Issues in Interdisciplinarity 2019-20/Truth in Gender
Gender is observable through both empirical and social disciplines. Examining various truths in gender presented by different disciplines allows for a deep understanding of the difficulty of restricting the parameters of gender to a unique definition.
Sex and Gender
Individuals are initially biologically determined by their chromosomes. Males have a pair of XY sexual chromosomes whereas females possess XX chromosomes, resulting in hormonal differences that distinguish the two sexes. The Sex-determining Region Y gene, (on the Y chromosome), produces androgens (male sex hormones)responsible for the anatomical differences. This gene is not present in the X chromosome, resulting in the individual being female.
Secondary sex determination occurs when anatomical differences are created from different gonadal hormones produced. In males, testosterone promotes the development of structures such as the penis, facial hair and a deep voice while AMH induces degeneration of Mullerian ducts, resulting in the female reproductive tract being absent. Where testosterone and AMH are absent in females, degeneration of mesonephric ducts and differentiation of Mullerian ducts occurs, giving rise to the reproductive tract and other characteristics such as low muscle mass, breasts and high voice.
Gender encompasses the attitudes, roles and behaviours associated with being a given sex. It is a more fluid concept than sex, being perceived as a spectrum rather than dichotomy.
There appears to be no universal truth behind gender development. Theories typically compete on the basis of whether development occurs through environmental or biological factors.
Hormones play a key role in sex development, varying between the sexes and influencing gender development.
Testosterone, abundant in males, is released in the womb, causing the development of male sex organs and contributes to the ‘masculinisation’ of neural structures by affecting the hypothalamus. Higher levels are associated with reduced vocalisation and social engagement in toddlers and higher levels of aggression and competitiveness in adults, with female children given male hormone injections displayed more aggressive behaviour later in life.
Oestrogen Oestrogen is significant in female development by acting in the development of female sex organs and controlling the menstrual cycle. It is also linked to behavioural factors such as heightened fear responses.
Neural structures have been found to vary between the two sexes. The comparatively larger sexually dimorphic nucleus(SDN) found in male brainsis associated with higher aggression and copulating behaviour.  MRI scans have also shown that when engaging in language tasks, women utilised both left and right hemispheres whereas men used only the left, which suggests that females' brains have more complex phonological processing ability. This also displays the higher independence of brain hemispheres in males.
Chromosome-specific genes are believed to cause gender variations. Higher proportions of X-chromosome genes are associated with intellectual development, especially social intelligence, believed to cause the lower number of neurodevelopment disorders in females(approx.4:1). Evolutionary sciences are often utilised to explain the genetic differences.
Individuals with atypical chromosomes are studied and compared to isolate genetically-influenced behaviours that are genetically influenced. For example, those with Klinefelter syndrome(two or more chromosomes in males) are more likely to experience gender dysphoria displaying the connection between gender perceptions and chromosomes. Patients also showed more empathic responses towards verbal rather than visual stimulus. However, the results of such studies are mostly speculative as the responsible gene is often unidentified.
Such supporting observations in biological explanations allow for the establishment of a synthetic (empirical) truth. However there is no valid and complete way of measuring other environmental factors and motivations, resulting in observations being subject to a degree of interpretation and observer bias.
Advocates of social explanations reject biological explanations. For instance, PMS has been said to be more of a social construction rather than a biological fact, which is utilised by feminists as an example of the medicalisation of women’s lives through biological explanation of emotions, suggesting an exaggeration of the impact of oestrogen in previous studies.
Social Learning Theory
This theory suggests that gender is learnt through observation and imitation of others, focusing on environmental factors in gender development. Main processes involved are vicarious reinforcements and punishments - when behaviours are learnt through observations and judgements regarding their appropriateness based on the favourability of consequences.
Social learning theory suggests that boys and girls are differentially reinforced for different behaviours and this accounts for distinctly different gender roles, behaviours and attitudes. The child identifies with role models and imitates their behaviour. Four meditational stages in this process was identified- attention, reproduction, motivation and motor reproduction .
Smith and Lloyd (1980) observed adults with 4 to 6-month-olds. Boys were given a hammer-snapped rattle to encourage adventurousness whilst dolls were given to girls with reinforcement for passivity and 'being pretty'. This not only supports the role of differential reinforcement of gender-appropriate behaviours from early childhood, but also suggests that social explanations have temporal validity and explanatory power in terms of less rigid gender roles over time.
Anthropological cross-cultural studies illustrate differences in gender roles across cultures, thus highlighting the cultural influences on gender. Mead (1931) studied tribal groups in New Guinea and found differences in their behaviour. People in the Arapesh tribe took on feminine roles (gentle, responsive behaviours) while people in the Mundugumor tribe were aggressive and hostile (Western stereotype of masculinity). People in the Tchambuli tribe organised themselves along the reverse of the Western gender stereotypes where women organised village life and were dominant while men held decorative roles and were passive.
This approach deviates from both biological determinism and social constructivism, instead presenting gender to be influenced by biological factors but also malleable to social influences. Some biosocial approaches suggest that evolutionary differences caused by environmental characteristics between the sexes are no longer the same, resulting in alterations to sex chromosomes, such as the degeneration of the Y chromosome. 
