Quotes Supporting the Biological and Medical Reality of Sex Differences.*

Dr. James Avery has made a public comment to the Fairfax School Board on why they ought not to teach that "sex is assigned at birth." You can read that full statement here:

Below are quotes collected from various sources - including the APA - which define sex biologically, not as being assigned at birth. The Fairfax County School Board will be voting on whether to approve the recommendation that FLE classes teach that "sex is assigned at birth" on June 14th.

Gender Concept: an understanding of the socially constructed distinction between male and female, based on biological sex but also including the roles and expectations for males and females in a culture.

American Psychological Association. (2015). APA dictionary of psychology (2nd ed.). Washington, DC

Gender refers to the attitudes, feelings, and behaviors that a given culture associates with a person’s biological sex.

American Psychological Association. (2012). Guidelines for Psychological Practice with Lesbian, Gay, and Bisexual Clients. American Psychologist, 67(1), 10–42. doi: 10.1037/a0024659

Sex refers to a person's biological status and is typically categorized as male, female or intersex. There are a number of indicators of biological sex, including sex chromosomes, gonads, internal reproductive organs and external genitalia.

American Psychological Association & National Association of School Psychologists. (2015). Resolution on gender and sexual orientation diversity in children and adolescents in schools.

Sex is assigned at birth, refers to one’s biological status as either male or female, and is associated primarily with physical attributes such as chromosomes, hormone prevalence, and external and internal anatomy. Gender refers to the socially constructed roles, behaviors, activities, and attributes that a given society considers appropriate for boys and men or girls and women. These influence the ways people act, interact, and feel about themselves. While aspects of biological sex are similar across different cultures, aspects of gender may differ.

American Psychological Association, "Answers to Your Questions About Transgender People, Gender Identity, and Gender Expression," http://www.apa.org/topics/LGBT/transgender.pdf. Accessed 4-2-2018.

sex       Biological indication of male and female(understood in the context of reproductive capacity), such as sex chromosomes, gonads, sex hormones, and nonambiguous internal and external genitalia.

American Psychiatric Association. “Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5).” 2013. 829.

The different biological and physiological characteristics of males and females, such as reproductive organs, chromosomes, hormones, etc.

The World Health Organization. “Gender Mainstreaming for Health Managers: a Practical Approach.” 2011. http://www.who.int/gender-equity-rights/knowledge/glossary/en/ 

An X-carrying sperm produces a female (XX) embryo, and a Y-carrying sperm produces a male (XY) embryo. Hence, the chromosomal sex of the embryo is determined at fertilization.

T.W. Sadler, Langman's Medical Embryology (Philadelphia: Lippincott Williams & Wilkins, 2004), 40.

The male sex is determined by presence of a Y sex chromosome (XY), and female sex is determined by absence of a Y chromosome (XX).

William J. Larsen, Human Embryology (New York: Churchill Livingstone, 2001).

The embryo's chromosomal sex is determined at fertilization by the kind of sperm (X or Y) that fertilizes the oocyte; hence, it is the father rather than the mother whose gamete determines the sex of the embryo. Fertilization by an X-bearing sperm produces a 46, XX zygote, which noramlly develops into a female, whereas fertilization by a Y-bearing sperm produces a 46, XY zygote, which normally develops into a male.

Keith L. Moore and T.V.N. Persaud, The Developing Human: Clinically Oriented Embryology (Philadelphia; Saunders/Elsevier, 2003) 35.

The underlying basis of maleness and femaleness is the distinction between the reproductive roles of the sexes; in mammals such as humans, the female gestates offspring and the male impregnate the female. More universally, the male of the species fertilizes the egg cells provided by the female of hte species. This conceptual basis for sex roles is binary and stable, and allows us to distinguish males from females on the grounds of their reproductive systems, even when these individuals exhibit behaviors that are not typical of males of females.

Lawrence S. Mayer, M.B., M.S., Ph.D., and Paul R. McHugh, M.D., "Sexuality and Gender Findings from the Biological, Psychological, and Social Sciences," Special REport, New Atlantis 50 (Fall 2016): 89.

Human sexuality is an objective biological binary trait: “XY” and “XX” are genetic markers of male and female, respectively – not genetic markers of a disorder… No one is born with a gender. Everyone is born with a biological sex. Gender (an awareness and sense of one’s self as male or female) is a sociological and psychological concept; not an objective biological one.”

American College of Pediatricians, “Gender Ideology Harms Children,” https://www.acpeds.org/the-college-speaks/position-statements/gender-ideology-harms-children. Accessed 4-9-2018.

