Gender Identity Disorder: A Literature Review from a Developmental Perspective

Isr J Psychiatry Relat Sci - Vol. 47 - No 2 (2010)
Gender Identity Disorder: A Literature Review from
a Developmental Perspective
Tomer Shechner, PhD
Department of Psychology, Tel Aviv University, Ramat Aviv, Israel, and
Feinberg Child Study Center, Schneider Children's Medical Center of Israel, Petach Tikva, Israel
ABSTRACT
The present paper reviews the theoretical and empirical
literature on children and adolescents with gender
variant behaviors. The organizational framework
underlying this review is one that presents gender
behavior in children and adolescents as a continuum
rather than as a dichotomy of normal versus abnormal
categories. Seven domains are reviewed in relation to
gender variant behavior in general, and to Gender Identity
Disorder (GID) in particular: theories of normative gender
development, phenomenology, prevalence, assessment,
developmental trajectories, comorbidity and treatment.
Introduction
Gender identity disorder (GID) is one of the most
controversial diagnoses of the DSM-IV (1) and almost
incomparable in the complexity of its social, ethical and
political considerations to any other diagnosis. Because
not many children meet complete diagnostic criteria for
GID, the clinical experience of mental health professionals working with GID children and adolescents is
limited. What is far more common, however, are parents
seeking counseling about their children’s gender variant
behaviors, and therefore it is important to distinguish
between these two conditions. The aim of the present
paper is to review the available research data and clinical literature on gender variant behaviors in general,
and on GID in particular, in children and adolescents.
Terminology
In this section, a brief review of key terms in the field of
gender development is presented.
Address for Correspondence:
shechner@post.tau.ac.il
132
• Sex – The genetic, hormonal and anatomical characteristics that determine if one is a biological male or
a biological female.
• Gender – The psychological and cultural characteristics associated with biological sex.
• Gender role – Attitudes, behaviors and personality
traits that a society, in a given cultural and historical context, associates with the male or female social
role. Masculinity and femininity, the main concepts
in gender role, pertain to the presence of qualities
and behaviors in an individual that are consistent
with those expected from males and females.
• Gender identity – Perception of one’s self as male or
female. In children, gender identity is related to the
ability to reliably answer the question: “Are you a boy
or a girl?” The individual’s comfort with the sex and
gender categories assigned at birth is a major element
of gender identity.
• Sexual orientation – The sex of the person or persons to whom the individual’s sexual fantasies, sexual arousal and sexual activities are predominantly
directed. Sexual orientation ranges along a continuum from exclusive heterosexuality to exclusive
homosexuality and includes various forms of bisexuality. A less common sexual orientation is asexuality,
or the absence of sexual attraction to either sex.
Theories of Gender Development
Gender is one of the most salient social categories, and
it plays a major role in the way people define themselves
and experience their social world. Extensive theoretical
and empirical work has been invested in understanding
the mechanisms underlying the trajectories of gender
development. In this section, a brief description of theories of normative gender development is presented as
Tomer Shechner, PhD, Department of Psychology, Tel Aviv University, POB 39040, Ramat Aviv 69978, Israel.
Tomer Shechner
the basis for the discussion of gender nonconformity
which follows. (For a comprehensive review of gender
development theories, see 2, 3.)
Theories of gender development may be divided into
four types: psychoanalytic theories, gender essentialism,
environmental theories and cognitive theories.
Psychoanalytic theories of sex differentiation are
rooted in Freud’s early work. Freud (4) claimed that
a child’s gender role is determined during the phallic
stage. Fear of castration motivates the child to identify
with the same-sex parent, thereby incorporating that
parent’s gender roles and attitudes. These concepts were
later expanded by Horney (5), Chodorow (6) and others. Psychoanalytic theories are not amenable to empirical study and have therefore not received much empirical support (3).
