Sex and Gender Flashcards
Three reasons for focusing a chapter on gender
- sexual dimorphism in our species provides a natural control group for some interesting cognitive adaptations - examining male and female cognitive differences - better appreciate the design - overcome instinct blindness
Ex. men rely on cognitive map, women rely on landmarks - People who otherwise insist on setting aside the nature vs. nurture issue will fall into old habits when talking about gender development, suggesting that sex differences must be “learned” or “cultural” rather than “biological.”
- adaptations of men as a group and of women as a group allow us an opportunity to consider the fit between adaptations and the adaptive problems they solve.
Sex:
The observable biological markers that are used to categorize males and females, including sex chromosomes and external genitalia
Gender:
An individual’s felt gender identity and the ways the gender identity is portrayed, including dress, mannerisms, speech, social roles and occupation.
Gender Roles in the EEA - Males
hunting - hunted in coalitions
Projectile weapons- spatial-cognition tasks - had to travel more
Males explore more even in childhood
Spatial navigation over large areas
Coalitional psychology
Use of projectile weapons
Exploration of large range - even in childhood
Gender Roles in the EEA - females
foraging, gathering plant matter - up to 60% of calories
Women only source of calories for a newborn baby who was breastfed exclusively - lasting longer in EEA
Make fine perceptual discriminations - color, texture - ripe fruit
Remember the location of plants
Fine discrimination of color
Fine discrimination of texture
Fine motor skills
Sex Differences - complex adaptations
In general, we should expect complex adaptations to be universal.
Most variation in human genomes can be accounted for either by genes that have little or no effect on the phenotype or by relatively recent (usually deleterious) mutations.
The sexes are an exception to this rule
sex differences - different morphs
Males and females are two different morphs (versions) of the same species just as the caterpillar and the butterfly are
each of which shows a coherent suite of complex adaptations, and the genes that underlie the complex adaptations are universal to every individual in the species
A man has all of the genes that underpin the development of ovaries, fallopian tubes, and a uterus; he got these genes from his mother and his father, and he will pass these genes on to his daughters and his sons
Men and women have a suite of adaptations that all work in tandem to optimally take advantage of their reproductive strategy
adaptions to take advantage of their reproductive strategy
adaptations include morphological (internal and external genitalia), physiological, endocrinological, cognitive, and emotional adaptations.
Sex is defined, biologically, in terms of
gamete size
In any species that produces two gamete sizes, males produce the smaller gamete (sperm), and females produce the larger gamete (the egg).
what happens when fertilization is internal to the female?
If fertilization is internal to the female, as it is in mammals, the female becomes the choosier sex since making the larger gamete means making a larger investment, and internal fertilization leads to a larger investment in offspring
Male makes a small reproductive investment - more offspring than female
Changes his reproductive strategy
Adaptations work together to optimize a given strategy
From conception sex differences
Males more likely to be miscarried/ abort
Males more vulnerable to physical and mental abnormalities
Males more likely to die shortly after birth
Boys more active in utero than girls
Physical Size and Strength
Early life - similar size
Girls: smaller, lighter, less muscular from birth, healthier and more mature at birth
Childhood: boys and girls - similar growth rates - boys stronger
Motor Skills
Girls: more coordinated at birth
Boys: by 5 - jump farther, run faster, throw ball fathers
Girls at 5 - fine motor and balance better, skipping and hopping
Middle childhood:
girls better at fine motor - penmanship and drawing, balance and agility
Boys better at gross motor skills, strength
Gender gap increases through middle childhood and greatly after puberty
how does formal training affect motor skills
Exposure to formal training - little development on motor development for typically developing children
Verbal Skills
Girls stronger in language development -
girls in infancy:
more speech sounds,
use words earlier,
larger vocabularies,
more grammatical complexity,
superior verbal memories
Quantitative Skills
Girls: higher grades in math but boys perform better on high-stakes tests on math like SAT
Males stronger in some aspects of visual-spatial processing - emerges at 3-4yrs and more substantial during adolescence
Girls better at computational problems in math and boys better at mathematical reasoning
Social Skills
After birth girls: orient towards people more than boys, maintain eye contact longer, 3m- more face to face communication
12-20m girls more empathy
Consistent with sex differences in adulthood - except anger women experience emotions more intensely, have more intimate friendships, more empathetic towards friends, make more eye contact, smile and laugh more
Spatial Skills - EEA
Men use different navigation strategies and have specialized spatial reasoning skills
Bc - due to selection pressures resulting from the task of hunting: Hunters who could track animals over long distances and then return home easily and safely could increase their fitness
women’s gathering tasks in the EEA may be associated with better color and texture discrimination, fine motor skills, and memory for landmarks.
