Table 1: Overview of the experimental procedures and dependent variables of the 2 studies.

Procedures and variablesStudy 1 
Degree of sociality
( )
Study 2 
Degree of sociality and properties of the social relationship
( )

DesignBetween-subject designWithin-subject design
Social manipulation(i) Moderate sociality (nonvisual interaction)
(ii) High sociality (visual interaction possible)
(i) No sociality (alone)
(ii) High sociality—formal (with the experimenter)
(iii) High sociality—intimate (with the partner)
Pain inductionPhasic heat stimuli
(painful and nonpainful)
Phasic heat stimuli
(painful and nonpainful)
Assessment of smilingAU 12
(frequency and intensity being coded)
AU 12
(frequency and intensity being coded)
Self-report ratingVAS (0–100)VAS (0–100; with 50 being labelled as slightly painful)