Gender essentialism attributes gender differentiation
largely to biological differences and focuses on genetics, hormones and neurological factors. One example
is the evolutionary perspective which explains human
sex differences by the survival value of certain traits and
characteristics adopted by men and women in primeval
times (for example, see 7). Another is based on developmental neurophysiological studies of the causal effects
of different biological factors on sex-typing attitudes
and behaviors (for example, see 8).
Environmental theories explain gender development
according to learning theory. Three elements are required
for learning: the stimulus, the response to the stimulus
and the resulting behavior. Reinforcement increases
the probability that the behavior will recur, whereas
punishment decreases the probability. Learning theory
considers the organism to be passive and emphasizes
experience and the role of the environment in shaping
behavior. Accordingly, children learn expectations about
social gender by the reactions to their behavior of various
social agents, such as parents and teachers (9).
Cognitive theories claim that gender development is
shaped by children’s cognitive abilities, interests, knowledge and other personal characteristics. Liben (10)
divided cognitive theories into two approaches: cognitive-environmental and developmental-constructivist.
The cognitive-environmental approach emphasizes the
interaction of the environment with the individual’s personal characteristics. For example, Bussey and Bandura
(11) proposed that besides direct learning, gender
development involves learning through such advanced
processes as modeling and imitation, and these require
that the individual acquire certain skills and abilities.
Factors that contribute to the evolution and preservation of gender-typed behaviors include cognitive ability,
emotional state, motivation, past experience and anticipated outcomes. Similarly, social-cognitive theories
claim that gender-typed behaviors result from the triadic interaction among environmental events, personal
factors and behavioral patterns.
The developmental-constructivist approach to gender
development considers individuals to be active participants who seek, organize and use information they are
exposed to in social contexts. It includes three major
schools of thought: cognitive-developmental stage theory, gender schema theory and intergroup theory. For the
purpose of this paper, only the first two are discussed.
The cognitive-developmental stage theory (12) derives
from Piaget’s studies of cognitive development which
showed that cognition is the result of self-driven processes and not merely previous environmental experience. The same cognitive abilities that make it possible
for children to understand constancies in the physical
world such as the conservation of liquid quantity (i.e.,
that the quantity of liquid remains unchanged even if
the liquid is poured into a container of a different shape)
also make it possible for them to understand the consistency of gender. Kohlberg (12) described three cognitive stages of gender development: 1. Gender identity,
achieved at age 2-3 years, is the individual’s ability to
label him/herself as a boy or girl, and serves as the core
motivation for future gender-related behaviors. That is,
a child recognizing the fact that he is a boy leads him to
seek and perform activities his society defines as boylike. 2. Gender stability, reached at age 4-5 years, is the
ability of the individual to understand the lasting nature
of gender. 3. The final cognitive stage of gender development, gender consistency, reached at age 6-7 years, refers
to the individual’s ability to understand that gender is a
fixed category that does not change even in the face of
external or physical changes. The acquisition of cognitive
abilities of gender stability and consistency motivates the
individual to actively perceive, process and apply information about gender derived from the environment.
Gender schema theory focuses on the way in which
the individual’s attitudes and knowledge about gender,
termed collectively the gender cognitive schema, are
used as a cognitive prism through which information
from the environment is perceived and then manifested
as behavior. As formulated by Martin and Halverson
(13), the theory claims that young children understand
to which gender group they belong and formulate cog133
Gender Identity Disorder: A Literature Review from Developmental Perspective
nitive categories that classify stimuli (objects or activities) as appropriate for males or females (13). Thereafter,
stimuli encountered in the world activate this schema
and are evaluated accordingly. Stimuli that are congruent with individuals’ gender schema increase their
interest and prompt them to actively seek to acquire
gender-appropriate skills. In an extension of this theory, Liben and Bigler (2) proposed the dual-pathway
gender schema theory which emphasizes individual differences explicitly. The theory suggests two pathways
of development. One is an attitudinal pathway similar
to the gender schema of Martin and Halverson (13) in
which the individual’s gender attitudes lead him or her
to engage in one activity or the other, with a directional
link from the attitude to the specific behavior(s).The
second is a personal pathway with an opposite directional link in which the individual’s activity affects his
or her gender attitudes. In the personal pathway, the
individual’s personal interests are more dominant than
the gender attitude, and they determine if he or she
engage in a specific activity. This, in turn, can affect the
gender schema. For example, a boy who finds himself
in a situation where he plays with dolls may come to
believe that playing with dolls is for boys as well as for
girls. The dual pathway model is particularly relevant to
individual differences in gender behaviors in general,
and gender variant behaviors in particular (14).
