Ray Blanchard | University of Toronto (original) (raw)

Papers by Ray Blanchard

Research paper thumbnail of Puberty-Blocking Hormonal Therapy for Adolescents with Gender Identity Disorder: A Descriptive Clinical Study

Journal of Gay & Lesbian Mental Health, Dec 29, 2010

Research paper thumbnail of A method yielding comparable estimates of the fraternal birth order and female fecundity effects in male homosexuality

Proceedings of The Royal Society B: Biological Sciences, Mar 18, 2020

Research paper thumbnail of The Relation of Birth Order to Sexual Orientation in Men and Women

Journal of Biosocial Science, Oct 1, 1998

Research paper thumbnail of Birth weight and two possible types of maternal effects on male sexual orientation: A clinical study of children and adolescents referred to a Gender Identity Service

Developmental Psychobiology, Oct 25, 2014

Research paper thumbnail of Male homosexuality and maternal immune responsivity to the Y-linked protein NLGN4Y

Proceedings of the National Academy of Sciences of the United States of America, Dec 11, 2017

Research paper thumbnail of The Prevalence of Only-Child Status Among Children and Adolescents Referred to a Gender Identity Service Versus a Clinical Comparison Group

Journal of Sex & Marital Therapy, Jul 11, 2016

Several studies indicate that homosexual males have a high proportion of older brothers compared ... more Several studies indicate that homosexual males have a high proportion of older brothers compared to heterosexual males. Natal males with gender dysphoria who are likely to be homosexual also display this sibship pattern. Until recently, there was little evidence linking homosexuality and/or gender dysphoria in females to unique sibship characteristics. Two studies have indicated that natal female youth clinically referred for gender dysphoria are more likely to be only children (Schagen et al., 2012 ; VanderLaan et al., 2014 ). However, these studies did not include control groups of youth clinically referred for other reasons. Thus, it is unclear whether the increased likelihood of only-child status is specific to gender-referred natal females. This study compared only-child status among youth referred to a mental health service for gender dysphoria (778 males, 245 females) vs. other reasons (783 males, 281 females). Prehomosexual gender-referred males were less likely to be only children than clinical controls. Contrary to previous findings, gender-referred females were not more likely to be only children, indicating that increased likelihood of only child status is not specific to gender-referred females, but is characteristic of clinic-referred females more generally.

Research paper thumbnail of Debate and Argument: Reply to James's "The Sex Ratios of the Sibs of Children with Psychiatric Diagnoses

Journal of Child Psychology and Psychiatry, May 1, 1998

Research paper thumbnail of Birth Order and Sibling Sex Ratio of Children and Adolescents Referred to a Gender Identity Service

Research paper thumbnail of Birth Order among Homosexual Men

Psychological Reports, Feb 1, 2003

Nicolosi and Byrd in 2002 summarized empirical research on birth order and sexual orientation in ... more Nicolosi and Byrd in 2002 summarized empirical research on birth order and sexual orientation in men, which research has documented that homosexual men have a later birth order than heterosexual men. They did not, however, note a more refined analysis of an earlier null finding by Siegelman. This 1998 reanalysis by Blanchard, Zucker, Siegelman, Dickey, and Klassen also confirmed the later birth order of homosexual men.

Research paper thumbnail of Birth order in girls with gender identity disorder

European Child & Adolescent Psychiatry, Mar 23, 1998

Research paper thumbnail of Birth order and sibling sex ratio in homosexual male adolescents and probably prehomosexual feminine boys

Developmental Psychology, 1995

The purpose of this study was to extend the findings, previously limited to adults, that male hom... more The purpose of this study was to extend the findings, previously limited to adults, that male homosexuals have a greater than average proportion of male siblings and a later than average birth order. There were 2 matched groups of 156 probands. The homosexual–prehomosexual (HP) group included boys referred to a specialty clinic because of persistent cross-gender behavior plus homosexual adolescents

Research paper thumbnail of Evidence for an Altered Sex Ratio in Clinic-Referred Adolescents with Gender Dysphoria

The Journal of Sexual Medicine, Mar 1, 2015

Research paper thumbnail of Older Brothers, Sexual Orientation, and a Maternal Immune Reaction to NLGN4Y: Our Response to Rao and Andrade (2019)

Journal of Psychosexual Health, 2019

Research paper thumbnail of Older Brothers, Sexual Orientation, and a Maternal Immune Reaction to NLGN4Y: Our Response to Rao and Andrade (2019)