Spatial Skills - preschool
Preschool boys better at spatial rotation - spatial transformations, 3d spatial reasoning
Continues through adulthood
boys are better at navigating what ?
better at navigating real and virtual environments, making maps and interpreting maps
recreate town layout
At every age - boys better than girls at a task that required them to re-create a towns layout after a walk through
What affects performance in girls on spatial rotation tasks?
GIrls who have abnormally high prenatal androgen levels - superior performance on spatial rotation tasks compared to other girls
Girls better at remembering the locations of specific objects among an array of various objects - evident at 8yrs
Shown an array and asked to recall which objects appeared where - girls better at recalling the identity of the objects and their locations
Selection pressures females faced during the EEA - gatherers - fine perceptual discriminations and remember location of plants
Women menstruating - spatial skills
When estrogen levels are at their highest - perform better on cognitive tasks associated with superior female performance
Estrogen levels at monthly low - better at tasks associated with male superior performance - spatial rotation
Aggression
Boys more physically aggressive - from early childhood on more likely to use physical aggression
Men commit 90.5% of murders and 79% of adults assaults in US
Girls more likely to engage in relational aggression
Relational Aggression:
The attempt to harm others by damaging social relationships. This type of aggression may take the form of gossip, spreading rumors, or ostracism.
Interests and Free Time
Preschool -
boys interact with other boys - play with more active and constructive toys
Girls - spend time among other girls and play with quieter toys associated with fine motor skills
Boys more likely to engage in rough and tumble play
Girls more like to pretend parent
rates of playing with same sex playmates
Age 4, children spend 3 times playing with same-sex playmates compared to opposite-sex playmates
Age 6, spend 11 times more time with same sex
Playground play
Boys cover more territory than girls - variety of cultures - boys have larger territories of exploration
Activities boys select - more visual spatial -facilitates the development of spatial cognition in boys
Children who play with manipulative activities score higher on spatial cognition tasks
spatial cognitive abilities and practice
Adult females, there is a relationship between spatial-cognitive abilities and the frequency with which an individual engages in activities that demand spatial-cognitive skills
why do boys learn more about spatial cognition?
Boys learn more about spatial cognition because boys are attracted to the kinds of activities that lead to its development. This is good engineering, designed by natural selection.
Veveret monkeys - similarites in sex-defined preferences for toys
vervet females spent more time playing with the girl-preferred toys, while the males showed the opposite pattern, and there was no sex difference in playing time for the neutral toys
sex differences in toy preferences develop even in the absence of human culture
Early sex differences are seen cross-culturally.
All over the world, girls spend more time doing household chores and contributing to childcare, and boys spend more time unsupervised by adults
Boys’ activities take them farther from home, while girls are more likely to be found close to home
Self-Esteem domains for each sex
men had higher: athletics, appearance, self-satisfaction
Women had higher in: morality and ethics, conduct
self-esteem and appearance in girls in adolescence
Girl’s satisfaction with their appearance decreases through adolescence, and this negative self-assessment continues into adulthood - doesnt happen to boys
self esteem and boys in adolescence
sex difference in self-esteem in the athletic domain increases during adolescence and this increase is driven mostly by a decrease in girls’ estimates of their athletic ability
Boys’ self-esteem in athletics is also higher than girls in a number of sub-domains including coordination and endurance
high esteem for girls in conduct
high self-esteem in the behavioral conduct domain believe that their behavior is socially appropriate. This domain is particularly relevant in a school classroom, where one’s behavior is often publicly assessed with respect to its appropriateness
morality and ethics domain includes both adherence to religion and the treatment of others when faced with a moral dilemma. Women value this domain more than men do, and they appraise themselves more favorably in this domain than men do
Relative Life Expectancy
males die at a younger age than females - the difference is around five years on average.
Evidence consistent with the idea that men have a much greater variance than women in reproductive success
men have a much greater variance than women in reproductive success
mitochondrial DNA studies - DNA in the extra-nuclear organelle of each cell.