GID Phenomenology
GID was first recognized as a psychiatric entity in the
DSM-III (15), where it was included as two separate
diagnoses by age: GID of childhood, and transsexualism (adolescents and adults). In the fourth edition of
the DSM (16), the two diagnoses were collapsed into
one, GID, with different criteria for children and for
adolescents and adults.
The DSM-IV-TR (1) lists four criteria (A-D) for the
diagnosis of GID (p. 576), as follows:
A − Strong and persistent cross-gender identification.
The individual meets this criterion if he or she is characterized by at least four of the following five features:
1. Repeated stated desire to be, or insistence that he or
she is, of the other sex.
2. Preference for cross-dressing and wearing stereotypical clothes of the opposite sex.
3. Strong preference for cross-sex roles in fantasy and
make-believe play.
4. Intense desire to participate in stereotypical games of
134
the opposite sex.
5. Strong preference for playmates of the other sex.
In adolescents and adults, cross-sex identification
is manifested by a constant statement of the person’s
desire to be, live as, and be treated as the other sex.
B − Persistent discomfort with one’s assigned sex or
a sense of inappropriateness in the gender role of that
sex. The individual meets this criterion if he/she has any
of the following features: in boys, a feeling of disgust
for their penis or testes, a wish not to have male sexual
organs, aversion toward rough-and-tumble play, and
rejection of stereotypical male activities and games; in
girls, a wish not to have female sexual organs, an assertion that she has or will grow a penis, and a marked
aversion towards normative feminine clothing. Affected
adolescents and adults are preoccupied with getting rid
of primary and secondary sex characteristics and/or
express beliefs that they were born the wrong sex.
C − (exclusion criterion) – The presence of a physical
intersex condition excludes the diagnosis of GID.
D − Clinically significant distress or severe functioning impairment due to the disturbance.
Prevalence of GID
There are no reported epidemiological studies of the
prevalence of GID in children or adolescents (17).
Most of the published data are derived from samples of
adults attending gender clinics for hormonal or surgical treatments, who represent only a specific segment
of the population with cross-gender identification and
behaviors. In addition, there is considerable empirical
evidence indicating that GID in childhood does not necessarily persist into adulthood. Therefore, it is reasonable
to assume that the prevalence varies by age (17).
One potential approach to determining the prevalence
of GID in normative samples is to use screening instruments that include items on cross-gender or cross-sex
identification (17), such as the Child Behavior Checklist
(CBCL) (18). Of the 118 items in the English version
of the CBCL, two measure cross-gender identification:
“behaves like opposite sex” and “wishes to be opposite
sex.” Like the other items, they are scored on a 3-point
scale of 0 – not true, 1 - somewhat true, and 2 - very
true. One study of non-referred children aged 4-11 years
reported that among the boys, 3.8% assigned a score of 1
(somewhat true) to the item “behaves like the opposite
sex” and 1.0% assigned it a score of 2 (very true). The
corresponding rates for the non-referred girls were 8.3%
Tomer Shechner
and 2.3%. The item “wishes to be the opposite sex" was
assigned a score of 1 by 1.0% of the boys and 2.5% of
the girls, and a score of 2 by none of the boys and 1.0%
of the girls (19). The findings suggest that there is a sex
difference in mild, but not extreme, cross-gender behaviors and that the tendency of children to behave like the
opposite sex is greater than their tendency to actually
wish to be the opposite sex. Very similar results were
reported in a recent study of Dutch twins (20). In the
Hebrew version of the CBCL there are only 113 items
none of which measure cross-gender identification.