Journal of psychosexual health, Jul 1, 2019

Research paper thumbnail of Fraternal Birth Order and the Maternal Immune

increasing the odds of homosexuality by approximately 33%. It has been hypothesized that this fra... more increasing the odds of homosexuality by approximately 33%. It has been hypothesized that this fraternal birth order effect reflects the progressive immunization of some mothers to Y-linked minor histocompatibility antigens (H-Y antigens) by each succeeding male fetus and the concomitantly increasing effects of such maternal immunization on the future sexual orientation of each succeeding male fetus. According to this hypothesis, anti-H-Y antibodies produced by the mother pass through the placental barrier to the fetus and affect aspects of sexual differentiation in the fetal brain. This explanation is consistent with a variety of evidence, including the apparent irrelevance of older sisters to the sexual orientation of later born males, the probable involvement of H-Y antigen in the development of sextypical traits, and the detrimental effects of immunization of female mice to H-Y antigen on the reproductive performance of subsequent male offspring. The maternal immune hypothesis mi...

Research paper thumbnail of A Dissenting Opinion on DSM-5 Pedophilic Disorder

Archives of Sexual Behavior, 2013

Research paper thumbnail of The DSM Diagnostic Criteria for Pedophilia

Archives of Sexual Behavior, 2009

Research paper thumbnail of The Sexual Brain

The Journal of Nervous and Mental Disease, 1995

Research paper thumbnail of Corresponding author

The Fertility of Hebephiles and the Adaptationist Argument against Including Hebephilia in

Research paper thumbnail of Male homosexuality and maternal immune responsivity to the Y-linked protein NLGN4Y

Proceedings of the National Academy of Sciences of the United States of America, Jan 11, 2017

We conducted a direct test of an immunological explanation of the finding that gay men have a gre... more We conducted a direct test of an immunological explanation of the finding that gay men have a greater number of older brothers than do heterosexual men. This explanation posits that some mothers develop antibodies against a Y-linked protein important in male brain development, and that this effect becomes increasingly likely with each male gestation, altering brain structures underlying sexual orientation in their later-born sons. Immune assays targeting two Y-linked proteins important in brain development-protocadherin 11 Y-linked (PCDH11Y) and neuroligin 4 Y-linked (NLGN4Y; isoforms 1 and 2)-were developed. Plasma from mothers of sons, about half of whom had a gay son, along with additional controls (women with no sons, men) was analyzed for male protein-specific antibodies. Results indicated women had significantly higher anti-NLGN4Y levels than men. In addition, after statistically controlling for number of pregnancies, mothers of gay sons, particularly those with older brothers...

Research paper thumbnail of Puberty-Blocking Hormonal Therapy for Adolescents with Gender Identity Disorder: A Descriptive Clinical Study

Journal of Gay & Lesbian Mental Health, Dec 29, 2010

Research paper thumbnail of A method yielding comparable estimates of the fraternal birth order and female fecundity effects in male homosexuality

Proceedings of The Royal Society B: Biological Sciences, Mar 18, 2020

Research paper thumbnail of The Relation of Birth Order to Sexual Orientation in Men and Women

Journal of Biosocial Science, Oct 1, 1998

Research paper thumbnail of Birth weight and two possible types of maternal effects on male sexual orientation: A clinical study of children and adolescents referred to a Gender Identity Service

Developmental Psychobiology, Oct 25, 2014

Research paper thumbnail of Male homosexuality and maternal immune responsivity to the Y-linked protein NLGN4Y

Proceedings of the National Academy of Sciences of the United States of America, Dec 11, 2017

Research paper thumbnail of The Prevalence of Only-Child Status Among Children and Adolescents Referred to a Gender Identity Service Versus a Clinical Comparison Group

Journal of Sex & Marital Therapy, Jul 11, 2016

Several studies indicate that homosexual males have a high proportion of older brothers compared ... more Several studies indicate that homosexual males have a high proportion of older brothers compared to heterosexual males. Natal males with gender dysphoria who are likely to be homosexual also display this sibship pattern. Until recently, there was little evidence linking homosexuality and/or gender dysphoria in females to unique sibship characteristics. Two studies have indicated that natal female youth clinically referred for gender dysphoria are more likely to be only children (Schagen et al., 2012 ; VanderLaan et al., 2014 ). However, these studies did not include control groups of youth clinically referred for other reasons. Thus, it is unclear whether the increased likelihood of only-child status is specific to gender-referred natal females. This study compared only-child status among youth referred to a mental health service for gender dysphoria (778 males, 245 females) vs. other reasons (783 males, 281 females). Prehomosexual gender-referred males were less likely to be only children than clinical controls. Contrary to previous findings, gender-referred females were not more likely to be only children, indicating that increased likelihood of only child status is not specific to gender-referred females, but is characteristic of clinic-referred females more generally.