Contemporary, meta-analytical methodologies allow for critical reassessments of previous biological and social studies. For example, in the examination of gendered variation of children's toy preferences, biological causes, such as girls exposed to higher levels of androgens displaying more interested in male-typed toys, are taken into account alongside social influences, such as stereotyped preferences displaying more consistently in group rather than dyadic circumstances. Further meta-regression detect that the gender equality status of subjects' country and year of study to have almost no effect on behaviour during early childhood where children still largely preferred gendered toys, but increases with age with deviated impacts, presenting the conclusion that the complex interaction between social and biological factors are what determines gendered preferences.
- Hiort O. The differential role of androgens in early human sex development. BMC Medicine [Internet]. 2013 [cited 13 November 2019];11(1). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3706224/
- Ganong, W. (2005). Review of Medical Physiology (22nd ed.). NY: McGraw-Hill
- Alexander, G. M. (2014). Postnatal testosterone concentrations and male social development. Frontiers in Endocrinology, 5, 15. https://doi.org/10.3389/fendo.2014.00015
- Hines, M. (1982). Prenatal gonadal hormones and sex differences in human behavior. Psychological Bulletin, 92(1), 56.
- M.A. Morgan, D.W. Pfaff, Effects of Estrogen on Activity and Fear-Related Behaviors in Mice, Hormones and Behavior, Volume 40, Issue 4, 2001, ISSN 0018-506X, https://doi.org/10.1006/hbeh.2001.1716.
- Hofman MA, Swaab DF. The sexually dimorphic nucleus of the preoptic area in the human brain: a comparative morphometric study. J Anat. 1989;164:55–72.
- Hofman, M A, and D F Swaab. “The sexually dimorphic nucleus of the preoptic area in the human brain: a comparative morphometric study.” Journal of anatomy vol. 164 (1989): 55-72.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1256598/
- Swaab D, Hofman M. Sexual differentiation of the human hypothalamus: ontogeny of the sexually dimorphic nucleus of the preoptic area. Developmental Brain Research [Internet]. 1988;44(2):314-318. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1256598/
- Ngun TC, Ghahramani N, Sánchez FJ, Bocklandt S, Vilain E. The genetics of sex differences in brain and behavior. Front Neuroendocrinol. 2011;32(2):227–246. doi:10.1016/j.yfrne.2010.10.001
- Shaywitz, B., Shaywltz, S., Pugh, K. et al. Sex differences in the functional organization of the brain for language. Nature 373, 607–609 (1995) doi:10.1038/373607a0
- Graves Jennifer A. Marshall (2004) The degenerate Y chromosome – can conversion save it?. Reproduction, Fertility and Development 16, 527-534. https://doi.org/10.1071/RD03096
- Printzlau, F., Wolstencroft, J. and Skuse, D.H. (2017), Cognitive, behavioural, and neural consequences of sex chromosome aneuploidy. Journal of Neuroscience Research, 95: 311-319. doi:10.1002/jnr.23951
- Abbott JK, Nordén AK, Hansson B. Sex chromosome evolution: historical insights and future perspectives. Proc Biol Sci. 2017;284(1854):20162806. doi:10.1098/rspb.2016.2806
- McLeod, S. A. (2014, Dec 14). Biological theories of gender. Simply Psychology. https://www.simplypsychology.org/gender-biology.html
- Parkinson, John. (2007). Gender identity in Klinefelter's syndrome and male hypogonadism: Four cases of dysphoria. Australian and New Zealand Journal of Psychiatry. 41. A70-A70.
- van Rijn S, Barendse M, van Goozen S, Swaab H (2014) Social Attention, Affective Arousal and Empathy in Men with Klinefelter Syndrome (47,XXY): Evidence from Eyetracking and Skin Conductance. PLOS ONE 9(1): e84721. https://doi.org/10.1371/journal.pone.0084721
- Rodin, J., & Timko, C. (1992). Sense of control, ageing, and health. In M. G. Ory, R. P. Abeles, & P. D. Lipman (Eds.), Aging, health, and behaviour (p. 174–206). Sage Publications, Inc.
- Mcleod S. Albert Bandura | Social Learning Theory | Simply Psychology [Internet]. Simplypsychology.org. 2016 [cited 15 November 2019]. Available from: https://www.simplypsychology.org/bandura.html
- Smith C, Lloyd B. Maternal Behavior and Perceived Sex of Infant: Revisited. Child Development. 1978;49(4):1263.
- Mead M. Sex and Temperament in Three Primitive Societies. 1st ed. New York: William Morrow and Company; 2003.
- De Melo‐Martín, Inmaculada. "When Is Biology Destiny? Biological Determinism and Social Responsibility." Philosophy of Science 70, no. 5 (2003): 1184-194. doi:10.1086/377399.
- Abbott, Jessica K et al. “Sex chromosome evolution: historical insights and future perspectives.” Proceedings. Biological sciences vol. 284,1854 (2017): 20162806. doi:10.1098/rspb.2016.2806
- Meyer-Bahlburg, H.F.L., Dolezal, C., Baker, S.W. et al. Arch Sex Behav (2004) 33: 97. https://doi.org/10.1023/B:ASEB.0000014324.25718.51
- Fabes, R.A., Hanish, L.D. and Martin, C.L. (2003), Children at Play: The Role of Peers in Understanding the Effects of Child Care. Child Development, 74: 1039-1043. doi:10.1111/1467-8624.00586
- Todd, BK, Fischer, RA, Di Costa, S, et al. Sex differences in children's toy preferences: A systematic review, meta‐regression, and meta‐analysis. Inf Child Dev. 2018; 27:e2064. https://doi.org/10.1002/icd.2064