This DNA comes to you only from your mother; there is no sexual recombination and no contribution from your father
Men have Y chromosomes that they always get from their fathers only
Greater diversity of DNA in the mitochondrial DNA (mom’s DNA) than in Y chromosome DNA
Consistent with the idea that there is greater variance in reproductive success in males than females
A man can increase his reproductive success by having more mates, but men in general run the risk of losing the game completely by having no offspring
competition and related risk-taking are worth it for males but not for females
greater potential payoff for any male strategy that might attract a mate, and therefore males are willing to accept the risk in order to vie for this greater payoff.
male displays of physical acumen (think extreme sports) may have been attractive to females in the EEA or may have impressed other males enough to raise an individual’s status, indirectly leading to greater mate value, but it also leads to fatal accidents
Accidents are the leading cause of death in young males aged 1–24 and the second highest cause of death in adult males aged 25–44
Daredevil behavior is a result of psychology awarded to males in the EEA - high risk for reproductive success
risks for males may be physiological as well as behavioral:
Males with higher testosterone levels are more attractive to females but testosterone suppresses their immune system, leaving men open to the risk of exposure to pathogens.
the greater risk associated with male behavior and male hormones, the sex difference in life expectancy results from pleiotropy - occurs when a single gene has effects on more than one phenotypic trait
good explanation for senescence in general and for the sex difference in senescence. If a single gene affords a great advantage to someone (in terms of reproduction) at the age of 20 but is associated with a deleterious effect at age 80, that gene will be selected for more strongly than it is selected against, regardless of how damaging it is at age 80
Genes that are potentially beneficial early in one’s reproductive years are resistant to “weeding out” despite deleterious effects that occur after the age of reproduction.
Men more vulnerable to the senescent effects of pleiotropic genes
Sex difference in life expectancy in polygamous species even in the zoo
The Development of Sex and Gender
Development of one sex or the other is set in motion when the sex chromosome from the father is delivered to the mother’s egg, creating the complete genome.
A fertilized egg (and every subsequent cell in that developing individual except gametes) has 46 chromosomes, comprising 23 pairs. Twenty-two of those pairs are autosomes, the name for chromosomes that are not sex chromosomes.
Autosomal pairs - chromosome from the mother and father correspond and have the same set of loci
23rd pair is sex chromosomes
default development of external genitalia is
female:
Without the presence of androgens early in fetal development, the baby will have a female external appearance.
Masculinization relies on the production of relatively high concentrations of male hormones
We know this because if you remove the gonadal tissue of a fetal rabbit, the rabbit develops a visibly female body complete with vagina, uterus, and cervix, regardless of its chromosomes
Y chromosome
typically moves the developing fetus off of the default path and onto the path to masculine development, and this is just about the only thing the Y chromosome does
Smallest chromosome - not a lot of room for many genes
SRY Gene
The gene on the Y chromosome is usually associated with male development in mammals, SRY is an acronym for sex-determining region Y
Transcribed at 7 weeks of gestation
Creation of the Testis Determining Factor:
A protein that will trigger the development of the fetus’s testes in typical male development.
masculinization of body and brain
testes then produce and release androgens, including testosterone. These androgens masculinize the body and the brain.
masculinization of the genitals occurs in the middle of the second trimester and is dependent upon a surge in androgens at that point.
masculinization of the brain and the concurrent masculinization of gender identity takes place just prior to and around the time of birth and relies on a new surge of androgens at that time.
how do Sex hormones, both androgens and estrogens affect neurons
affect neurons by manipulating the onset and rate of growth of axons and dendrites - affect cognition and behavior
Receptors are in hippocampus, hypothalamus, the amygdala, the limbic system, and the cerebral cortex, presumably because all of these areas are optimized differently in each sex
does not mean that the Y chromosome “determines” sex or gender
1 - even though the SRY gene starts a series of events that lead to masculinization, lots of genes on lots of chromosomes are involved in the development of the penis, testes, dense musculature, deep voice, facial hair, receding hairline, and the suite of cognitive adaptations that are characteristic of men (just as many genes underlie the suite of female adaptations)
2 - There are conditions, such as androgen insensitivity syndrome, described in more detail later in this chapter, in which a person has an SRY gene but instead develops female morphology and a female psychology.
