Dematte et al.

Aim of study:
experiment to investigate whether olfactory cues affect facial attractiveness

Method of study:
Natural experiment

Participants
-16 females from University of Oxford
-mean age 26 years old
-naive to the purpose of experiment
-completed confidential questionnaire to ensure they have a normal sense of smell/ eyesight
-sample questions asked:
1. do you suffer from asthma or any other born allergies?
2. are you currently suffering from a flu?

why use females only?
1. previous research shows females more sensitive to the effects of olfactory cues
2. females might rely more on olfactory cues in mating behaviour

Apparatus:
1. 40 male faces
2. 4 odours and clean air
3. Olfactormeter

Apparatus 1: 40 male faces`
– used as visual stimuli
– have been extensively characterised for attractiveness
– categorized into different attractive groups

Apparatus 2: odours and clean air
Pleasant:
-male fragrance ‘gravity’
-geranium

Unpleasant:
-rubber
-synthetic body odour

Apparatus 3: olfactormeter
-custom built, computer controlled
-used to deliver the odours
-odours diluted in diethyl phthalate

Design of study:
-repeated measures
-3 blocks
-1 block: 40 faces (5 attractive 5 less attractive)
-1 face = 1 trial
-120 trials in total (40faces x 3 blocks)
-each face randomly presented 3 times , one with neutral odour, one with unpleasant odour, one with pleasant odour
-same odour was never presented on consecutive trials
-experiment lasted for 50 minutes

Procedure
1. quiet tone
2. exhale
3. louder tone
4. inhale
5. odour delivered
6. fixation cross disappears
7. male face appears
8. face & odour disappears
9. clean air presented
10. screen turns black
11. 9 point rating scale on screen
12. rate
13. fixation cross appears

Procedure*
-participants sat on chair 70cm away from computer screen
-chin rested on chin rest
-clean medical air was delivered continuously through the olfactormeter except during delivery of odour
– after every 40 trials=rest 5 minutes

Post experiment task
-each participant asked to smell odours individually
-rate odour using different dimensions:
1. odour intensity
2. odour pleasantness
3. odour familiarity

Results:
-faces less attractive when presented with unpleasant odour (didnt matter if the odour was body relevant)
-no significant difference between pleasant versus neutral/clean air

Strengths:
-controls
-counterbalancing to control for order effects
-replicable

Weaknesses:
-generalization
-demand characteristics
-ecological validity
-construct validity

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 odours were brief so the influence of the odours 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)

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