perry et al

• to investigate how oxytocin affects preferred interpersonal distance for those scoring high or low in empathy traits
• • 54 male undergraduate students
  • from the university of Haifa, Israel
  • 19-32 year olds
  • received course credit/payment
• • laboratory experiment
  • self-report (questionnaire & computersied tasks)
  • independent measures design - randomly allocated

  DV: preferred interpersonal space (%) of remaining distance

  IV: empathy score (high or low), treatment/oxytocin or placebo (saline solution), condition (stanger, authority figure, friend, ball)
• calculating empathy scores

  • participants take the 'interpersonal reactivity index' test (IRI) and split into two groups based on the scores
  • high empathy = ≥40
  • low empathy = ≤33
  • 20 participants in each (14 participants scored between 33 and 40 - cant determine if they have high or low empathy)
• treatments

  • double-blind
  • participants took either oxytocin or salt water
  • self-administered 3 drops into each nostril
  • participants waited 45 minutes (for oxytocin to take effect) and completed the IRI during this time
• experiment 1 - CID task (conditions IV)

  • computerised task (96 trials)
  • shown name of an approaching figure (ball, friend, stranger or authority figure)
  • figure can appear at 1 of 8 entrances around the circle
  • the figure slowly moves towards the middle figure (participant) and participants can press the spacebar to stop the figure
  • calculate the % of space left or remaining distance (DV)
• experiment 2 - choosing rooms

  • computerised task (168 trials - 86 photo pairs x2)
  • told to pick a room to 'have a conversation with another participant' (doesn't happen)
  • shown animated room pictures with 2 identical chairs, table, plant, closet, lamp and clock (rooms were very similar)
  • each pair, distance between chairs varies 20-140cm apart and angles of chairs varies from 0°, 45°, 90°
  • participant picks the room they would prefer each time
  • DV - mean average preferred chair distance (cm) and mean average preferred chair angle (°)
  • (same IVs but conditions are: chair position vs table position)
• experiment one results:

  high empathy group

  • oxytocin (23.3) decreased preferred mean distance from the figure compared to placebo (26.1)

  low empathy group

  • oxytocin (30.2) increased preferred mean distance from the figure compared to placebo (26.9)

  experiment two results:

  high empathy group

  • oxytocin (78.1) caused closer chair distances compared to placebo (80.5)

  low empathy group

  • oxytocin (80.1) caused greater chair distances compared to placebo (78.3)

  oxytocin did not affect preferred chair angle
• • oxytocin had an impact on interpersonal distances preferences, depending on individual empathy level
  • oxytocin may only increase closeness in highly empathetic people
• strengths

  • standardised procedure - CID task timings and figures, same room photos, nasal spray and waiting 45 minutes - high reliability and replicability, consistency
  • high level of control - lab experiment, double blind procedure for nasal spray (avoid researcher bias and demand characteristics), same setting and number of computerised trails - increases internal validity
  • quantitative data - numerical results (%) for itnerpersonal and chair distances comparing placebo and oxytocin conditions - easy to analyse statistically and compare IV levels
• weakness

  • unrepresentative sample - only males used from Israel, 19-32 year olds - ungeneralisable to women or people from different countries (they may prefer closer interpersonal differences)
  • low ecological validity - artificial setting and computerised tasks (imaginary figures approaching) - low mundane realism, low generalisability (not experience the same discomfort or emotional factors as personal space is affected in real life)
• + informed consent gained

  + right to withdraw

  + protection from harm (press spacebar to reduce distress)

  • deceived about having a meeting in experiment two
  • intrusions into personal space may have caused distress (even when animated)
  • deception about treatments? - double blind
• • applications to everyday life: used to help people with social problems (eg. autistic people), administer oxytoic to help them feel more empathy
  • nature-nurture: environment affected interpersonal distance; people have different empathy levels
  • individual-situational: oxytocin changed behaviour; individual empathy level affected interpersonal distance
• 1. interpersonal distance: the distance between two people
  2. personal space: an area with invisible boundaries, surrounding a person's body, which intruders may not cross
  3. empathy: a person's ability to understand the thoughts, feelings and experiences of another
  4. social hormones: hormones involved in social behaviour