Environmental Estrogens and Sex Development
development of male external genitalia depends on androgens and on the relative concentrations of androgens and estrogens
Increase in male genital malformation over last 4 decades - possibly due to environmental estrogens ex. Micropenis, undescended testicles, hypospadias - failure of the penile shaft to develop completely
Environmental estrogens - herbicides, pesticides and polystyrene
mimic estrogens—estrogen receptors respond to them as if they were estrogens— or they act as androgen antagonists and interfere with the functions of testosterone and other androgens.
. The extent of the maldevelopment depends on the timing, and exposure during the first trimester of pregnancy is associated with the most profound effects.
Climate Change and Sex Ratios
chromosome-based mechanism underlying sex development in humans is seen in most mammals as well
But different schemes of sex development in different species
Birds - female has two different sex chromosomes - male has two copies of same chromosome
Worm - embryonic period in another worms mouth - male
Reptiles - chromosomes are not different in the two sexes
Turtles - temp of egg determines sex - some control over gestational temp - climate change can cause sex ratios that cannot be controlled
Warm years - most extreme ratios - lay eggs earlier for cooler incubation - control egg laying date - but cannot control for climate change
Temp at conception effects sex ratio in cows
Sex Differences Across Cultures
Greater male variance in reproductive success has implications for child rearing
greater sex differences: males in polygynous species are larger and more aggressive, reflecting the greater payoff available to those who successfully out-compete other males.
More polygyny a culture has the more boys were taught to exhibit aggression, fortitude and industriousness - correlation btw max harem size (greates number of wives a man can have) and the extent to which boys are trained to be competitive
Polygynous societies, girls are more likely than boys to be taught to be industrious and obedient and to show sexual restraint
The Trivers-Willard Hypothesis
suggests that in populations where males have greater variance in reproductive success than females do, then mothers who are healthier and better resourced than average should have sons, while mothers who are less resourced than average should have daughters
A mother who is very well resourced might have an opportunity to have a great number of grandchildren if she has a son, but a mother who is poor or unhealthy risks having no grandchildren if she has a son.
Her better strategy is to have a daughter, since daughters will likely have some offspring, and the expected value is the population average.
The Trivers-Willard Hypothesis evidence
Evidence in red deer, horses and wasps
mothers in better condition have a male-biased sex ratio among their offspring while mothers in poorer condition have a female bias among their offspring
Evidence in humans
children born to people on the Forbes billionaires list are 60% male, which is significantly different from the general population
Venezuala showed that families who didn’t have access to medical care or who were illiterate had more daughters, while higher education levels were associated with male-biased sex ratios in offspring
with a large enough data set, there is evidence of a male-biased sex ratio among higher SES mothers and a female-biases sex ratio among low SES mothers, but the effect size is small
Another prediction that comes from the Trivers-Willard hypothesis
in addition to a sex ratio difference between richer and poorer mothers, the wealthiest families would be expected to invest more in their sons than in their daughters, while poor families would be expected to invest more in their daughters
A wealthy family might have an opportunity for tremendous payoff if a son becomes one of the few males who is fathering the next generation. However, if the sons of poorer families are unlikely to have an opportunity to have a family, an investment in daughters is a better bet
Kenya and nursing - evidence for trivers
Some supporting evidence in humans
mothers in an agricultural village in Kenya found that low SES nursing mothers produced higher quality milk (based on nutritional content) when nursing daughters compared to sons. The opposite was true for the highest SES nursing mothers in this population
higher SES mothers invested more in sons that daughters, while the opposite was true of lower SES mothers.
effect was significant for a number of measures including whether or not the child was breastfed, duration of breastfeeding, birthweight and inter-birth intervals
sons in high SES families complete more years of education than daughters in those families, while daughters in low SES families complete more years of education than do sons in those families
supports the idea that sex ratios at birth and sex-related differences in parental investment can differ across higher SES and lower SES families
Puberty
Puberty is a coordinated set of changes that leads to sexual maturation and entry into the sexually reproductive years. A series of dramatic bodily transformations are associated with puberty in early adolescence
Menarche
The point in female puberty at which the first menstrual bleeding occurs.
Spermarche
The point in male puberty at which sperm is first ejaculated.
when do hormonal increases that underlie puberty start
modern society, the hormonal increases that underlie puberty, such as the increase in growth hormone (GH) and thyroxine, begin as early as 8 or 9 years of age.
