Sex differences.

advertisement
Sex differences
Messinger
Gender film clips
Bonobo
Biology's role



“Experiments with nonhuman primates
show that administering testosterone to
female fetuses late in gestation yields
more typically masculine behavior.”
Placement of rat fetuses in utero
influences sex-typed behavior
Many sex differences are continuous, not
categorical

E.g. estrogen and testosterone
Sex Differences in Early
Infancy

“girls show stronger visual
preferences for a doll (i.e., an object
with human attributes) than for a
toy truck
• (Alexander, Wilcox, & Woods, 2009)…

boys shortly after birth show
stronger visual preferences for a
mechanical mobile than for a face
• (Connellan et al., 2000)”
Alexander, G. M., & Wilcox, T. (2012). Sex Differences in Early
Infancy. Child Development Perspectives, 6(4), 400-406. doi:
10.1111/j.1750-8606.2012.00247.x
Feedback

Between physical and social features
Male newborns

‘Less responsive to social stimuli



less able to maintain eye contact
Greater difficulties in maintaining
affective regulation
Smile less and display more irritability,
crying, facial grimacing, and lability of
emotional states


more rapid buildup of arousal
engage in less self-comforting’
• Weinberg et al., p. 175
Face-to-face
Joy
Interest
Anger
Look @ Mom
Look @ Object
Neutral/Positive
Vocalizations
Fussy Vocalizations
Boys
.26
.55
.07
.42
.35
.13
Girls
.16
.68
.03
.35
.45
.06
.09
.04
(Weinberg et al.)
Mothers more likely to
talk to
 engage in face-to-face interaction
 hold and touch
 their male infants


possibly in an attempt to soothe them
Differential social
expectations
Pervasive: TV, media
 Experimentally demonstrated
 Define normative expectations of
everyday behavior and
 Define boundaries of acceptable
behavior
 At the most intimate and the most
mundane levels

Maccoby

"By and large, the daily routines of
family life do not have much impact
on the strong tendency of children
to separate into same-sex groups,
and probably not on the distinctive
activities enacted by male and
female groups," Maccoby said.
Gender segregation

Research on gender typing in
individuals is inconclusive
Clustering of gender-typed
characteristics weak
 Relations to family characteristics weak


Same-sex groupings predominate
From 3 – 12,
 Cross-cultural phenomenon

Martin and Ruble
• What age do infants understand gender?
• How stable are gender roles?
– Maccoby (2002)
• Longitudinal studies of gender role stability
– Studies suggest some level of stability
– Lack of longitudinal data with enough detail
Martin, C. L., & Ruble, D. N. (2010). Patterns of Gender Development
Annual Review of Psychology (Vol. 61, pp. 353-381). Palo Alto: Annual
Reviews.
Constructivist argument
Innate gender-specific proclivities
 Lead to same sex segregation
 Which creates gender-specific
socialization
 Children create themselves playing
with each other


IS THIS POSSIBLE?
Same-sex groupings

Boys
 Larger groups
 More
conflict/competition
 Cohesiveness
 More autonomous
from adults
Differential

Girls



Smaller, more
dyadic
Less conflict, more
responsive
Less goal-oriented,
more intimate
exposure to these groups
influences individual behavior
Dynamic system approach
to gender research

Long term changes and short term
interactions.
Ande Bustamante
Lynn Martin, C., Fabes, R. A.,
Hanish, L. D., & Hollenstein, T.
(2005). Social dynamics in the
preschool. Developmental
Review, 25(3–4), 299-327. doi:
http://dx.doi.org/10.1016/j.dr.20
05.10.001
Example of Dyadic SSG
“Fig. 4A represents the state space
pattern that might be seen for a socially
competent boy who is solely attracted to
other socially competent children. “
“Fig. 4B illustrates a pattern based on sex
similarity. In this case, the events
represented on this boy’s state space
illustrate that he is seen interacting only
with boys and it does not matter what
type of social behavior they tend to
display. “
“Fig. 4C depicts the landscape for a
socially competent boy whose state space
is shaped by both similarity on social
behavior and on sex. The events cluster in
the region of socially competent boys. If
this pattern occurred, it would suggest
that behavioral similarity matters but only
in consideration for same-sex peers.”
Sex-Segregated
Interactions
Behaviorally Similar
Interactions
Cross-sex friendships
Pre-school
 Elementary school
 Middle school
 High school / Adolescence …

Change

12th grade
Boys 5 hrs a week w girls.
 Girls 10 hrs a week w boys.


Larger network of other-sex friends
increases odds of romantic
relationship
What about the development
of ASD?
Messinger, D. S., Young, G. S., Webb, S. J., Ozonoff, S.,
Bryson, S. E., Carter, A., Carver, L., Charman, T.,
Chawarska, K., Curtin, S., Dobkins, K., Hertz-Picciotto, I.,
Hutman, T., Iverson, J. M., Landa, R., Nelson, C. A.,
Stone, W. L., Tager-Flusberg, H., & Zwaigenbaum, L.
(2015). Early sex differences are not autism-specific: A
Baby Siblings Research Consortium (BSRC) study. Mol
Autism, 6, 32. doi: 10.1186/s13229-015-0027-y
Proportion ASD
Relative risk of ASD = 3.18
Sex by domain
not affected by group
Repetitive Behaviors
Social Affect
Sex by subtest
not affected by group
Conclusion