Numerous studies reported consistent findings indicating significantly higher referral rates for boys from age
3 to 12, than for girls. However, this difference decreases
dramatically with age to almost no sex differences in
referral rates for adolescents (21). The earlier difference
might be explained by the relative tolerance of society
for gender nonconformity in girls during childhood but
not in adolescence, when gender roles intensify.
Assessment of GID
As is true for other DSM diagnoses, a systematic clinical interview is the most comprehensive tool for the
assessment of GID. The evaluation should include both
the child and the parents and, in some instances, also
teachers or other relevant social agents involved in the
child’s life. The clinical interview is difficult, because it
may deal with unpleasant experiences that can become
intensified, accompanied by feelings of shame or embarrassment. Sometimes a prolonged intake process is
needed before the parents or child feels secure enough
to talk openly about sex and gender identification issues.
Personal clinical experience suggests that many parents
do not even inform their young children of the reason
for attending counseling.
In addition to the clinical interview, the clinician has
several instruments with which to assess sex-typing
behavior. The Occupational, Activity and Trait Personal
Interest and Attitude Measure Scales for Children
(COAT-PM/AM) and Preschoolers (POAT-PM/AM)
have been applied in normative samples in the United
States (21, 22) and Israel (23). The Activities and Traits
domains of the personal interest questionnaires are recommended for the assessment of sex-typing behaviors and
preferences. Although they are not clinical measures, they
offer the possibility of evaluating the child in a pleasant
and nonthreatening manner. Although further empirical
research examining the utility of these measures in a clini-
cal context is necessary, there is some evidence that sextyping measures assessing play preferences, in particular
toy choice, can be useful in assessing children referred for
concerns about their gender development (24).
Several reviews and empirical studies have emerged
examining the common measures available for assessment of gender identification and gender roles for both
research and clinical purposes (for a review, see 25).
Developmental Trajectories in GID
Retrospective studies provide strong empirical evidence
that adults with a homosexual sexual orientation, with
or without a specific diagnosis of GID, have a high level
of recall of cross-gender behaviors in childhood. A
meta-analysis of these studies revealed that homosexual
men and women had significantly greater recollections
of such behaviors than heterosexual men and women
(26). This finding was later confirmed by others (for a
review, see 27).
To avoid the limitations of retrospective designs,
several groups conducted prospective studies of developmental trajectories for the identification of children
with GID. Probably the most important to date is the
work of Green (28) who compared 66 feminine boys
and 56 normative boys aged 4-12 years with a follow-up
measure for the available 44 feminine boys and 30 normative boys at ages 14 to 24 years. Homosexual fantasies were reported by 75% of the study group compared
to none of the controls, and homosexual or bisexual
behaviors were reported by 80% and 4%, respectively.
Of the 44 boys who completed follow-up, only one had
gender dysphoric feelings to the extent of considering
sex reassignment surgery. Later prospective studies
documented higher rates of 20% (29) and 16.1% (30)
for gender dysphoric mood among boys diagnosed with
GID or subclinical GID in childhood.
There is only one prospective study to date of the
developmental trajectories of masculine girls (31). At
enrollment, 60% of the girls met the criteria for GID
and 40% had subthreshold GID. At follow-up, 12%
had GID or gender dysphoria, 32% were classified as
bisexual or lesbian in fantasy, and 24% were classified
as bisexual or lesbian in behavior.
This body of prospective research suggests that GID
often remits from childhood to adolescence and adulthood. Furthermore, cross-gender fantasies and behaviors in childhood appear to be largely predictive of a
homosexual sexual orientation in adulthood (32). Liben
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Gender Identity Disorder: A Literature Review from Developmental Perspective
and Bigler (14) suggest a comprehensive explanation to
the developmental trajectories of GID. Using the dual
pathway model, they propose that both environmentalexogenous factors as well as internal-endogenous factors
may account for the longitudinal drop in GID. Cognitive
development from childhood to adulthood may lead to
complex thinking abilities, resulting in modification of
gender attitudes and behaviors. For example, a boy who
thinks that there are only two kinds of people, masculine boys and feminine girls, might perhaps reconcile his
own feminine interests by desiring to be female. It is reasonable to predict declines in GID over time as children
realize that there can be both more and less feminine
and masculine males and females. Changing cognitive
attitudes about “right” and “wrong” gender behavior is
likely to alleviate gender dysphoria.
