Zero effect of crowding on arousal and performance: on 'proving' the null hypothesis

This study examined the effect of crowded versus uncrowded conditions upon pulse and self-rated arousal, and upon verbal production performance in subjects' first and second languages. Participants were 52 francophone college students. Arousal estimates were identical for crowded and noncrowded conditions as was verbal performance, thereby contradicting the theories of Zajonc (1965) and Freedman and Perlick (1979) in which crowding is viewed as an activating and intensifying stimulus. Crowding itself appears to have no direct effect on arousal or behaviour as measured.