Milton Diamond

• Ph.D.
• Managing Director at University of Hawaiʻi at Mānoa

In this paper we examine the social and legal conditions in which many transgender people (often called trans people) live, and the medical perspectives that frame the provision of health care for transgender people across much of the world. Modern research shows much higher numbers of transgender people than were apparent in earlier clinic-based s...

Scientific evidence supports biological explanations for the development of gender incongruence, rather than parenting, social environment, or mental disorder. A variety of studies indicate that gender dysphoria correlates with differences in function and anatomy of the brain, in the people experiencing this discomfort. These differences are associ...

The Journal of Pediatric Urology has recently published several articles from the Annecy (France) Working Party on DSD. We question several of the presented findings and recommendations. In two key articles summarizing their review, the authors concluded that identified studies are not representative and suffer from methodological weaknesses, such...

Gender variance confronts widely held assumptions that children born as males will act like ‘boys’ and children born as females will act like ‘girls’. This imposed binary has the effect of perpetuating negativity towards people who express themselves with gendered variations in attire, behaviour or preferences. Despite the existence of gender-varia...

The relative contributions of genetic and environmental factors to the development of gender identity have been debated. Twins were studied that are concordant or discordant for gender identity status in order to provide clarification of this issue. An extensive library search yielded reports of 27 male and 16 female sets concordant or discordant f...

Title: Review of “Born Together—Reared Apart” by Nancy L. Segal, California State University, Fullerton Author: Milton Diamond Ph.D. Published in and copyright by Twin Research and Human Genetics, Volume 15, Issue 06, December 2012, pp 793-795 The Nature-Nurture (N-N) dichotomy has been argued for many years. Is it upbringing and rearing, with a...

Adults with gender-variant childhoods have often lived traumatic lives because of the attitudes and limited understanding that people in their environment had of the concept of gender variance. This study explores the childhoods of transgender adults with the aim to understand their gender-related difficulties as children, in order to identify thei...

ABSTRACT: A false statement has been published in your journal in an article by P. A. Lee and C. P. Houk. (2010) Article ID 563640. "The Role of Support Groups, Advocacy Groups, and Other Interested Parties in Improving the Care of Patients with Congenital Adrenal Hyperplasia: Pleas and Warnings."

Children with gender variance and their parents struggle with negativity on a daily basis due to ignorance regarding their issues and needs. This study explored professionals’ views of these issues and needs via a qualitative Internet survey. Responses were examined using content and thematic analysis. The dominant identified needs for gender-varia...

Parents of children with gender-variant behavior, while doing their best to handle their child's preferences and needs, are forced to contend with societal bias and assumptions that allow their children to be marginalized. This exploratory investigation aims to provide a basis for supporting all children with gender variance and their parents by id...

Pornography continues to be a contentious matter with those on the one side arguing it detrimental to society while others argue it is pleasurable to many and a feature of free speech. The advent of the Internet with the ready availability of sexually explicit materials thereon particularly has seemed to raise questions of its influence. Following...

This study investigated the functional brain organization of 68 male-to-female (MtF) transwomen and 26 female-to-male (FtM) transmen by comparing their performance with 36 typical male and 28 typical female controls on two indicators of cerebral lateralization: dichotic listening and handedness. A sex-differentiating dichotic test and a handedness...

No one is certain why a majority of individuals are heterosexual and a minority are homosexual, or why some of us accept the sex in which we are born and others do not. Most clues, however, point to genetic and endocrine forces interacting with postnatal social experiences. These biological factors set a bias with which the individual meets society...

The term homosexual refers to private behavior, the term gay to public behavior and association with a subculture. Although the majority of individuals who engage in homosexually oriented activities are probably closeted and unrecognized, others are open about their sexual preferences and desires. They may or may not be identified by mannerisms and...

Sexual orientation refers to the erotic-love-affectional partners a person prefers. In lay usage, one often speaks of a person as a homosexual or heterosexual, and indeed, people often refer to themselves the same way. Such usage, however, often links together those whose regular sexual partners are of the same sex with those whose same-sex encount...

A vocal segment of the population has serious concerns about the effect of pornography in society and challenges its public use and acceptance. This manuscript reviews the major issues associated with the availability of sexually explicit material. It has been found everywhere it was scientifically investigated that as pornography has increased in...

The authors question the limits of parental authority to consent to infant sex assignment surgeries and suggest that unnecessary life-altering surgeries should be delayed until the child has capacity to consent.

Debate on the relative contributions of nature and nurture to an individual's gender patterns, sexual orientation and gender identity are reviewed as they appeared to this observer starting from the middle of the last century. Particular attention is given to the organization-activation theory in comparison to what might be called a theory of psych...

In the United States the federal government has spent over $170 million annually to subsidize states and community organizations that provide abstinence-only sex education or abstinence until marriage sex education programs. Such an education not only stresses that abstinence until marriage is to be practiced but that any sexual activity outside of...