Comorbidity in GID
Most of the systematic data on psychopathologies associated with a childhood diagnosis of GID are derived
from parental reports in screening measures such as
the CBCL (21). Zucker and Bradley (29) showed that
clinically referred children with GID have, on average, significantly more behavioral problems than their
siblings or non-referred children. Similar results were
reported from cross-nation and cross-clinic studies,
wherein children with GID had mean CBCL total score
in the clinical range, with a predominance of internalizing symptomatology relative to externalizing problems
(33). In a recent study, boys with GID had a significantly
higher total CBCL score than normative boys and normative girls, and significantly higher scores for externalizing symptoms than normative boys but not normative
girls. In addition, there were no differences in scores for
internalizing symptoms between the study and control
groups (34). These findings are not totally in line with
the theoretical model of GID proposed by Zucker and
Bradley (29) and Coates and Person (35), which emphasized the major role of anxiety and assumed a higherthan-normal level of anxiety in individuals with GID.
Two more recent studies of GID comorbidity have
used different psychopathological measures. One study
used a structured psychiatric interview with parents of
children diagnosed with GID (36). The results showed
that 52% of the children had one or more additional
psychiatric diagnoses, with more internalizing (37%)
than externalizing (23%) symptoms in both boys and
girls. However, only 31% had anxiety disorder.
136
In another study, anxiety was measured via physiological correlates of cortisol level, heart rate and
skin conductance in stressful situations. Although the
authors concluded that their data provided some evidence that children with GID are more prone to anxiety, the results indicated that children with GID showed
higher levels only in skin conductance but not in other
measures such as cortisol or heart rate levels (37).
Treatment
The complex ethical and social aspects of GID or subthreshold GID become all the more apparent when
considering treatment. The most acute ethical issue
concerns the relationship between gender nonconformity in childhood and later homosexuality. Although
parents often express concern about the future sexual
orientation of their child, homosexuality is not considered a mental disorder, and there is no justification for
applying psychological interventions that aim to prevent
it. In addition, empirical evidence from efficacy studies
of sexual conversion therapies of any kind are, at best,
extremely limited (38).
The DSM-IV diagnostic criterion B for GID makes
no clear differentiation between dissatisfaction with
one’s biological sex and dissatisfaction with gender
roles. This distinction is important because a child who
feels disgusted or alienated from his or her body organs
would probably exhibit symptoms similar to those of
body dysmorphic disorder (BDD), which is characterized by a preoccupation with either an imaginary or
slight physical anomaly that causes significant distress
or impairment of functioning. Furthermore, if the dominant clinical symptom is a persistent discomfort with
one’s own sex, treatment should focus on ways to aid
the child to accept and come to terms with his or her
body, assuming that drastic surgical or hormonal interventions are not tenable at that point in development.
For those situations in which hormonal treatments are
indeed appropriate, however, Cohen-Kettenis developed
a protocol for treatment of GID in adolescents desiring
sex-reassignment (21). The protocol guidelines distinguish between three types of physical interventions:
wholly reversible, partly reversible and irreversible
ones. Wallien and Cohen-Kettenis suggest that in order
to decide upon the appropriate physical intervention
(32), it is clinically important to discriminate between
children with persistent GID and children who will
eventually cease experiencing GID.
Tomer Shechner
If the dominant symptom is cross-gender identification or discomfort with assigned gender roles, treatment
is far more multifarious and complex. Because discomfort
with one’s biological sex is not an obligatory condition for
criterion B, it is disconcerting that a diagnosis of GID is
sometimes based exclusively on cross-gender behaviors.
