Steven Crane Compiled Section Handouts. Human Behavioral Biology 2012

Spotted hyenas.

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  Females have more androgens, have clitorises like penises, fat pads like scrotums.
  

Their social system has females on top. They also give birth to only 2 cubs. What do you predict for their feeding order?

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  Now cubs go first, then females, then males.
  
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  Opposite of how it is in lions.
  

How do we explain PMS?

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  Some hypotheses about it being a myth, invented by the west, a "dependent" personality style, a conflict between being productive and reproductive etc.
  
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  Bleh to all that. Baboons have the same profile of irritability/aggression so it's probably biological. AND males
  

have the same mood shifts along with female partners' periods so it can't just be the hormones.

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  So it's biology within a social context.
  
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  It might also be about depression. How could you explain that with hormones?
  
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    Drop in progesterone near the end of the cycle.
    
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    Progesterone potentiates GABA, as you should recall.
    
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    Opioid levels also drop around the period.
    

Long-term environmental effects on aggression

How does Lorenz' hydraulic model of aggression hold up to scrutiny?

• It would say aggression is inevitable, and should be less likely after previous aggression.

• But aggression is NOT inevitable. And aggression tends to beget more aggression.

How about the frustration-aggression Marxist hypothesis?

• Holds up well. A lot like displacement theories.

• Exception: aggression goes down during periods of famine, of scarcity. This would argue that aggression is more behavioral fat.

How about behaviorist accounts of aggression?

• This would predict it's all about reinforcers: rewards and punishments. That will determine aggression.

• Sort of true: premeditated crimes are influenced by penalties. But crimes of passion are not.

Human infants develop ego boundaries, theory of mind, self/other distinctions.

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  These as precursors for empathy and pro-social behavior.
  
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  Necessary but not sufficient, as seen with sociopaths who have great theory of mind
  

Does violent TV make kids more aggressive?

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  Same story that comes up over and over: it exacerbates pre-existing tendencies. Makes unaggressive individuals less aggressive. Makes aggressive individuals more aggressive.
  

How do you respond to the claim that violence is biologically predetermined, since aggressive violence peaks in adolescent males?

• You'd bring up the data comparing murder rates in Chicago/Toronto/London.

• They all follow the same rates of violence curves.

• But the absolute amount of violence is hugely culturally determined.


Take-Home Point: your long-term environment teaches you the social contexts that are appropriate for violence.

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  Huge predictor of violence: living in a culture that rationalizes violence