About a decade ago, a spate of articles were published that reviewed and criticized the overall management of newborns with intersex conditions.1, ² These articles stimulated critical examination of the broad area of intersexuality and of its management.

A theory of gender development is presented that incorporates early biological factors that organize predispositions in temperament and attitudes. With activation of these factors a person interacts in society and comes to identify as male or female. The predispositions establish preferences and aversions the growing child compares with those of ot...

Examines the decision of an Australian family court on gender identity disorder (GID) in children and adolescents. Real-life difficulties of young GID sufferers; Decision of the U.S. concerning the legal rights of transgendered individuals; Recommendation of less judicial involvement in deciding whether and how to treat minors with GID.

This article attempts to put changing terms, emphases, and views on the interrelated, but separate, concepts of sex, gender, and identity into perspective. Often, these facets of a person's life are intermingled and confused. To understand individuals whose lives are touched by any aspect of sexuality that is of interest to the medical community, k...

Two of the most common intersex conditions, androgen insensitivity and Klinefelter's syndrome, are described with an emphasis on aspects that are of relevance to psychiatrists. Attention is focused on commonalities and differences between these syndromes and particular attention is given to how persons who have these conditions manifest sexual and...

This article attempts to enhance understanding and communication about different sexual issues. It starts by offering definitions to common terms such as sex, gender, gender identity and sexual identity. Alternate ways to discuss one’s sexual attractions are also presented. Terms are defined or redefined and examples given of their preferred use in...

The authors challenge the practice of gender assignment surgeries of infants born with ambiguous genitalia and other differences of sex development (intersex conditions). They assert that the child's right to an open future should be preserved.

The present standard of practice in the management of ambiguous and traumatized genitalia was evaluated. Published cases of intersexuality and protocols for the management of traumatized genitalia were reviewed with consideration of the input of intersexual individuals. Independent research on different types of intersexuality is also presented. Th...

Following the publication of our article about a classic case of sex reassignment, the media attention was rapid and widespread, as was the reaction of many clinicians. Some wanted to comment or ask questions, but many contacted us directly or indirectly, asking for specific guidelines on how to manage cases of traumatized or ambiguous genitalia.

Van Howe and Cold are exactly correct when they say "the most important lesson to be learned from this tragedy [was that] consent was never given by the patient." We agree totally. For our conclusions, however, we were limiting our advice for cases similar to the one presented. In cases of a penis loss, we advised that the child continue to be rais...

In our article,1 we limited our recommendation for treatment to those cases similar in nature, ie, individuals whose only medical situation was that of having a traumatic loss of the penis postnatally. Dr Benjamin asks for advice on management for a much broader spectrum of conditions. He asks for (1) advice for those cases most likely to confront...

Dr Schwarz questions one of the statements in our article about sex reassignment.1 He wonders if we would not raise those individuals with CAIS as females. Indeed he is correct. We would raise as girls those phenotypically female individuals with CAIS. This is in keeping with our original statement because these individuals, because of their lack o...

Following the publication of our article about a classic case of sex reassignment,1 the media attention was rapid and widespread,2-4 as was the reaction of many clinicians. Some wanted to comment or ask questions, but many contacted us directly or indirectly, asking for specific guidelines on how to manage cases of traumatized or ambiguous genitali...

This article is a long-term follow-up to a classic case reported in pediatric, psychiatric, and sexological literature. The penis of an XY individual was accidentally ablated and he was subsequently raised as a female. Initially this individual was described as developing into a normally functioning female. The individual, however, was later found...

Research has established the broad mammalian developmental plan that genes on the sex chromosomes influence gonad development which determines gonadal hormone production (or its absence) leading to modification of the genitalia and simultaneously biasing the nervous system to organize adult sexual behavior. This might be considered the "gonad to ho...

It has long been proposed that the development of sexual orientation and sexual identity is due to an interaction of both constitutional and social forces (Diamond, 1965). A great deal of evidence has been accruing that nature sets a predisposition for these sexual developments and within such limits the environment works. Cases are presented in wh...

Gender dysphoric individuals typically recount histories of prolonged conflict between their bodies and their minds to the effect that they believe they are born into the wrong body. Also, typically, they tell of an early onset of dislike and avoidance of activities appropriate to their genetic sex and affinity with and practice of behavior pattern...

Theoretical understanding of psychosexual development, particularly in regard to sexual identity, has undergone several historical changes. Most notable has been the transition away from a learning paradigm, which held that individuals are psychosexually neutral at birth and that they develop their sexual identity due to rearing. This has shifted t...

The general public as well as the scientific community have use for accurate data on the size(s) of the heterosexual, homosexual, and bisexual populations. Uses include political, legal, medical, and social. The data upon which the typically used figures are dependent have come under scrutiny. This review of studies from the U.S. and elsewhere indi...

Twin pairs in which at least one twin is homosexual were solicited through announcements in the gay press and personal referrals from 1980 to the present. An 18-page questionnaire on the "sexuality of twins" was filled out by one or both twins. Thirty-eight pairs of monozygotic twins (34 male pairs and 4 female pairs) were found to have a concordan...