Research paper thumbnail of Debate and Argument: Reply to James's "The Sex Ratios of the Sibs of Children with Psychiatric Diagnoses

Journal of Child Psychology and Psychiatry, May 1, 1998

Research paper thumbnail of Birth Order and Sibling Sex Ratio of Children and Adolescents Referred to a Gender Identity Service

Research paper thumbnail of Birth Order among Homosexual Men

Psychological Reports, Feb 1, 2003

Nicolosi and Byrd in 2002 summarized empirical research on birth order and sexual orientation in ... more Nicolosi and Byrd in 2002 summarized empirical research on birth order and sexual orientation in men, which research has documented that homosexual men have a later birth order than heterosexual men. They did not, however, note a more refined analysis of an earlier null finding by Siegelman. This 1998 reanalysis by Blanchard, Zucker, Siegelman, Dickey, and Klassen also confirmed the later birth order of homosexual men.

Research paper thumbnail of Birth order in girls with gender identity disorder

European Child & Adolescent Psychiatry, Mar 23, 1998

Research paper thumbnail of Birth order and sibling sex ratio in homosexual male adolescents and probably prehomosexual feminine boys

Developmental Psychology, 1995

The purpose of this study was to extend the findings, previously limited to adults, that male hom... more The purpose of this study was to extend the findings, previously limited to adults, that male homosexuals have a greater than average proportion of male siblings and a later than average birth order. There were 2 matched groups of 156 probands. The homosexual–prehomosexual (HP) group included boys referred to a specialty clinic because of persistent cross-gender behavior plus homosexual adolescents

Research paper thumbnail of Evidence for an Altered Sex Ratio in Clinic-Referred Adolescents with Gender Dysphoria

The Journal of Sexual Medicine, Mar 1, 2015

Research paper thumbnail of Older Brothers, Sexual Orientation, and a Maternal Immune Reaction to NLGN4Y: Our Response to Rao and Andrade (2019)

Journal of Psychosexual Health, 2019

Research paper thumbnail of Older Brothers, Sexual Orientation, and a Maternal Immune Reaction to NLGN4Y: Our Response to Rao and Andrade (2019)

Journal of psychosexual health, Jul 1, 2019

Research paper thumbnail of Fraternal Birth Order and the Maternal Immune

increasing the odds of homosexuality by approximately 33%. It has been hypothesized that this fra... more increasing the odds of homosexuality by approximately 33%. It has been hypothesized that this fraternal birth order effect reflects the progressive immunization of some mothers to Y-linked minor histocompatibility antigens (H-Y antigens) by each succeeding male fetus and the concomitantly increasing effects of such maternal immunization on the future sexual orientation of each succeeding male fetus. According to this hypothesis, anti-H-Y antibodies produced by the mother pass through the placental barrier to the fetus and affect aspects of sexual differentiation in the fetal brain. This explanation is consistent with a variety of evidence, including the apparent irrelevance of older sisters to the sexual orientation of later born males, the probable involvement of H-Y antigen in the development of sextypical traits, and the detrimental effects of immunization of female mice to H-Y antigen on the reproductive performance of subsequent male offspring. The maternal immune hypothesis mi...

Research paper thumbnail of A Dissenting Opinion on DSM-5 Pedophilic Disorder

Archives of Sexual Behavior, 2013

Research paper thumbnail of The DSM Diagnostic Criteria for Pedophilia

Archives of Sexual Behavior, 2009

Research paper thumbnail of The Sexual Brain

The Journal of Nervous and Mental Disease, 1995

Research paper thumbnail of Corresponding author

The Fertility of Hebephiles and the Adaptationist Argument against Including Hebephilia in

Research paper thumbnail of Male homosexuality and maternal immune responsivity to the Y-linked protein NLGN4Y

Proceedings of the National Academy of Sciences of the United States of America, Jan 11, 2017

We conducted a direct test of an immunological explanation of the finding that gay men have a gre... more We conducted a direct test of an immunological explanation of the finding that gay men have a greater number of older brothers than do heterosexual men. This explanation posits that some mothers develop antibodies against a Y-linked protein important in male brain development, and that this effect becomes increasingly likely with each male gestation, altering brain structures underlying sexual orientation in their later-born sons. Immune assays targeting two Y-linked proteins important in brain development-protocadherin 11 Y-linked (PCDH11Y) and neuroligin 4 Y-linked (NLGN4Y; isoforms 1 and 2)-were developed. Plasma from mothers of sons, about half of whom had a gay son, along with additional controls (women with no sons, men) was analyzed for male protein-specific antibodies. Results indicated women had significantly higher anti-NLGN4Y levels than men. In addition, after statistically controlling for number of pregnancies, mothers of gay sons, particularly those with older brothers...