Gender and the Brain

Kind Essentialism (based on neuroscience)

• Kind Essentialism (based on neuroscience) says: to be male is essentially to be an individual with a male brain; to be female is essentially to be an individual with a female brain.

• Is this plausible? Are there male and female brains?

 Patricia Churchland

• She is a philosopher and neuroscientist

• Churchland argues that male and female brains do differ

• An XY fetus (chromosomally male) develops testes in the second month; testes produce testosterone and other hormones. Testosterone and the other hormones "masculinize" the brain

• An XX fetus (chromosomally female) develops the "default" brain that isn't masculinized by testosterone

• Below, data on testosterone levels throughout life (from this article). 

The top graph shows males from conception through puberty.
The bottom graphs show rats, mice, and humans in the hours after after birth
(top line male, bottom line female).

• What difference does a "masculinized" brain make? It depends on the species.

• In birds, only males sing and engage in courting displays. Females choose among the males.

• In elephant seals, only the males fight each other. Females choose among the males.
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• In humans, XY individuals (with male brains) are more aggressive on average

• Suppose all this is true. Then is Kind Essentialism true? (To be male is essentially to be an individual with a male brain; to be female is essentially to be an individual with a female brain.)

• Two ways for individuals to differ

• Sexual dimorphism. All the males take one form, all the females take another (e.g. male and female deer).

• Different averages.  Like in the case of human heights. 

• If brains of men and women just differ like height, then we can't define being female as having a certain kind of brain.  

• Is Churchland talking about sexual dimorphism or different averages? (p. 125-136)

Cordelia Fine 

• She is a psychologist and journalist who also writes about philosophy

• Fine doubts that testosterone shapes the human brain/mind significantly.

• Evidence from rats and birds is inconclusive for humans

• Humans have higher cognition and culture

• Need to detect behavioral differences in babies before people start treating boys and girls differently.

A Famous Study

• Gender differences on Day 1, according to Jennifer Connelan (2000 study).



Newborns could look up at face or mobile.








More males had mobile preference, more females had face preference



• Fine's objection (in chapter of book we didn't read): Connelan knew which were boys and which were girls

• Fine's view: science hasn't proven that testosterone creates different male and female brains (even on average)