Psych 4543 Exam 2 Study Guide 2D 4D Ratio Ratio of length of second finger to fourth finger pointer ring finger Affected by exposure to androgens Originated during nineteenth century Early 20th century 200 men and 100 women showed sex differences in results 1980s Glenn Wilson women ratio and aggressiveness 1990 s John Manning sex differences in toddlers Digit Ratio the ratio between the length of the second index finger and the fourth ring finger Men tend to have longer ring fingers in relation to their index fingers and women tend to have similarly sized fingers or their index fingers may be slightly larger No proof Indicator of how masculine or feminine someone is not only physically but personality wise Increased testosterone doesn t lead to aggression 5 Alpha Reductase Deficiencies Rare genetic condition that affects male sexual development in the uterus and during puberty One X and one Y chromosome making them genetically male but a deficiency in dihydrotestosterone DHT production in the womb leads to external genitalia that appear female or ambiguous majority appear female Severely disrupts the forming of the normal male sex organs Often given the wrong gender label by doctor Increased muscle mass the voice deepens and penis and scrotum may enlarge Lack of facial body hair By adolescence or early adulthood roughly half of the cases will adopt their genetic role as male Affects infertility 5AR2 is involved in processing androgens hormones that direct male sexual development This condition is inherited in an autosomal recessive pattern Most parents show no symptoms Females don t show any signs affects Dominican Republic Disesase reports of turning into men at puberty They were referred to as guevedoces meaning penis at 12 years For the rest of their lives they had physical traits of men They later discovered this was due to a deficiency in the 5 Alpha Reductase enzyme In the 1970s 2 of births in the Dominican Republic had this condition Congenital Adrenal Hyperplasia affects girls rather than boys Result of too much testosterone exposure in the womb development of male external genitalia CAH girls scoring closer to boys in play preferences Amygdala Almond shape in limbic system Functions related to fear arousal and excitement Susan Pinker found that when women analyzed facial expressions they had more activity within the amygdala than men did Men thinkers women feelers Women had a more primary emotional reference No significant results Leonard Sax boys have difficultly connecting emotionally with literature due to the fact that emotional and language connections neurologically are based in less compatible parts of the brain specifically the amygdala than boys normally utilize such as the cerebral cortex Fine argues that these areas are interconnected Older females are shown to have more connections with the cerebral cortex like boys and they seemingly are still able to show emotional connections just as easily as when they typically have more amygdala activity for such tasks Because certain areas of the brain are activated with specific tasks we cannot assume that these brain activities can be directly implied to have connections with psychological processing and behaviors The fMRI showed that the amygdala and hypothalamus are more strongly activated in men than in women when viewing identical sexual stimuli Although there are differences in the areas that are activated in the amygdala between men and women we cannot conclude that these findings correlate to behavioral and emotional differences Men and women amygdala s are wired different and connect to different areas of the brain Men s are larger Androgen Insensitivity Syndrome Condition in which individuals are considered male because they have one X and one Y chromosome The body is unable to respond to the male hormone androgen causing the individuals body to have mostly female sex characteristics Complete AIS the body is unable to use any androgens and appear to be female and are typically raised female However these individuals do not have the female internal sex organs so they do not have a menstrual cycle and are unable to have children Partial AIS the body responds to some androgens so the individuals can have both female and male characteristics and be raised as either gender Both complete and partial occur just as often Genetic syndrome that runs in families Typically infertile but not always Lack of underarm hair pubic hair lack of acne during puberty and no menstruation in women Higher risk of testicular cancer Complete Androgen Insensitivity Syndrome CAIS refers to typical female external genitalia o Treatment may include either removal of the testicles after puberty when feminization is complete or prepubertal gonadectomy accompanied by estrogen replacement therapy Partial Androgen Insensitivity Syndrome PAIS refers to predominantly female predominantly male or ambiguous external genitalia o May need specific surgical procedures after puberty depending on the sexual preference assigned by the parents Mild Androgen Insensitivity Syndrome MAIS refers to typical male external genitalia Surgery should done within first 15 months of life Congenital Adrenal Hyperplasia CAH Group of inherited genetic disorders of the adrenal glands Effects of CAH are caused by a multistage process that begins with the failure to produce one enzyme and results in the overproduction of androgens It is the overproduction of androgens that CAH is most known for as it causes physical changes to both male and female genitals however this is only one effect of CAH Symptoms Ambiguous genitalia in girls Enlarged penis in boys Enlarged clitoris in girls Poor weight gain Weight loss Dehydration Vomiting Abnormal heart rhythm Very early puberty Early appearance of pubic or armpit hair in boys Rapid growth during childhood but shorter than average final height Irregular menstrual cycles in women Infertility in women and men Treatments surgery steroids medications Prenatal tests o Aminocentesis withdrawing amniotic fluid from the womb to test if the condition if present o Chorionis Villus Sampling Withdrawing cells from the placenta for laboratory analysis When a fetus is exposed to unusually high levels of testosterone it can alter their genetic state Girls with CAH prefer boyish activities and toys over the girlish ones CAH is an inherited disorder so there are no preventative measures Corpus Callosum the brain A thick band of nerve fibers