Dematte et al.

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

Method of study:
Natural experiment

-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

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
-male fragrance ‘gravity’

-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

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

-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

-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

-counterbalancing to control for order effects

-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