In biology, an organism is male or female if it is structured to perform one of the respective roles in reproduction. This definition does not require any arbitrary measurable or quantifiable physical characteristics or behaviors; it requires understanding the reproductive system and the reproductive process. Different animals have different reproductive systems, but sexual reproduction occurs when the sex cells from the male and female of the species come together to form newly fertilized embryos. It is these reproductive roles that provide the conceptual basis for the differentiation of animals into the biological categories of male and female. There is no other widely accepted biological classification for the sexes.

Lawrence S. Mayer, M.B., M.S., Ph.D., and Paul R. McHugh, M.D., "Sexuality and Gender Findings from the Biological, Psychological, and Social Sciences," Special REport, New Atlantis 50 (Fall 2016): 90.

This statement [that the definition of biological sex is 'an extremely outdated view’] is stunning. I have searched dozens of references in biology, medicine and genetics-even Wiki!-and can find no alternative scientific definition. In fact the only references to a more fluid definition of biological sex are in the social policy literature.

Expert Rebuttal Declaration of Lawrence S. Mayer, M.D., M.S., Ph.D., U.S. District Court, Middle District of North Carolina, Case 1:16-cv-00425-TDS-JEP.

[M]any normal physiological functions-and, in many cases, pathological functions-are influenced either directly or indirectly by sex-based differences in biology…
Being male or female is an important fundamental variable that should be considered when designing and analyzing basic and clinical research…
The biological differences between the sexes have long been recognized at the biochemical and cellular levels…
These findings argue that there are multiple, ubiquitous differences in the basic cellular biochemistries of males and females that can affect an individual's health. Many of these difference do not necessarily arise as a result of differences in the hormonal regime to which males and females are exposed but are a direct result of the genetic differences between the two sexes.

Institute of Medicine, Committee on Understanding the Biology of Sex and Gender Differences, Exploring the Biological Contributions to Human Health: Does Sex Matter? ed. Theresa M. Wizeman and Mary-Lou Pardue (Washington, D.C.: National Academies Press, 2001), https://www.ncbi.nlm.nih.gov/books/NBK222287/.

[I]nate physiological differences between males and females may play a large role in sex differences in disease onset, susceptibility, prevalence, and treatment responses.

Rigby & Kulathinal, "Genetic architecture of sexual dimorphism in humans," Journal of Cellular Physiology, Volume 230, Issue 10, October 2015, 2034.

The sex chromosomes contain genes that determine the sex of an individual… The Y chromosome contains genes that cause male development. Therefore, any individual with a Y chromosome is male, and a male will have both an X and Y chromosome (XY). Females, without a Y chromosome, will have two X chromosomes (XX).

C-12 Foundation. “Biology 1.” 292-294. Open Source Biology Textbook. https://upload.wikimedia.org/wikipedia/commons/c/ce/High_School_Biology_1-13.pdf

Transgender people are a diverse group of individuals whose biological sex does not match their gender identity.

Quinn VP, Nash R, Hunkeler E, et al. Cohort Profile: Study of Transition, Outcomes and Gender (STRONG) to Assess Health Status of Transgender People. BMJ Open 2017;7:e018121. doi:10.1136/bmjopen-2017-018121

Sex differences in device therapy for heart failure: utilization, outcomes, and adverse events.

Herz ND et al. J Womens Health (Larchmt). (2015) https://www.ncbi.nlm.nih.gov/pubmed/25793483

The role of gender and sex hormones in determining the onset and outcome of multiple sclerosis.

Bove R et al. Mult Scler. (2014) https://www.ncbi.nlm.nih.gov/pubmed/24561324

Below are several Medical Sources that recognize the differences between the male and female sex which are important for diagnosis and treatment.

Sex-Based Differences in Knee Kinetics With Anterior Cruciate Ligament Strain on Cadaveric Impact Simulations.
Schilaty ND, Bates NA, Nagelli C, Krych AJ, Hewett TE. https://www.ncbi.nlm.nih.gov/pubmed/29568787

All three major methods for calculating the Glomerular filtration rate in kidney functioning considerthe biological differences between males and females.

Drug dosages for Ambien include a consideration of the biological sex of the patients.

Drug dosages for Revlimid include a consideration of the biological sex of the patients.

Drug studies compare results of administering Zolpidem between biological sexes.

*These definitions and quotes are used to demonstrate that the term “biological sex” is widely recognized in the scientific and medical communities. The use of these quotes does not reflect any agreement with the content of the studies, medical practices, or sources they originate from.