PY0547_Week 8_Sex & Sexuality
Page 1: Introduction
Course: Sex & Sexuality
Institution: Northumbria University, Newcastle
Week: 8
Module Code: PYO547 Psychobiology I
Instructor: Dr. Fiona Dodd
Page 2: Pros and Cons of Sex
Discussion of the reasons for engaging in sexual activity.
Pros: 10 factors
Cons: 3 factors
Page 3: Reasons for Sexual Activity
Continuation of the species: Reproduction as a primary reason for sex.
Health and life risks associated with reproduction.
Many species can utilize asexual reproduction, raising questions about the necessity of sexual reproduction.
Page 4: Tinder and Reproductive Strategies
Discussion on modern dating apps (e.g., Tinder).
The joking proposition of cloning oneself instead of using dating platforms.
Page 5: Genetic Variation
Benefits of sexual reproduction:
More gene combinations arise.
Enhanced resilience to diseases and parasites.
Page 6: Lecture Focus
Topics of focus for the day:
The role of hormones and brain regions in sexual development and differentiation.
Understanding how sexual orientation is determined.
Page 7: Guidelines and Disclaimer
Approach sensitive topics with care during discussions.
Encourage respect in discussion boards and activities.
Acknowledgement of outdated terms in literature, emphasizing respect for updated terminology (e.g., avoiding the term 'hermaphrodite').
Page 8: Definitions
Sex: Defined as an individual’s biological sex determined by chromosomes (X and Y).
Gender: Socio-cultural identity, distinct from biological sex, allowing for broader identification.
Page 9: Sexual Development Overview
Introduction to the developmental aspects of sexual differentiation.
Page 10: Hormonal Functions in Development
Differentiation between organizing and activating sex hormones and their roles in sexual behavior and maturation.
Page 11: Sexual Differentiation
Overview of stages and processes in sexual differentiation.
Page 12: Genetic Basis of Sex
Fertilization Process:
Egg (XX) + Sperm (XY) => Zygote.
Page 13: Role of the SRY Gene in Womb
At 6 weeks gestation, SRY gene determines the development:
Produces Testis-Determining Factor (TDF).
TDF triggers male development; absence leads to female development.
Page 14: Development of Genital Structures
Before 7 weeks: Genital structures appear similar.
Male: Wolffian ducts; Female: Mullerian ducts.
Page 15: The Complexity of Sex Development
Infographic indicating the complexity of developing male and female characteristics at birth.
Page 16: Androgen Insensitivity Syndrome (AIS)
Definition of AIS:
XY fetus with functioning SRY but ineffective androgen receptors (AR).
Develops testes, female internal organs degenerate, external female genitalia develop.
Individuals typically identify as women.
Page 17: Biological Sex Spectrum
Explanation of various chromosomal combinations resulting in differences in biological sex spectra (e.g., XO, XXX, XXYY).
Page 18: Understanding Questions
Check understanding questions regarding sex chromosome combinations and the SRY gene's chemical product.
Page 19: Reinforcement of Understanding Questions
Reiteration of questions from Page 18 for assessment.
Page 20: AIS Definition Review
Reiteration of criteria and understanding questions regarding AIS.
Page 21: Further Q&A on AIS
Similar to previous pages, reinforcing understanding.
Page 22: Brain Differentiation by Sex
Focus on how brains of different sexes show differentiation.
Page 23: Male vs. Female Brain Structures
Brain structure differences that may influence behavior and cognition.
Page 24: Review of Literature
Complexity of literature regarding brain gender: thousands of brains analyzed.
Findings suggest no strict dichotomy in brain structures.
Page 25: Gendered Brain Characteristics
Observations of male and female brain size differences at birth.
Medial temporal cortex in males, DLPF in females being larger.
Page 26: Evaluating Literature
Reasons for mixed literature results:
Variation in samples, ages, sociological factors, methodologies, and biases.
Page 27: The Brain as a Mosaic
Diversity in Brain Structure:
Variability among individuals, revealing brain structures cannot be strictly categorized into male or female.
Page 28: Transgender Brain Studies
Limited studies on transgender brains focusing on structural differences.
Findings indicate similarities to cisgender individuals of identical preferences rather than natal sex.
Page 29: Nature vs. Nurture in Sexual Orientation
Discussion on the continuum of sexual orientation.
Page 30: Influences on Sexual Orientation
Various factors influencing sexual orientation:
Genetics, early hormonal influences, environmental factors.
Page 31: Genetics of Male Sexuality
Concordance rates in studies of male homosexuality regarding sibling relationships.
Page 32: Genetics of Female Sexuality
Concordance rates in studies of female homosexuality.
Page 33: Nucleus Volume and Sexuality
Investigative findings by LeVay (1991) showing brain structural differences between homosexual men and heterosexual individuals.
Page 34: Epigenetics and Sexual Orientation
The impact of epigenetic modifications in twins with differing sexual orientations.
Page 35: Fraternal Birth Order Effect
Increasing odds of homosexuality with each older brother due to maternal factors.
Page 36: Maternal Immune Hypothesis
Understanding maternal immune responses to male fetuses and its implication on sexual orientation.
Page 37: Family Dynamics and Sexuality
Studies indicating that family context might influence the likelihood of children exploring same-sex relationships.
Page 38: Family Structure Effects
No strong impacts of family structure types on boys’ sexual partnerships, but some effects seen in girls regarding sexual debut age.
Page 39: Scholar's Perspective on Nature of Sexuality
Emphasis on avoiding biological determinism or oversimplifications in understanding sexuality.
Page 40: Summary of Learnings
Major points discussed:
Evolutionary perspective on sex.
Hormonal regulation in sexual development and differentiation.
The biological-environmental interaction in sexuality.
Page 41: Limitations and Critiques
Acknowledge biases towards male homosexuality in current studies and lack of coverage for other sexual orientations and identities.
Page 42: Blackboard Activities
Suggested activities for students: critique of LeVay (1991) study, watching a TED Talk on intersex issues.