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

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?

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

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.

Reflective

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

Bell Ringer

• The scent of attraction

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? 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