Hormones
Sample question: Explain the
function of two hormones in human
behaviour.
Adrenaline
• Behaviour – “Fight or flight” responses –
preparing body to deal with threats.
• May be responsible for the creation of
emotion
Examples
• Associated with fear but also excitement and positive
feeling.
• Increased alertness
• Increased the flow of oxygen and blood to the brain
• Increased heart activity- heart rate, blood pressure
• Dilates blood vessels, eye pupils
• Moves glucose and oxygen away from internal organs
to the extremities
• Released from the adrenal medulla of the adrenal
glands
Melatonin
• Behaviour – regulates the sleep cycle and
related behaviours
• Secreted from the pineal gland – has the
ability to sense light
• secreted during darkness but not light
Example
• Melatonin also affects activity of the pituitary gland and
wakefulness – “turns off the body”
• SAD – Seasonal Affective Disorder – depression linked to the
beginning and the end of winter.
• Avery et al. 2005 – rated the depression in 95 subjects grouped by
various degrees of light exposure. Found that symptoms were
related to shifts in subjects sleep patterns resulting from dawn
simulation, bright light therapy, or dim red light exposure.
• Lewy et al 2006 – found that the duration of melatonin exposure
triggered activities in the brain. SAD may result from biological
instincts becoming incompatible with lifestyle demands.
• Jet-lag is a result of changes in melatonin cycles – dose of
melatonin can alleviate jet lag
Oxytocin
• Behaviour - The “love hormone” or “trust
hormone”
Example
• Released during birth and physical stimulation during breast
feeding.
• Involved in formation of social bonds – rats injected with
oxytocin would switch from grooming themselves to
grooming their pups.
• Also involved in stress reduction – positive physical contact
between husband and wife resulted in lower blood pressure
Example contd.
• Morhenn et al. 2008 – grouped 96 volunteers
into three groups by massage, rest, and trust
exercises. They found that people who received
massages showed no rise in oxytocin levels but
would be more generous and trustworthy with
money sacrifices. Donations were more likely to
be reciprocated after a massage and when a
donation was returned in the experiment, a rise
in oxytocin was detected. Therefore oxytocin is
related to increased generosity and co-operation
Schachter and Singer, 1962
Adrenaline and emotion
• Aims – to test the effect of context on the cognitive evaluation of
emotion during the release of adrenaline in subjects
• Method – 184 male participant volunteers, three experimental
groups and one control group. All informed they were getting
vitamin injections while three groups got adrenaline injections
and one final group received a saline placebo. Three
experimental groups were informed of three different anticipated
side effects. Two emotional contexts were added by
confederates, one of euphoria (playing office games) and the
other of anger (personal questions in a questionnaire)
• Structured observations followed along with self-reports of
emotional mood for each subject when their context exposure
was complete.
Schachter and Singer 1962 contd.
• Findings - Subjects who received incorrect side effect
information in the euphoric context showed corresponding
euphoric behaviours and reported more happiness
• Subjects who received incorrect side effect information in
the angry context did not report corresponding angry
feelings but subjects in this context who received correct
side effect information performed less angry behaviours
than those who received incorrect side effect information.
• Therefore, emotion occurs as a result of cognitive labelling
in which the physiological cues are combined with
contextual cues to create the subjective experience of
emotion.
Variables and validity
• Independent variable – the contextual cues of anger and
euphoria, the anticipated side effects of each group, the
differences between subjects in the experimental group
and the control group.
• Dependant variable - behaviour displayed during the
context experiences as well as the self-reports of emotional
states of the participants.
• Validity – Some unanticipated data – shouldn’t anger
groups have shown angry behaviours? Shouldn’t anger
groups have reported angry emotions?
• Possible susceptibility to demand characteristics – was the
experiment double blind or single blind?
• Others??????