Peter Sim vs. transgender people
Peter Sim aka “justdad7” and “justdad7180” is a retired Canadian lawyer and anti-trans extremist. Sim is a sex segregationist and is critical of gender affirming care for youth.
Sim co-authored a November 2025 article in Archives of Sexual Behavior with Chan Moruzi of the SEGM–McMaster partnership. SEGM paid the article’s open-access fees.
Background
Peter Sim grew up in Winnipeg, graduating from Kelvin High School in 1976. Sim then earned a bachelor’s degree from University of Winnipeg in 1979 and a lwa degree from University of Manitoba in 1982. Sim was called to the bar in Manitoba in 1983. Sim practiced at McJannet Rich from 1983 to 1993, then worked as a sole practitioner for three years before joining Perlov Stewart in 1997. Sim joined Thompson Dorfman Sweatman in 2010 through a merger with Perlov Stewart. Sim retired in 2022.
Sim served on the boards of Manitoba Naturalists Society, and Manitoba Associations for Rights and Liberties. Sim also served as a public representative on the Health Information Privacy Committee of Manitoba.
Anti-trans activism
Sim is active on Substack and X/Twitter as an anti-trans poster.
In the conservative National Post:
Psychotherapy “treats gender related distress, like any other form of distress, as something which emerges in a context which must be explored and understood,” Dr. Joanne Sinai, a clinical associate professor and psychiatrist at the University of British Columbia, and retired Winnipeg lawyer Peter Sim wrote in the Journal of the Canadian Academy of Child and Adolescent Psychiatry.
Under the gender-affirming approach, psychotherapy “plays little or no role,” they said. “In Canada, psychological assessment prior to hormonal therapy is typically minimal.”
References
Kirkey, Sharon (July 17, 2024). Kids identifying as transgender need ‘talk therapy,’ not drugs, therapists say. National Post https://nationalpost.com/news/canada/transgender-gender-dysphoria-treatment
Staff report (March 28, 2022). Peter Sim Announces Retirement. Thompson Dorfman Sweatman https://www.tdslaw.com/news/peter-sim-announces-retirement/
Selected anti-trans writings by Sim
Sim, Peter (January 22, 2026). Gender Medicine and the Pseudo-systematic Review: How the Utah Review Misleads the Public. Peter Sim’s Substack https://justdad7180.substack.com/p/gender-medicine-and-the-pseudo-systematic
Sim, Peter (September 6, 2025). More on the McMaster Mess. Peter Sim’s Substack https://justdad7180.substack.com/p/more-on-the-mcmaster-mess
Kulatunga Moruzi, C., Sim, P., Mitchell, I., Palmer, D. Joffe, Ari R. (2025). The Cass Review and Gender-Related Care for Young People in Canada: A Commentary on the Canadian Paediatric Society Position Statement on Transgender and Gender-Diverse Youth. Archives of Sexual Behavior 54, 3743–3761. https://doi.org/10.1007/s10508-025-03335-8
Sim, Peter (July 28, 2025). The Sullivan Review of data, statistics and research on sex and gender. The conflict between reality-based norms and gender identity theory in the United Kingdom. Peter Sim’s Substack https://justdad7180.substack.com/p/the-sullivan-review-of-data-statistics
Sim, Peter (April 28, 2025). Gender-based care for children should be based on science, not partisan whims. The Hill https://thehill.com/opinion/healthcare/5268027-partisan-divide-pediatric-gender/
Sinai J, Sim P (2024). Psychodynamic psychotherapy for gender dysphoria is not conversion therapy. J Can Acad Child Adolesc Psychiatry. 2024 Jul;33(2):145-153. https://pmc.ncbi.nlm.nih.gov/articles/PMC11201722/
Sim, Peter (November 7, 2023). Ignoring the Evidence: The Canadian Minister of Health gives a non-response to a petition on gender medicine. Peter Sim’s Substack https://justdad7180.substack.com/p/ignoring-the-evidence
Resources
X/Twitter (x.com)
LinkedIn (linkedin.com)
Substack (substack.com)
- justdad7180
- Peter Sim’s Substack
- justdad7180.substack.com
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