As puberty begins for boys
testes release testosterone in unprecedented amounts, leading to the development of primary and secondary sexual characteristics: increased muscle mass, facial hair, and a deepened voice, for example
body fat decreases in boys
boys, the first sign of puberty is the growth of the testes. This is followed by the emergence of pubic hair and then, around the age of 12, the growth of the penis.
It is not until the development of these primary sexual characteristics is complete that a boy starts his growth spurt.
The masculinization of the boy’s voice (as the larynx enlarges and the vocal cords lengthen) begins during the growth spurt and is not typically complete until puberty is complete
puberty beginning for girls
girl’s ovaries begin to release large amounts of estrogen, leading to the development of breasts, growth and maturation of the uterus, and a feminine pattern of fatty deposits.
Body fat increases in girls, and is increasingly deposited on the arms, legs, and trunk
Androgens released from the adrenal glands (above each kidney) lead to increased height and the growth of pubic and underarm hair.
Menstruation - androgens released from the adrenal glands (above each kidney) lead to increased height and the growth of pubic and underarm hair.
3- to 4-year period is characterized by the beginning of breast growth, a growth spurt, menarche, pubic and underarm hair development and the completion of breast maturation, in that order
Menstruation doesn’t occur until after the growth spurt
readiness to carry a child is further ensured by a 12- to 18-month period of sterility following first menstruation during which the ovaries do not produce eggs with each cycle.
The age of first menstruation
varies from society to society and has changed over historical periods. In North America, the average age at menarche is about 12½.
growth spurt, leading to a dramatic increase in height, is underway at age 10 for girls and age 12½ for boys in a North American sample
average girl is taller than the average boy between the ages of 10 and 14.
Girls are typically finished growing in height at age 16 and boys at age 17½
During this growth spurt, body proportions change in the two sexes: boys’ shoulders grow wider than their hips, while girls’ hips grow wider than their shoulders
growth spurt
underway at age 10 for girls and age 12½ for boys in a North American sample
average girl is taller than the average boy between the ages of 10 and 14.
when do boys and girls finish growing
Girls are typically finished growing in height at age 16 and boys at age 17½
change in proportion during growth spurt
During this growth spurt, body proportions change in the two sexes: boys’ shoulders grow wider than their hips, while girls’ hips grow wider than their shoulders
when do children know their gender
Between their second and third birthdays, most children come to know which gender group they belong to.
gender characteristics at 2-3
Even at this age, girls are more compliant, sensitive, relationally aggressive, fearful, and dependent,
whereas boys are more active and physically aggressive
traditional gender-schema theory
gender schemas and accompanying expectations about male and female behavior does not develop in children until their own gender identity has developed.
That is, until a child could label themselves as “girl” or “boy” at around the age of 3, they were not expected to know anything about gender-specific interests, roles, or activities
clear evidence that very young children categorize male and female.
Infants appear to be able to tell the difference between the sexes using multiple perceptual cues although the capacity to make this distinction does not reveal what they understand about what it means to be male or female.
Infants discriminate between male and female voices as early as 6 months
between male and female faces before the first birthday
3- to 4-month-olds can discriminate between male and female faces using a habituation paradigm
habituated to a male face, they dishabituated to a female face, showing a looking-time preference for females. However, if they were habituated to a female face, they did not dishabituate to a male face - preferred to look at female faces
opposite pattern was true for babies whose primary care-giver was male.
Opposite was true if primary caregiver eas male
Poulin-Dubois - evidence of very early gender-defined expectations.
Toddlers as young as 2 years old were asked which of three dolls would act out various activities.
One of the dolls was male, one was female, and one was a toy monkey, meant to be a gender-neutral option.
The activities were typically male activities, typically female activities, or activities that both men and women are likely to do. Examples were shaving, fixing a car, holding a baby, vacuuming, and sleeping.
Two-year-old girls, but not 2-year-old boys, preferred the male doll to perform masculine activities and the female doll to perform the feminine activities. In other words, 2-year-old girls revealed an understanding of gender stereotypes
Looking time measure - test for understanding of gender-typed behavior
18m - saw feminine items and masculine items, male and female faces
Herd a gender neutral voice asking to look then the two faces appeared
Looked longer at female face when they had seen a feminine object on that trial and same with male faces
Serbin - 2yr olds looking toward 2 computer screens
One a man performed an activity while a woman on the other screen performed the same activity
Masculine or feminine or neutral activities
Looked longer when a man performing feminine activities - expectations had been violated
By 3 gender
- use gender terms in speech, categorize and label their own and others sex - increases with accuracy and determination until around 4
Four-year-olds - gender enforcers
are adept at categorizing the gender cues of their local culture, associating toys, tools, activities, occupations, and colors with one sex or the other
telling children and adults what they can and cannot wear, and what occupations they can and cannot hold, based on gender
demonstrate the gender-appropriate response to peers
Gender Typing:
The developmental process by which children come to adopt their culture’s markers of gender, including style of clothing, choice of activities, manner of speech, and values.