Sex differences in ASD prevalence
No sex differences in overall symptoms or
cognition
• Boys (higher RRB) and girls (higher language)
with ASD differ in specific performance areas
• These sex differences exist in ASD, non-ASD,
low-risk


Results are consistent with recent reports
Sex differences that appear in children
with ASD may not be ASD-specific
Extreme male brain
theory of autism
Baron-Cohen
Empathizing
(theory of mind)

“Empathizing is the
capacity to predict
and to respond to the
behavior of agents
(usually people) by
inferring their mental
states and
responding to these
with an appropriate
emotion.”
Systemizing

“Systemizing is the
capacity to predict and
to respond to the
behavior of
nonagentive
deterministic systems
by analyzing inputoperation-output
relations and inferring
the rules that govern
such systems.”
Females and males



“At a population level, females are stronger
empathizers and males are stronger
systemizers.
The ‘‘extreme male brain’’ theory posits that
autism represents an extreme of the male
pattern (impaired empathizing and enhanced
systemizing).
Specific aspects of autistic neuroanatomy may
also be extremes of typical male
neuroanatomy.”
You can be high in both… or
low in both

Higher on graph
– more
empathizing


Lower – less
empathizing
More to right –
higher
systemizing

More left – less
systemizing

Autistic
people show
lowest
Empathizing
(empathizing
minus
systemizing)
AS/HFA>Male>Female
AS/HFA>Male>Female
Sex differences attenuated
in ASD….
Baron-Cohen, S., Cassidy, S., Auyeung, B., Allison, C.,
Achoukhi, M., Robertson, S., Pohl, A., & Lai, M.-C.
(2014). Attenuation of Typical Sex Differences in
800 Adults with Autism vs. 3,900 Controls. PLoS
ONE, 9(7), e102251. doi:
10.1371/journal.pone.0102251
Homosexuality as a
Discrete Class.

Previous research on the latent structure of sexual orientation has
returned conflicting results, with some studies finding a dimensional
structure (i.e., ranging quantitatively along a spectrum) and others a
taxonic structure (i.e., categories of individuals with distinct
orientations). The current study used a sample (N = 33,525) from the
National Epidemiologic Survey on Alcohol and Related Conditions
(NESARC). A series of taxometric analyses were conducted using three
indicators of sexual orientation: identity, behavior, and attraction. These
analyses, performed separately for women and men, revealed low-baserate same-sex-oriented taxa for men (base rate = 3.0%) and women
(base rate = 2.7%). Generally, taxon membership conferred an
increased risk for psychiatric and substance-use disorders. Although taxa
were present for men and women, women demonstrated greater sexual
fluidity, such that any level of same-sex sexuality conferred taxon
membership for men but not for women.

Norris, A. L., Marcus, D. K., & Green, B. A. (2015). Psychological Science. doi:
10.1177/0956797615598617
Same-sex relationships


Normative challenges in the context of
disapproval/restriction
Female gender identity / relationships


Male gender identity / relationships


Non-linear course
More-linear course
Same-sex and mixed-sex parenting
indistinguishable
Female Bisexuality From Adolescence to Adulthood:
Results From a 10-Year Longitudinal Study. Lisa Diamond

3 conceptualizations of bisexuality
1. “Transitional phase”
2. Third type of sexual orientation
3. Heightened capacity for fluidity

Present study


79 non-heterosexual women
10 years, 5 assessment points. At each:
• Label self sexual identity
• Lesbian, bisexual, “unlabeled”
• % daily attractions that are same-sex
• #of sexual contacts with men & women
(since last assessment)
Nayfeld
Sexual
Attractions
•Lesbian women had
significantly higher
same-sex attractions
•Same-sex attractions
declined significantly
among lesbians only
•Women who gave up
bisexual/lesbian IDs
still reported bisexual
patterns of attraction in
T5
Nayfeld
Sexual Behavior





Consistent decline in same sex behavior
among all women
NOT matched by a parallel decline in same-sex
attractions
In 1995, behavior evenly distributed
By 2005, bimodal distribution (either
exclusively with men or women)
By 2005, most women involved in long term
monogamous relationships.
70% of T5 lesbians, 89% of bisexuals, 85% of
unlabeled women, 67% of heterosexuals

By 2005, 60% of T1 lesbians had had sexual
contact with a man, and 30% had been
romantically involved with a man
Resolved by change in identity to
bisexual/unidentified
Nayfeld
Discussion




•
•
Results consistent with both “third
orientation” and “heightened fluidity”
models, not “transitional stage” model
Bisexuality as stable pattern of attraction
to both sexes, with balance varying based
on personal and situational factors.
Identity change more common than
identity stability
ID change reflects shifting experiences
Adopt labels consistent with relationship status
Seek to maximize fit with own prevailing pattern
of attraction/behavior
Nayfeld
Bonobo chimps (Pan
paniscus)

The species is
distinguished by an
upright gait, a matriarchal
and egalitarian culture,
and the prominent role of
sexual activity in their
society.


one of the two species
comprising the
chimpanzee genus, Pan.
The other species in
genus Pan is Pan
troglodytes, or the
Common Chimpanzee.
http://en.wikipedia
.org/wiki/Bonobo
Bonobo videos
http://www.youtube.com/watch?v=
eubDSQrFako sex, walking, wonder
 http://www.youtube.com/watch?v=
Q_izpq0Ar-Y Evolution: "Why Sex?"
[Chimps vs. Bonobos], evolutionary
speculation

Download