Povinelli TOM chimpanzee studies

Chapter 15: Santos, L. R., Flombaum, J. I., & Phillips, W. The evolution of
human mind-reading: How nonhuman primates can inform social cognitive
neuroscience (pp. 433-456)
• The secret to our evolutionary success is our
social intelligence and the key to our social
intelligence is TOM; the ability to infer the
motivations, intentions, and belief states of
others. “Why is so-and-so doing x?”
Neuroscience of TOM
Diverse areas of brain have been
implicated in variety of studies including:
Visual cortex
Anterior cingulate cortex
Medial frontal cortex
Superior temporal sulcus
Major limitation of neuroscience studies
is inability to break down TOM in to
elementary components and identify
which parts of brain are associated with
specific components of TOM
For example: visual cortex probably
involved in identifying self-directed action
and amygdale probably involved in
identifying emotional signals, but isolating
this is difficult
Do nonhuman primates have TOM?
• Dan Povinelli: No
• Brain Hare: Yes, sometimes
Povinelli TOM chimpanzee studies
Hare et al.’s set up
Rhesus Macaques and TOM
• Cayo Santiago field station in Puerto Rico.
• Human experimenter approach monkey; placed a platform on the
ground and put a grape on the platform. E then either faced grape or
(a) turned around; (b) averted eyes; (c) blocked vision with small
barrier or blocked mouth with small barrier.
Rhesus TOM
• Would monkeys take into account what a competitor knows based
on past experience, rather than what a competitor currently sees?
• E placed to grapes on platform where one could be triggered to roll
to a different location. E would be “unaware” (from monkey’s
perspective) of new location of rolled grape. Monkey watches.
Monkeys attempt to steal grape that E did not know had moved.
Behavioral- abstraction hypothesis.
Alternative interpretation offered by Povinelli: Behavioral- abstraction hypothesis.
Certain bodily postures are more likely to be associated with non-aggressive
behaviors. Monkey or chimpanzee notes bodily position of competitor and notes
likelihood of being challenged by competitor.
“Competitor does not know where grape is” or “competitor is not in a position to
challenge me for grape”
Problem is that these two hypothesis may be indistinguishable in terms of predicting
Behavioral- abstraction hypothesis
• Authors argue that TOM interpretation probably wins on
grounds of parsimony
• BA hypo argues that monkeys and apes use correlated
behavioral cues to predict future behavior,
• But why are only cues directly associated with mental
states used? Direction of mouth or nose are ignore but
equally correlated to behavior.
• If we are only using behavioral cues that constrain
mental states then aren’t we really down to a TOM
Neuroscience evidence: Superior Temporal Sulcus
• In monkeys: important for
registering another’s head
and body position and
possibly what another “sees.”
• In humans: important for
interpreting goals and
• This system may be
malfunctioning in autistics
who have difficulty using
gaze direction as an indicator
of another’s goal or desire.
STS and Amygdala
• Amygdala may play the role of binding emotional content
to another’s goal based on gaze direction. Link may
occur for nonhuman primates in competitive situations
but not cooperative. Could this be important evolutionary
distinction between human and nonhuman primates?

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