Hormones, Sex Behavior, and Gender Identity Insights

Hormones and Neurotranmistters involved in sex behavior

Dopamine and serotonin and Activity of MPOA for sexual motivation in both male and female (rats) 

Sex

biological characteristics that divide into male and female categories  

• Verbal ability 

• Visual-spatial ability 

• Math 

• Aggression

Data that supported the idea that gender is different in these factors 

• Effect size in gender differences is not big and not meaningful in real world sense  

• Accurate from perspective if you test in certain way, different way they may not be there  

Task specificity 

Differences decreasing over time → Experience 

Explain why gender differences in behavior and cognition described by Maccoby & Jacklin are no longer thought to be completely accurate 

Gender

Set of behaviors that society picks what is appropaiate for sex

Terminology for gender

• Gender role 

• Gender identity – subjective feeling of feeling male or female, how do you identify  

• Gender expression  

Critical Periods – prenatally and sometimes very early post-natally which lead to permanent changes

What are organizational effects? and examples?

Activational effects

• Later 

• Transient – if hormones are there the animal exhibits a type of behavior  

• At puberty activation of HPG axis 

• later in life, go through your life, hormone is there a behavior, if hormone is not there then you don't see a behavior 

evidence for sex differences in stress-related circuits and immune function

Males = no big change in corticosterone, over time in males 

Females = big change  

• Behavior in males = increase in depressive behavior when stress is actively happening AND No longer getting exposed, their behavior goes back to what it what before 

• Behavior in Females= increase in depressive behavior for first 28 days, increase in behavior stays elevated even when not exposed to the stress  

• Vasopressin = respect to thirst 

• Deleted cells in adult mice that encode for vasopressin, increases social investigation of females but also increases anxiety levels in male mice  

• Oxytocin = birth and milk letdown for nursing  

• Get a stress related release of oxytocin and dappen that stress response, in males resolves quickly (levels go down quickly) 

• In female's oxytocin is extended in time and last for a week or two, oxytocin levels stay higher in response to a stressor  

Examples of sex differences in social behaviors related to vasopressin and oxytocin

• Genitals and secondary structure develop at a different time than your brain  

• Brain developing exposed to different to hormonal environment  

 Explain why there might be a "mismatch" between genitalia and the brain for people with gender identity