Therefore, it is highly recommended to conduct an extensive intake to comprehensively assess both the child’s and
the parents’ difficulties and to formulate the treatment
goals accordingly. The fundamental principle guiding
treatment is the child’s well-being, which does not necessarily imply changing his or her gender behaviors.
It should be borne in mind that a diagnosis of GID
can subject the child to the social stigma associated with
being labeled mentally ill (39). At the same time, some
scholars argue that psychiatric labeling confers meaning
to an otherwise inconceivable behavioral pattern, thereby
reducing stigma, conflict and atrocities (40). Clinicians
are advised to take these advantages and disadvantages of
psychiatric labeling into account when making a diagnosis of GID or any other DSM-related disorders.
Clinical Aspects of Treatment
There are 13 single-case reports of behavioral interventions for GID, all based on an environmental approach
to gender development with a focus mainly on sextyped play behaviors (21). Entirely apart from ethical
considerations, behavioral interventions have been
found to be clinically ineffective. Some of the treated
children reverted to cross-sex play in the absence of the
reinforcing adult. Moreover, there was little generalization to untreated cross-sex behaviors (21).
Various individual and group psychosocial interventions for children and adolescents have been reported.
These focused primarily on acceptance, support and
self-esteem enhancement in addition to psychoeducation for both the children and their parents (for
example, see 41). Treatment goals included reducing
preoccupation with thoughts of gender identity issues,
social ostracism, body dysphoria and possible psychiatric comorbidities and dealing with negative thoughts
and emotions related to a possible future homosexual
orientation. Targeting the objective to the individual
child and family according to the intake information is
highly recommended.
The question of how to identify “right” and “wrong”
gender behaviors is very much an educational issue.
Thus, even if the therapist does not advocate changing sex-typing behaviors as a treatment goal, it is his
or her duty to provide the parents with the clinical and
research literature, so they can decide for themselves
the best way to cope with the situation. The therapist
must also accept the parental choice, provided it is not
harmful to the welfare of the child.
The involvement of the parents in therapy is also
crucial to preventing or alleviating problems in the
parent-child relationship that derive from the child’s
cross-gender behaviors. In addition, the parents themselves often report feelings of shame, blame and helplessness. Seeing a therapist on a regular basis may help
them understand and handle such feelings, eventually
leading them to accept their child more fully.
Zucker (17) suggested that parents be trained in
setting limits to the child’s cross-gender behaviors by
encouraging gender-neutral or sex-typed activities.
Parents can be shown how to encourage their child to
find alternative activities they consider more genderappropriate, such as same-sex peer interaction. Parents
must be cautioned, however, to be aware of the difference between empathic encouragement and harsh imposition. Others suggested that when parents bring a child
exhibiting gender variant behaviors to treatment in the
fear that the child will develop a homosexual orientation,
the appropriate change-orientated intervention should
target the parents rather than the child (39).
For those who oppose conceptualizing cross-gender
behavior as pathological the treatment goal is not to
change the child’s non-conforming behavior. Rather,
the central objective of treatment should be to change
the environment, in particular the parents, to accept
and support the child’s success in coping with negative social response to cross-gender behaviors (42). In
addition to seeking to increase parental acceptance and
support of their child’s cross-gender behavior, some
researchers and organizations have called for programs
aimed at teaching other children to accept and support
cross-gender behaviors in their peers (43).
Acknowledgements
The author wishes to thank Lynn S. Liben, for her helpful comments, and Gloria
Ginzach of the Editorial Board, Rabin Medical Center.
References
1. American Psychiatric Association. Diagnostic and statistical manual of mental
disorders, 4th ed., text revision. Washington, D.C.: American Psychiatric
Association, 2000.
2. Liben LS, Bigler RS. The developmental course of gender differentiation:
Conceptualizing, measuring, and evaluating constructs and pathways. Monogr
Soc Res Child Develop 2002;67:1-147; discussion 148-183.
