Olfactory cues can influence judgments of facial attractiveness. In a study, female participants rated the attractiveness of male faces presented briefly along with different odors. Faces were rated as less attractive when presented with unpleasant odors compared to pleasant or neutral odors. The presence of olfactory cues, even unrelated body odors, can have a small but significant cross-modal effect on evaluations of non-olfactory stimuli like facial attractiveness. However, the effects may also be due to distraction or halo dumping rather than true perception changes.

1. Olfactory Cues Modulate
Facial Attractiveness
Demattè, Österbauer, & Spence
2007

2. 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.

3. 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.

4. 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

5. Background
• Woman’s preference for the scent of some males
has been shown to change with her menstrual
cycle
• Smelly Boys…..

6. AIM
• To investigate whether olfactory cues can
influence people’s judgments of facial
attractiveness

7. HYPOTHESIS
• A pleasant versus unpleasant odor can
modulate female participants’ ratings of
the perceived attractiveness of briefly
presented male faces

8. 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

9. 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

10. 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

11. Bell Ringer
• The Human Face
• How much of beauty do you think is
socially constructed? In other words, how
much of beauty is what we are told is
beautiful?

12. 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)

13. 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

14. 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

15. 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

16. Labeled
Magnitude
Scale

17. 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.

18. Reflective
• Read the following article What Influence
Does Smell Have on Attractiveness?

19. Bell Ringer
• The scent of attraction

20. 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.

21. 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

22. • 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

23. Strengths/Weaknesses
• Strengths
– Controlled
– Counterbalanced to control for order effects
– Replicable
• Weaknesses
– Generalization (population/sample)
– Demand characteristics
– Halo dumping
– Validity (ecological, construct)

24. Evaluation
• Construct validity? 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)

25. 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

26. 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

27. 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