Cogenital Adrenal Hyperplasia: Gender, Behavior and Biology

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Cogenital Adrenal Hyperplasia Gender, Behavior
and Biology
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Issues

• In a non-experimental science, no single study is
  definitive
• Biological approaches are considered by many to
  be controversial
• Will biology be used to justify the status quo?

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Controversy At Harvard
Harvard president Larry Summers hypothesized that
the lack of women in science and math-related
fields could be due to innate sex differences
between men and women.
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Issues

• In a non-experimental science, no single study is
  definitive
• Biological approaches are considered by many to
  be controversial
• Will biology be used to justify the status quo?
• Can scientific progress be made when one class of
  explanations is judged a priori to be politically
  unacceptable?

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Gendered Behavior

• Gender Identity Sense of self as male or
  female, satisfaction with being male or female
• Sexual Orientation Based on sex of target of
  sexual arousal desire
• Gender-role Behavior (multidimensional) aspects
  of behavior that differ on average between males
  and females
• Toy preference play style
• Some aspects of personality
• Academic achievement and some abilities
• Risk for some mental illness

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Biological Sex

• Genetic constitution XX vs. XY
• Internal genitalia Ovaries vs. Testicles
• External genitalia Vagina vs. Penis

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the sex of rearing outweighs the biological sex
in the development of gender identity and social
identity.

• G. Herdt (1997). Same sex different cultures.
  Westview Press Boulder. Colorado (p. 47)

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Why might sexes differ biologically?
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Sexual Dimorphism in Beetles
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Sexual Selection

• Females and males faced different evolutionary
  problems
• Minimal parental investment

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Parental Investment Sexual Selection

• Sex that invests greatest resources in offspring
  rearing will be more selective
• Sex that invests less in offspring rearing will
  compete for access

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Role Reversal

• In species like the seahorse and pipefish, males
  carry eggs and females compete for access

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Sex-determination in Humans

• Sex Determining Region of Y (SRY)
• ? Testes
• ? Androgens (Testosterone)

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Hormonal Effects
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Hormonal Exposure and Cultural Experience are
Inextricably Linked in Humans
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Resolving Hormonal Contributions to Sex
Differences in Behavior

• Animal models
• Hermaphroditism having both testicular and
  ovarian tissue

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Resolving Hormonal Contributions to Sex
Differences in Behavior

• Animal models
• Hermaphroditism having both testicular and
  ovarian tissue
• Psuedo-hermaphroditism External genitalia
  opposite of genetic sex
• Androgen Insensitivity Syndrome (AIS)

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Hormonal Contributions to Sex Differences in
Behavior

• Animal models
• Exposure to synthetic hormones in humans (e.g.,
  DES)
• Psuedo-hermaphroditism
• Androgen Insensitivity Syndrome (AIS)
• Congenital Adrenal Hyperplasia (CAH)

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CAH

• Autosomal recessive gene (CYP21) maps to HLA
  region of 6p
• Affects 1/10,000 to 1/15,000 births
• Metabolic, deficiency in the adrenal enzyme, 21-OH

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CAH Severity Continuum

• Salt-Losers exposed to highest levels of
  androgens
• Simple-Virilizers exposed to somewhat lower
  levels of androgens
• Nonclassic CAH not virilized at birth

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Treatment

• Detection 20 US states screen newborns.
  Prenatal detection and treatment is possible
• Mineral replacement for salt losers
• Corticosteroids
• Surgery for virilized females

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Servin et al. (2003)

• Why did they do this study?
• Sample?
• What was their major outcome measure?
• What was their major finding for this outcome?

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Thought to reflect socialization processes
Gendered and reflects childrens interests
Evolutionarily significant
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Choices in Girls with and w/o CAH
Based on sample of 52 girls age 2-10, Servin et
al. (2003)
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Berenbaum Hines (1992)

• Girls and boys age 3-8 years with CAH (N26/11)
  or without CAH (N15/18)
• Toy play paradigm
• Girls Toys dolls, kitchen supplies, toy phone
• Boys Toys cars, blocks, Lincoln Logs

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Play Time With Boy Toys
Berenbaum Hines (1992)
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Play Time With Girl Toys
Berenbaum Hines (1992)
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Hormonal or Socialization?

• Our data do not lend themselves to any strong
  conclusions on the effect of socialization. p.
  447
• Parent Effects
• Toy play with parents
• Parent wishes
• Parental reinforcement parents of CAH girls
  more likely to reinforce girl toy play than
  parents of non-CAH girls (Pasterski et al. (2005)
  Child Develop)
• Reaction to virilization similar behavioral
  outcomes in early and late surgically treated

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Other Research on CAH

• Spatial ability
• Personality, interests, and preferences
• Sexual interest, fantasy, and behavior

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Long-term Outcome in Women with CAH
Based on 38 women with CAH and 30 w/o CAH
Meyer-Bahlburg et al. (2003)
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Other Research on CAH

• Spatial ability
• Personality, interests, and preferences
• Sexual interest, fantasy, and behavior
• Occupational choice ???

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Summary on CAH

• On some gender-role behaviors, females with CAH
  show average responses intermediate to girls and
  boys not having CAH
• On some aspects of sexual orientation, females
  with CAH are again, on average, intermediate
• On gender identity, girls with CAH dont appear
  to differ much from girls not having CAH (i.e.,
  dont appear to have higher rates of gender
  dysphoria)
• Questions
• Do these observations implicate hormonal
  influences on sexual dimorphisms in behavior?
• If it did, would existence of hormonal (or
  genetic) influences justify differential
  treatment of males and females?

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Treatment Controversies in CAH

• Prenatal treatment
• Must be started w/i first 6-7 weeks of gestation,
  prior to dx of CAH status of fetus
• 7/8 fetuses would receive unneeded and
  potentially harmful treatment
• Surgery to match rearing sex (intersex)
• Risks/benefits
• When? Who decides?

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Optimal Gender Policy

• the conclusion that emerges is that sexual
  behavior and orientation as male or female does
  not have an innate, instinctive basis. the
  evidence of hermaphroditism lends support to a
  conception that, psychologically, sexuality is
  undifferentiated at birth and becomes
  differentiated as masculine and feminine in the
  course of the various experiences of growing up.
• John Money (1955)

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John/Joan
The case of sex reassignment demonstrates
that gender dimorphic patterns of rearing have an
extraordinary influence on shaping a childs
psychosexual differentiation and the
ultimate outcome of a female or male gender
identity. Money Ehhardt (1972)
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