3. Ruble DN, Martin CL, Berenbaum SA. Gender development. In: Eisenberg N,
137
Gender Identity Disorder: A Literature Review from Developmental Perspective
Damon W, Lerner RM, editors. Handbook of child psychology, Vol. 3. Social,
emotional, and personality development (6th ed.) Hoboken, N.J.: Wiley, 2006:
pp. 858-932.
and cultures: An empirical example and methodological guidelines. Paper
presented at the Society for Research in Child Development Conference,Boston:
2007.
4. Freud S. Three essays on the theory of sexuality. 1905: standard Edition. London:
Hogarth, 1953.
24. Fridell SR, Owen-Anderson A, Johnson LL, Bradley SJ, Zucker KJ. The playmate
and play style preferences structured interview: A comparison of children with
gender identity disorder and controls. Arch Sex Behav 2006;35:729-737.
5. Horney K. The dread of women. Int J Psychoanalysis 1922;13,348-360.
6. Chodorow N. Mothering, object-relations, and the female oedipal configuration.
Feminist Studies 1978;4:137-158.
25. Zucker KJ. Measurement of psychosexual differentiation. Arch Sex Behav
2005;34:375-388.
7. Cosmides L, Tooby J. Origins of domain specificity: The evolution of functional
organization. In: Hirschfeld LA, Gelman SA, editors. Mapping the mind:
Domain specificity in cognition and culture. New York: Cambridge University,
1994: pp. 85-116.
26. Bailey JM, Zucker KJ. Childhood sex-typed behavior and sexual orientation: A
conceptual analysis and quantitative review. Dev Psychol 1995;31:43-55.
27. Zucker KJ. Gender identity disorder. In: Weiner IB, editor. Adult psychopatology
case studies. New York: Wiley, 2004: pp. 207-228.
8. Liben LS, Susman EJ, Finkelstein JW, Chinchilli VM, Kunselman S, Schwab J,
Dubas JS, Demers LM, Lookingbill G, D’Arcangelo MR, Krough HR, Kulin HE.
The effects of sex steroids on spatial performance: A review and an experimental
clinical investigation. Dev Psychol 2002;38:236-253.
28. Green R. The "sissy boy syndrome" and the development of homosexuality. New
Haven: Yale University Press, 1987.
9. Mischel W. Sex typing and socialization. In: Mussen PH, editor. Carmichael’s
handbook of child psychology, Vol. 2. New York: Wiley, 1970: pp. 3-72.
30. Cohen-Kettenis PT. Gender identity disorder in DSM? J Am Acad Child Adolesc
Psychiatry 2001;40:391.
10. Liben LS. Cognitive approaches to gender development. In: Blakemore JEO,
Berenbaum SA, Liben LS, editors. Gender development. New York: Taylor &
Francis, 2008: pp. 197-226.
11. Bussey K, Bandura A. Social cognitive theory of gender development and
differentiation. Psychol Rev 1999;106:676-713.
12. Kohlberg LA. A cognitive-developmental analysis of children’s sex role concepts
and attitudes. In: Maccoby EE, editor. The development of sex differences.
Stanford, Cal.: Stanford University, 1966: pp. 82-173.
13. Martin CL, Halverson CF. A schematic processing model of sex typing and
stereotyping in children. Child Dev 1981;52:1119-1134.
14. Liben LS, Bigler RS. Developmental gender differentiation: Pathways in
conforming and nonconforming outcomes. J Gay Lesbian Mental Health
2008;12:95-119.
15. American Psychiatric Association. Diagnostic and statistical manual of mental
disorders, 3rd ed. Washington, D.C.: American Psychiatric Association, 1980.
16. American Psychiatric Association. Diagnostic and statistical manual of mental
disorders, 4th ed. Washington, D.C.: American Psychiatric Association, 1994.
17. Zucker KJ. Gender identity disorder. In: Rutter M, Taylor EA, editors. Child and
adolescent psychiatry, 4th ed. Malden, Mass.: Blackwell, 2006: pp. 737-753.