This last several years has seen several studies which have caught popular attention. Bouchard and colleagues (e.g., Bouchard et al., 1990) demonstrated uncanny similarities in behavior of twins reared apart. LeVay (1991), demonstrated the existence of a particular portion of the hypothalamus in homosexual men to be smaller than it is in heterosexu...

Physicians have key roles both in treating disease and educating their patients about health and disease-related issues. To assess which factors correlate with Austrian physician's willingness to treat and educate patients about HIV-related risk behaviors and deal with AIDS issues, we conducted a survey of general practitioners, internists, and der...

This first statewide study, using random phone interviews, found a community standard for the acceptance of sexually explicit material. Research shows respondents are conservative in voting for the death penalty and against the legalization of those drugs presently illegal, even marijuana. In other regards, Hawaiians think abortion should be only f...

Eight cases of autoerotic asphyxia deaths on Oahu are reviewed. Distinguishing features typically separate these deaths from intentional suicides or homicides. The sexual nature of these incidents is a salient feature of the death. The etiology of the practice is unknown but worth investigation.

Anthropological studies of human sexual behavior traditionally are difficult to conduct and to interpret because so much of any sexual behavior is private and must be understood through reporting by others rather than through direct observation. Sexual behavior between adults and nonadults is especially difficult to study, but an understanding can...

The copulatory performance of 18 sexually experienced male rats was tested 30 min after IP injection of the phenylpiperazine, Fluprazine Hydrochloride (4 and 8 mg/kg), or saline solution. Three 20-min tests with an estrous female were conducted at weekly intervals. Each drug dose produced a significant depressive effect on copulatory behavior (late...

In the context of how television has treated issues relating to human sexuality in the past two decades, this article explores a series of thirty color programs on sexual issues, produced in the mid-1970s. The series represents one of the first attempts to present the broad spectrum of sexology in a frank, but educational, format for tele­vision. T...

The removal of a single dominant individual has been shown to trigger a sex change in some coral-reeffish. In the saddleback wrasse (Thalassoma duperrey), however, female-to-male sex change requires visual stimulation from smaller conspecifics. This change is not dependent on the sex or color of the stimulus fish and can be inhibited by larger cons...

Oral behaviors within the typical sexual behavior pattern of the male hamster were investigated. Also studied were the effects of partial glossectomy. A significant amount of time was spent in oral activities. Glossectomized males showed a decrease in the frequency and duration of anogenital nuzzling of receptive females and an increase in the dura...

The proportion of induced abortions in a year that are repeat procedures rises over time, but this rate is as low as can be expected given the shortcomings of currently available contraceptives. There is no evidence that women substitute abortion for contraception. Teenagers and poor women have greater difficulty avoiding unwanted pregnancies.

Hamsters, housed in groups composed of one, two, four, or six females, with two males per group, were observed for a period of 60 days. The effect of such groupings on reproductive success was assessed by determining interference with pregnancy, lactation, maternal behavior, and litter survival. While there was little interference with the onset or...

unmated hamsters made pregnant, assisted by a single injection of progesterone at the time of artificial insemination, corpora lutea regressed and ovarian weight was adversely affected. Despite this early regression of corpora lutea and ovarian insult, these females remained pregnant until term when an inhibition of parturition was noted. In contra...

A means of providing educational and entertaining sex education to large groups of people has been subsidized and tried by the University of Hawaii College of Continuing Education and PBS television station KHET-TV. This first use of public and commercial mass media television education has been tested for its efficacy. Results indicate a scholasti...

During puberty ovarian, hypothalamic, and behavioral processes become coordinated to foster reproductive success. The present study investigated the lordosis capability as a possible limiting factor in the initiation of puberty.Intact and castrate female golden hamsters at 18 to 28 days of age were found capable of demonstrating an adult-like lordo...

A matched group of women who conceived during a 2-month period in 1971 was used to trace some parameters involved in their decision to carry their pregnancies to term or to seek an abortion. Several specific indices to the decision were considered: whether coitus was anticipated; whether the pregnancy was planned; whether birth control methods were...

The effect on adult sexual behavior of high doses of progesterone and testosterone given to neonatal male rats were tested and compared with the effects of administered estrogen, cyproterone, and cyproterone acetate. Results indicated that high doses of all the test substances affect male sexual performance; the direction of change, however, is dep...

Abortion experience in Hawaii, which was the first state to legalize induce abortion (in March 1970), at the request of the patient, is reviewed after its first year in terms of the number of abortions performed, the demographic and social characteristics of women seeking abortion, implementation of the law, and medical and legal complications. 364...

The possibility of a relationship between visual acuity and phases of the menstrual cycle was investigated in women at different stages of their cycles. Visual sensitivity, as measured by the ability to detect a test light, was found to be great at midcycle (approximately the time of ovulation), to stay high until menses, and then to decline abrupt...