovaries are very important because, as you may already know, they are the key producers for the sex hormones androgens (including testosterone) and oestrogens which, as mentioned in the above section, result in many gender differences.
Andrenogenital syndrome can be acquired by both embryos containing the normal XX chromosomes and embryos containing the normal XY chromosomes.
In females, the XY chromosomes for female development in the embryo result in the normal female genitalia as always. However, in andrenogential syndrome the genitals are exposed to abnormally high levels of male sex hormones (androgens). This results from a malfunction of the embryo's adrenal glands (which as well as the testicles produce androgens).
The result is that the females' genitalia look like that of a male's despite functioning normally (genitial ambiguity), as well as many secondary male characteristics (deeper voice, facial hair) also being present in these females too.
In a study by Money and Ehrhardt (1972) many of these females were found to identify themselves as tomboys - adopting the typical behavioural characteristics of men.
Females with andrenogenital syndrome, therefore, are used as evidence for the biological approach since their self identification as more manly than other women suggests that the hormones resulted in structural changes in their brains to make them more like that of their male counterparts (whose brains resulted from the very same hormones).
Studies Supporting The Biological Approach on Gender Differences
- Waber (1976)
Found that late maturing boys were better at verbal ability than boys who were early developers - suggesting that boys who had less male sex hormones were better (and so more likely to be encouraged to hone their) social skills - associated with female behaviour.
- Hampson and Kimura (1988)
Women were tested at different times of the month. At the times when their oestrogen and progesterone (female sex hormones) were highest, they performed best at fine motor skills but worst in their visual-spatial tasks compared to other times when the levels of these hormones were lower.
- Van Goozen et al. (1995)
Found that transsexuals who underwent 3 months of hormone therapy adopted increased intelligence in the areas that the sex hormones were associated with: female hormone takers gained skills in verbal fluency and became worse at visual-spatial skills and less aggressive. Those that took the male hormones showed the opposite.
- Galligani et al. (1996)
Found that athletes who had taken steroids (increasing levels of testosterone) were more aggressive (a male quality) than those that hadn't.
Tricker et al (1996)
- Tested the effect of testosterone and a placebo on aggression
- Used 43 males of age 19-40 were used.
- They were given either 600mg of testosterone a week or a placebo containing no testosterone.
- It was a double-blind experiment - neither participant nor researcher knew which
- The experiment lasted 10 weeks.
- No significant difference was found in aggression between the control group and the supplement takers.