Olfactory Cues Modulate Facial Attractiveness
Demattè, Österbauer, & Spence 2007
Bell Ringer
• Which of your senses do you use to acknowledge the attractiveness of a person?
• List and explain how you use each of the senses you listed.
Background
• Facial Attractiveness according to our sense of vision has to do with facial symmetry
• How much the average face conforms to the average prototype.
Background
• Attractiveness is not just dependent on the vision but is often adjusted by other sensory cues – Voices have been shown to influence a person’s
perceived attractiveness
• Olfactory cues (smell) also play an important role in nonverbal communication – A significant positive correlation found between the
rated sexiness of a man’s body odor & his facial attractiveness to females
Background
• Woman’s preference for the scent of some males has been shown to change with her menstrual cycle
• Smelly Boys…..
AIM
• To investigate whether olfactory cues can influence people’s judgments of facial attractiveness
HYPOTHESIS
• A pleasant versus unpleasant odor can modulate female participants’ ratings of the perceived attractiveness of briefly presented male faces
Method/Procedure
• 16 female volunteers
– The University of Oxford
– Age 20 to 34, M=24
– Completed a questionnaire ensure that they had a normal sense of smell, no history of olfactory dysfunction, & normal vision
• Chose women because previous research has suggested that females may be more sensitive to the effects of olfactory cues than are males
Method/Procedure
• Forty male faces for visual stimuli – From a standardized database
– Extensively characterized for attractiveness & categorized into high, medium, & low attractiveness
– 20 faces from each of the high & low groups
• Four odors (2 male & 2 non-male) & clean air – 2 pleasant odors: geranium & male cologne ‘‘Gravity”
– 2 unpleasant odors: male body odor & rubber
• A custom-built computer-controlled olfactometer was used to deliver the odorants
Method/Procedure
• Laboratory experiment
– Repeated measures design
• IV= Pleasant odors, unpleasant odors, neutral odors
• DV=Modulation of female participants’ ratings of the perceived attractiveness of male faces
Method/Procedure
• 3 blocks of 40 random trials (each person completed 120 trials)
– Each face was randomly presented 3 times during each session
• Once with a pleasant odor
• Once with an unpleasant odor
• Once with a neutral odor (i.e., clean air)
Method/Procedure
• Participant sat staring at a computer with their chins on a chin rest
• They were told to look at a fixation mark on the screen
• They were to exhale through their nostrils when they heard a quiet tone and inhale when they heard a louder tone and which point an odor was released
• They had to indicate if an odor had been released or not using the keyboard
• 1 second later one of the faces appeared for ½ second in the center of the screen
• As soon as the face disappeared the odor stopped and clean air was delivered.
• The screen then turned black
Method/Procedure
• Then a 9-point rating scale appeared and the participants were to rate the perceived attractiveness of the face that they had just seen
• 1 (least attractive) to 9 (most attractive)
– What is this called?
• As soon as they made their rating, clean air was delivered and the next trial started
Bell Ringer
• The scent of attraction
• Philosophical Chairs!!
• Beauty is socially constructed. In other words, the idea of beauty is what we are told is beautiful?
Method/Procedure
• At the end each participant was asked to smell the odors individually & to rate each odor on several different dimensions use a pen and paper Labeled Magnitude Scale (LMS) from 0-100. – odor intensity – odor pleasantness – odor familiarity
• The order of presentation of the odors and the scales was randomized between participants
Labeled Magnitude Scale
Method/Procedure
• In order to counterbalance the presentation of each face/odor combination, the entire set of 40 faces was divided into 4 groups of 10 faces each (5 high attractiveness & 5 low attractiveness) with close to the same mean attractiveness. – Each group of faces was then presented with 1
different possible combination of pleasant–unpleasant odors, counterbalanced across participants.
Method/Procedure
• So each participant rated
1. 10 faces presented with clean air, the geranium odor, & the body odor during the experiment.
2. 10 faces with clean air, the male perfume, & the rubber odor
3. 10 faces with clean air, geranium odor, & the rubber odor
4. 10 faces clean air, the male perfume, & the body odor.
• The same odor was never presented to participants on consecutive trials.
• The experiment lasted for approximately 50 min in total.
Results/Findings
• The faces were found significantly less attractive when presented together with an unpleasant odor than when presented with either a pleasant odor or with the neutral clean air
– Didn’t matter if the odor was body relevant
• There was no significant difference between pleasant versus neutral clean air
• Adds to a growing list of studies demonstrating that the presence of olfactory cues can exert a small but significant cross-modal influence on people’s judgments of a variety of non-olfactory stimulus attributes/qualities (Smell matters)
– Adds to previous evidence that shows that the presence of fragrance cues can influence people’s evaluation of job applicants
– Would be interesting to see what happens under more ecologically valid conditions
Strengths/Weaknesses
• Strengths – Controlled
– Counterbalanced to control for order effects
– Replicable
• Weaknesses – Generalization (population/sample)
– Demand characteristics
– Halo dumping
– Validity (ecological, construct)
Evaluation
• Construct validity- refers to the validity of inferences that observations or measurement tools actually represent or measure the construct being investigated? Yes – A link could be established between the face & the smell
because the technique used presented them as a single stimulus & cross-modal (perceptions involving 2 senses) interactions were checked
– Presentations of the odors were brief so the influence of the odors on mood didn’t interfere with face preferences
– Trials were randomized so the effects could be attributed to the smells, not order effects (practice or fatigue)
Evaluation
• Construct validity? No
– The unpleasant smells may have distracted the participants’ attention causing them to find the faces less attractive rather than affecting perception of the face
– The participants might have been halo dumping
Evaluation
• Were the effects due to a halo-dumping? – Can occur whenever the appropriate response
alternative for a relevant attribute is unavailable to participants. This can lead participants to ‘dump’ the values for a relevant attribute that is not available in the range of alternative response scales provided • So they describe a smell as sweet when it is really
vanilla • In this case they might have been expressing their
like or dislike of the odor on the attractiveness scale – Possible as they only had one scale to use, so couldn’t
separate their evaluations
Evaluation
• Demattè et al say no – the participants in the study had to perform
an odor detection task at the beginning of each trial, meaning that odor and visual information were responded to as 2 distinct and individuated
– ‘‘Attractiveness’’ is a clear, natural, & easy characteristic to consider when rating human faces, so it is unlikely that the participants had doubts concerning which variable they were supposed to rate in the task