Hormones
Using one or more examples,
explain functions of two hormones
in human behavior
Hormones
Chemical messengers
secreted by glands.
These glands are part of a
system called the
endocrine system.
Cortisol and Memory
• Cortisol is a hormone
produced by the
adrenal glands in
response to stress and
to restore homeostasis.
• Chronic stress may
result in prolonged
cortisol secretion…
• Which can damage the
immune system and
impair memory.
Newcomer et al (1999)
Experiment on Cortisol and Memory
Aim: To investigate how
levels of cortisol levels
interfere with verbal
declarative memory.
Newcomer et al (1999)
Experiment on Cortisol and Memory
Procedure: A self selected
sample (through and
advertisement) of 51
normal and healthy
people ages 18-30 was
used.
• Randomized, controlled
and double-blind.
• Three conditions….
Newcomer et al (1999)
Experiment on Cortisol and Memory
• Condition 1: High level
of cortisol (160 mg
tablet), was given.
Same as cortisol
released in a stressful
event.
• Condition 2: Low level
of cortisol (40mg
tablet). Same as minor
stressful event.
• Condition 3: A placebo
Newcomer et al (1999)
Experiment on Cortisol and Memory
Results:
• The high level group
performed worse on
verbal memory test
than the low level group
and placebo group.
• The low level group
showed no memory
decrease.
Newcomer et al (1999)
Experiment on Cortisol and Memory
Evaluation
• It was controlled and
randomized so it was
possible to establish a
cause and effect
relationship.
• They received informed
consent.
• Negative effect of cortisol
levels was reversible so
no harm was done.
Oxytocin and trust
• Oxytocin is secreted by the
hypothalamus into the brain
and into the bloodstream via
the pituitary gland.
• Linked to increase in trust.
• Evolutionary psychologist say
trust was critical in forming
relationships or staying away
from bad ones.
• Learning to trust in vital for
survival.
• One way it could work is by
reducing fear reactions via the
amygdala as a consequence of
betrayal.
Baumgartner et all (2008)
The role of oxytocin in trust in economic behavior.
• Aim: To investigate the role of oxytocin after breaches
of trust in the trust game.
• Procedure: The participants played a trust game used
by scientists to study social interaction.
Baumgartner et all (2008)
The role of oxytocin in trust in economic behavior.
Procedure:
• “Investor” player 1 gets a
sum of money and must
decide whether to keep it
or share it with a “trustee”
(player 2).
• What is shared is tripled.
• Player 2 must decide if the
sum should be shared
(trust) or kept (violation of
trust).
Baumgartner et all (2008)
The role of oxytocin in trust in economic behavior.
Procedure
• fMRI scans were carried
out on all participants.
• They received either
oxytocin or placebo via a
nasal spray.
• Participants played
against different trustees
and were given feedback
when the trust was
broken by the
experimenter.
Baumgartner et all (2008)
The role of oxytocin in trust in economic behavior.
Results
• Participants in the
placebo group showed
less trust after feedback
of betrayal. They invested
less.
• Participants in the
oxytocin group continued
to invest at similar rates
after receiving feedback
of breech of trust.
Baumgartner et all (2008)
The role of oxytocin in trust in economic behavior.
• The fMRI scan showed
decreases in responses in
the amygdala and caudate
nucleus.
• Amygdala is a part of our
brain that is involved in
basic emotions and has
many receptors for
oxytocin.
• The caudate nucleus is
involved in learning and
memory and plays a role in
reward related responses
and trust.
Baumgartner et all (2008)
The role of oxytocin in trust in economic behavior.
Evaluation
• Oxytocin could explain why
people are able to restore trust
and forgiveness in long-term
relationships.
• fMRI gave us an idea about a
possible correlation but gave us
nothing definite about cause
and effect.
• Giving the oxytocin artificially
may not reflect a true
physiological process.
• Oxytocin is very complex and it
is too simplistic to call it the
:trust hormone”.