18. Achenbach T, Edelbrock C. Manual for the child behavior checklist and revised
child behavior profile. University of Vermont, Department of Psychiatry, 1983.
19. Zucker KJ, Bradley SJ, Sanikhani M. Sex differences in referral rates of children
with gender identity disorder: Some hypotheses. J Abnorm Child Psychol
1997;25:217-227.
29. Zucker KJ, Bradley SJ. Gender identity disorder and psychosexual problems in
children and adolescents. New York: Guilford, 1995.
31. Drummond KD, Bradley SJ, Peterson-Badali M, Zucker KJ. A follow-up study of
girls with gender identity disorder. Dev Psychol 2008;44:34-45.
32. Wallien MSC, Cohen-Kettenis PT. Psychosexual outcome of gender-dysphoric
Children. J Am Acad Child Adolesc Psychiatry 2008;47:1413-1422.
33. Cohen-Kettenis PT, Owen A, Kaijser VG, Bradley SJ, Zucker KJ. Demographic
characteristics, social competence, and behavior problems in children with
gender identity disorder: A cross-national, cross-clinic comparative analysis. J
Abnorm Child Psychol 2003;31:41-53.
34. Owen-Anderson AF, Jenkins JM, Bradley SJ, Zucker KJ. Empathy in boys with
gender identity disorder: A comparison to externalizing clinical control boys and
community control boys and girls. Child Psychiatry Hum Dev 2003;39:67-83.
35. Coates S, Person ES. Extreme boyhood femininity: Isolated behavior or pervasive
disorder? J Am Acad Child Psychiatry 1985;24:702-709.
36. Wallien MS, Swaab H, Cohen-Kettenis PT. Psychiatric comorbidity among
children with gender identity disorder. J Am Acad Child Adolesc Psychiatry
2007;46:1307-1314.
37. Wallien MS, van Goozen SH, Cohen-Kettenis PT. Physiological correlates of
anxiety in children with gender identity disorder. Eur Child Adolesc Psychiatry
2007;16:309-315.
38. Cramer RJ, Golom FD, LoPresto CT, Kirkley SM. Weighing the evidence:
Empirical assessment and ethical implications of conversion therapy. Ethics
Behavior 2008;18:93-114.
39. Langer SJ, Martin JI. How dresses can make you mentally ill: Examining gender
identity disorder in children. Child Adolesc Soc Work J 2004;21:5-23.
20. van Beijsterveldt CEM, Hudziak JJ, Boomsma DI. Genetic and environmental
influences on cross-gender behavior and relation to behavior problems: A study
of Dutch twins at ages 7 and 10 years. Arch Sex Behav 2006;35:647-658.
40. Zucker KJ. Commentary on Langer and Martin’s (2004) "How dresses can make
you mentally ill: Examining gender identity disorder in children." Child Adolesc
Soc Work J 2006;23:533-555.
21. Zucker KJ, Cohen-Kettenis PT. Gender identity disorder in children and
adolescents. In: Rowland DL, Incrocci L, editors. Handbook of sexual and
gender identity disorders. Hoboken, N.J.: Wiley, 2008: pp. 376-422.
41. Rosenberg M. Children with gender identity issues and their parents in individual
and group treatment. J Am Acad Child Adolesc Psychiatry 2002;41:619-621.
22. Liben LS, Bigler RS, Shechner T, Arthur A. Preschoolers’ sex-typing of self and
others: Towards coordinated lifespan measure. Paper presented at the Second
Gender Development Conference, San Francisco: 2006.
23. Shechner T, Liben LS, Bigler RS. Extending sex-typing measures across languages
138
42. Menvielle EJ, Tuerk C. A support group for parents of gender-nonconforming
boys. J Am Acad Child Adolesc Psychiatry 2002;41:1010-1013.
43. Bigler RS, Liben LS. Developmental intergroup theory: Explaining and reducing
children’s social stereotyping and prejudice. Curr Direct Psychological Sci
2007;16:162-166.