more tolerant of violations of gender expectations when
between 5 and 9 years of age. This gender enforcement can differ cross-culturally and is more flexibly in more politically liberal communities
school years, children have a set of expectations regarding the characteristics of each sex
They think girls are “gentle,” “sympathetic,” and “dependent,” and boys are “tough,” “aggressive,” and “rational”
mathematics, athletics, and mechanics as masculine academic areas and reading, art, and music as feminine
middle childhood, children can be fairly tolerant of a girl who crosses gender lines
crosses gender lines by, say, playing sports or excelling at math but are harsh critics of a boy who crosses gender lines by playing with dolls or wearing feminine clothing, often responding with moral outrage as if a moral rule has been violated
9 and 12, boys - gender expectations
Between the ages of about 9 and 12, boys increasingly adhere to gender expectations during a time when girls relax their adherence to feminine expectations
period of relative gender freedom is not universal:
girls do not experiment with masculine sex roles in cultures where the division of sex roles is greater than in North America. This period of gender freedom for girls ends in early adolescence, a period of intensifying attitudes toward gender norms
Gender Socialization Theory
gender roles, norms, and behaviors are learned via the same general learning principles that underlie other types of social learning: reinforcement, observation and imitation
gender develops when children are socialized by parents, peers, and the culture at large
Children are said to be socialized by observing and imitating role models of one sex or the other and having gender-conforming behaviors enforced.
One mechanism of gender socialization, according to this view, is the way parents convey their expectations regarding gender-appropriate behavior either explicitly or implicitly.
North American parents tend to provide gender-specific…
(trucks and tools for boys, dolls and kitchen sets for girls) even before their children are old enough to verbally request these toys
Parents assign different household chores to boys and girls, consistent with gender expectations
One naturalistic observation study conducted in a science museum showed that parents were three times more likely to explain the science exhibits to their sons than to their daughters
test how adults treat infant boys and girls - lots of evidence for this theory is actually based on adults
adult participants were introduced to an infant who was either dressed as a boy and introduced as a boy, dressed as a girl and introduced as a girl, or dressed in neutral clothing and introduced without reference to the infant’s sex
adult who was not a parent
Both men and women were more likely to give the alleged girl the doll rather than the football and were less likely to give the boy the doll compared to the girl.
supports a socialization view of gender development
same blank-slate underpinnings as John Watson’s behaviorism - Fausto-Sterling (1985)
Fausto-Sterling (1985) contends that “the key biological fact is that boys and girls have different genitalia”
she argues, parents label the child pink or blue so that they can be socialized appropriately
emphasizes the complete gender plasticity of each infant, viewing newborn infants as “bi-sexual,” which is to say equipotent, with respect to gender.
According to this view, infants are then socialized to be male and female by those around them
Evidence in favor of gender socialization theory
Children observe same sex models more
Imitate same-sex models more
Gender is learned
Domain General learning - observation, imitation, reinforcement
The Reimer Twins : A Natural Test of Gender Socialization Theory
experiment to test the hypothesis that, at birth, babies are perfectly malleable blank slates with respect to gender
Bruce Reimer - typical boy
At the age of 8 months, Bruce’s penis was destroyed by a doctor during an attempted circumcision
Born with identical twin Brian
Money convinced the Reimer parents to raise Bruce, now called Brenda, as a girl.
When the twins were 13, their parents explained their history to them. Brenda almost immediately decided to live as a male and chose the name David
Separately, David and Brian both died by suicide as adults
Intersex
An umbrella term describing conditions in which an individual has some combination of chromosomal, genital, and brain development that is not typically male or female.
5-alpha-reductase deficiency:
A developmental condition caused by the failure of the body to produce sufficient levels of 5-alpha-reductase. Babies with male genotypes, or an XY chromosome configuration, will be born with typical internal male reproductive organs but female-appearing external genitalia.
