The Brain Friday and Monday January 8th and 11th The Nervous System Sexual Dimorphism o Rat rodent data vss Human data problem Men have bigger brains in humans but o Brain size not different according to body proportion differences o Burgaleta et al 2012 Brain size and intelligence w tasks Correlation in highly demanding spatial task b w brain size and performance No other significant effects did not correspond to intelligence o Luders et al 2009 Found difference in gray matter volume Women had more gray matter volume in several areas of brain Related to language processing o Even though finding significant differences Effect sizes extremely small Little practical significance Men and women lateralize differently o Wallentin 2009 review says no Sexually Dimorphic Nucleus SDN o In Hypothalamus o Larger in men sensitive to sex hormone o Size difference develops across life not present at birth o Nobody is completely sure as to what role it plays Lesion in gerbils Disrupt copulatory behavior Spinal Nucleus of the Bulbocavernosus o Rats 2008 Male sexual behavior in rodents no human data at all We don t know if related to gender Male rodents need in order to do typical male sexual behavior sperm count ejaculation mounting Strong role in influencing gender identity Hormones and Behavior Instability Premenstrual Syndrome PMS o Wide publicity Expectancy effects o Research fails to show relationship between hormonal variation and symptoms of PMS McFarlane s longitudinal studies Men and women keeping mood diary don t tell for menstrual cycle Wide age range Relationship between mood fluctuation did not go along with menstrual cycle No evidence to support PMS Gehlerts et al 2009 1 200 women Rural women ad urban women Urine samples everyday for two full cycles Kept mood diary Face to face interviews Premenstrual dysphoria disorder 1 3 met criteria Prevalence Ask women to recall menstrual difficulties 54 rate of PMDD o In clinical setting using retrospective Caplay 2004 Author harmful to women to diagnose medicated PMS PMDD Pharmaceutical would like us to diagnose Notes from empirical literature Women diagnosed with PMDD experiences distress from wide variety of sources o Far more likely to be in abusive relationships than other women o Given pill have not addressed real lifelong negative events that need addressing Labeling telling them they have something actually wrong with them o Self blame not getting out of situation Evidence in literature to suggest women that complain about PMS that s the excuse they use to talk about other stuff o Better off focus on other stuff than physiological event o Biological Explanation Symptoms Pain cramps Mood swings Bloating Tenderness of breasts Headaches Cravings of chocolate Hot flashes o How would we test this Two prong subjective and objective Woman subjective ratings Researcher measures biology hormone fluctuation Possibly Add woman across cultures Include men fluctuations w people in Partner someone who observes collateral general measure Testosterone Aggression Three possibilities o Testosterone causes increase in aggression Not supported in literature Dabbs et al studies Relationship between aggression and testosterone is complex Find that men and women both effected by testosterone and results are complex High testosterone related to impulsive antisocial rambunctious Not related to violent or aggressive Extreme end of Testosterone problems behaviors normal levels not Average levels of Testosterone across groups same Inmates college students no different in levels o Aggression causes increase in Testosterone Lab studies show increase in testosterone after S M dominant has testosterone rise submissive has aggressive behavior testosterone decrease Competition leads to increase in testosterone Athlete studies after competition testosterone levels have risen o Another factor mediates this relationships Example sensation seeking People higher in testosterone may be more prone to sensation seeking People who sensation seek may be more prone to aggression Risky behaviors in adolescents Kids more sensation seekers tend to pick peers that are also sensation seeking Culture Matters Western Cultures o View of blending of gender characteristics as deviant AIS as a condition different Other ways to think about it o Don t necessarily think of blending of gender as a bad thing o Native American two spirits Female born male essence Two spirits were more esteemed o Indian Hijras Men who wish to become women transwoman Power to confer fertility o Some African societies female husbands Public recognition as men sometimes take wives Male roles o Samoa fa afafine Men sexually attracted to men More than just orientation strong gender component Many of these individuals identify as this instead of identifying as one or the other