Olfactory Cues Modulate Facial Attractiveness

Dematte, Osterbauer, & Spence (2007)

BackgroundFacial attractiveness has been shown to be a universal

socially important cue and an important factor in our overall rating of physical attractiveness

One’s appearance has also been shown to be impacted by other sensory cues, such as one’s voice and smell

Past studies have shown that we tend to rate those with direct or indirect pleasant scents higher than those without scents

Smell is the most primitive and provocative We categorize it from appealing to repulsive (rarely neutral)

Scents evoke emotional memories

Background

Past research has shown:Women look best at times of ovulation (yes, this was an actual study-

stripper study- http://www.unm.edu/~gfmiller/cycle_effects_on_tips.pdf)

Women think men look best when they are ovulating Brynar (2008) study found evidence that women who take birth

control pills have a tendency to interfere with one’s fondness of a mate with different genes and instead attracts them to potential mates with more similar genes

Voices have been shown to influence a person’s perceived attractiveness

(English accent recently ranked #1)

BackgroundPrevious research did not vary olfactory cues (which Dematte

does here)Numerous studies confer that women have a better sense of

smell than men (sharpest at ages 20-40)Current study only presented male faces to female Ps because: -previous studies suggest that females are more sensitive to olfactory cues -suggested that females might rely more on olfactory cues

for mating behaviors than males

Aim & Hypothesis of the StudyAim: To investigate whether the perceived

attractiveness of faces is affected by olfactory cuesIn particular, the study investigated whether a pleasant

or unpleasant smell affects one’s judgments of facial attractiveness

Hypothesis: A pleasant odour will result in a higher rating of the perceived attractiveness of the presented male faces

Methodology- SampleNo indication of sampling methodology16 females from the University of OxfordAge range 20-34, mean age of 26All were naïve as to the purpose of the experiment All answered a questionnaire for control purposes:

Good general health & no colds/flu, and/or allergiesNormal sense of olfactory and visual sensesAbility to perceive odours and colors

Methodology- VariablesIV- variations of odour

(pleasant [cologne/geranium], unpleasant [body odour/rubber], or neutral [clean medical air])

IV- Attractiveness of the image (high or low)DV- rating of perceived attractiveness of male

faces (1-9 scale with 1 lowest and 9 highest)

Methodology- Apparatuses40 male faces chosen from work by Perrett (1998)

http://www.perceptionlab.com/WEBPAGE/Research/Research.html 20 faces rated as “high” and 20 rated as “low” facial attractiveness

4 odours used in the study (from pilot research): Pleasant odours: Gravity cologne & geranium Unpleasant odours: rubber & synthetic body odour 2M3M Neutral odour of ‘clean medical air’ also used to clear out the testing

roomCustom-built olfactometer to deliver the odourants

Flow was modulated through a regulator at adjusted concentrations to standardize procedure

Methodology- DesignLab studyRepeated measures design with counterbalancing

The odours (including neutral) and the faces were presented multiple, specific times to eliminate demand characteristics

Overall experimental session consisted of 3 blocks of 40 randomized trials (3 sets × 40 faces = 120 total)

Each face was randomly presented 3 times during each experimental session (once with pleasant, once with unpleasant, & once with neutral)Each time, the Ps rated the face

Methodology- DesignTo counterbalance the presentation of each face/odour

combination, the 40 faces were divided into sub-groups of 10 each- 5 high and 5 low attractiveness per group Resulted in 4 sets of pictures (40 total per set) that were seen with each

face 3 times, resulting in 120 trials total from the combined 3 experimental sessions (each session also counterbalanced)

Each face was presented with one different pleasant odour, an unpleasant odour, and the clean medical air

The same odour was never presented on consecutive trials A 5-minute break was given between each session

Experiment lasted about 50 minutes total

Example block of trials breakdown Set 1 Set 2 Set 3 Set 4

10 faces (5↑, 5↓) (each shown 3×)

10 faces(5↑, 5↓) (each shown 3×)

10 faces(5↑, 5↓) (each shown 3×)

10 faces(5↑, 5↓) (each shown 3×)

Clean airGeraniumBody odour

Clean airCologneRubber

Clean airGeraniumRubber

Clean airCologneBody odour

Methodology- Procedure1. Participants sat 27 ½ inches from computer screen utilizing a chin rest to view the 5×7 image & look at the ‘X’ focal point

When they heard the ‘quiet tone,’ Ps start exhaling via nose and when they heard the ‘loud tone,’ Ps start inhaling via nose

2. The odour was delivered (P confirmed the scent by pushing a button on the keyboard) and the face appears for a ½ second3. Screen goes black & clean air pumped in again4. A 9-point scale was then presented on the screen for the Ps to rate the facial attractiveness of the pic

1 least attractive, 5 neutral, 9 most attractive5. After rating selection, process repeated

Presentation of odour sequence

Methodology- Procedure Clean medical air was presented throughout the trials except

when the odourant was deliveredPs given a 5 minute break after each trial to limit fatigue and/or

olfactory adaptationAt end of the experiment, Ps were asked to smell the odours

individually and rate each on intensity, pleasantness, & familiarity from 0-100 on Labeled Magnitude Scale (LMS)

Presentation of odours and scales were randomized among Ps

Labeled Magnitude Scale (LMS)

Results of the Study

Highest mean facial attractiveness- male fragrance 5.73Lowest mean facial attractiveness- body odor 3.64 Combined pleasant= 4.85, Combined unpleasant= 4.42, Neutral= 4.90

Results of the StudyThe rating of faces with odours revealed:

Results revealed a significant main effect of odour pleasantness on participants’ facial attractiveness rating Indicates that the odour (both pleasant an unpleasant) impacted the

rating of the face by the PsPs considered the faces as being significantly less attractive

when presented with an unpleasant odour compared to a pleasant odour or clean air

However, there was no significant difference b/w pleasant versus neutral air ratings

Results of the Study

The LMS data revealed:Odour intensity scores revealed that the pleasant and

unpleasant odours were perceived as more ‘intense’ than the clean air

Odour intensity scores revealed no significant difference b/w the intensity of the pleasant odour & the unpleasant odour

All three odour categories were judged to be equally familiar to the Ps

ConclusionFemales are more likely to judge a male face as being:

(a) Slightly more attractive when presented with a pleasant odour or neutral odour

(b) Slightly less attractive when presented with an unpleasant odour

There is no perceived difference in attractiveness between a face with a pleasant odour and a face with a neutral odour

Strengths and WeaknessesStrengths

‘Standardized’ questioning to reduce variables of PsControlled lab setting increases validity & is more replicablePresentation of faces counterbalanced to control for ordering

effects and demand characteristicsFaces used from the standardized databaseFew (if any) ethical concerns

WeaknessesDemand characteristics possibilitiesLow validity (ecological, construct) Low generalization (pop/sample size)Ethnocentric