Human Morality

1
Human Morality

• NoH 2006

2
What is morality?

• Alexander (1985) Moral system is a society with
  rulesrules are agreement about what is permitted
  and what is not, about what rewards and
  punishments are likely for specific acts, about
  what is wrong and what is right
• Morality reinforced by the society-
  cross-cultural differences?

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• Planalp (1999) to behave morally is to judge
  right and wrong, good and bad, and to behave
  accordingly
• morality comes from within- are there moral
  universals?

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The biology of morality

• Hormones and social behaviour
• Oxytocin and trust
• Testosterone, aggression and empathy
• Brain structures and morality
• PFC
• OFC
• Genetics and Morality

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HormonesOxytocin

• Regulates positive social interactions in mammals
  (pair bonding, maternal care, sexual behaviour,
  social attachments)
• In humans, oxytocin increases trust and
  cooperation in strangers (Kosfeld et al 2005, )

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Hormones testosterone

• T is related to aggressive behaviour and
  competition in mammals
• T in humans related to reduced empathy, criminal
  violence and delinquency (e.g. Dabbs and Morris
  1990, Hermans et al 2006)
• T enhance competitive abilities, reduce empathy

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Phineas Gage

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The prefrontal cortex

• PFC central executive, morality, empathy,
  impulsivity, emotional control etc
• Orbitofrontal Cortex (OFC) activates emotions
  necessary for decision making
• OFC lesions can lead to acquired psychopathy
  (see Kiehl 2006)

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The Anterior Cingulate Cortex

• Caudal region of ACC activated in conflict- ACC
  activation in normal people when defecting, but
  no such thing in psychopaths (Rilling et al
  2006).
• Rostral ACC affect regulation, impaired in
  psychopaths

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Psychopathy- frequency dependent selection??

• Emotions control our behaviour
• Primary psychopaths- 2 of population
• Some genetic influence (e.g. Larsson et al 2006)
• Do well when rare
• Have evolved as a successful cheater strategy?

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How can we explain morality?(Lahti and
Weinstein, 2005Alexander, 1989)

• During human evolution, there was competition
  both between and within social groups
• Moral behaviour is facultative, and evolved both
  for inter and intra-group purposes
• People adhere to moral rules when there is an
  external threat to the group
• Relaxation of morality more likely when the
  social group is stable
• Both group selection and selfish genes
  explanations!

12
Taking Stock

• Altruism is a complex phenomenon, one explanation
  is unlikely to account for all altruistic actions
• In the EEA, humans evolved in small kin-based
  groups. It is possible that the evolved
  psychological adaptations for altruism reflect
  this.
• Kin selection and reciprocity alone are not
  sufficient explanations for altruism in humans
• The role of proximate causes (e.g emotions) are
  also important.