Assimilation and contrast effects in suboptimal affective priming paradigm

SUBOPTIMAL AFFECTIVE PRIMING PARADIGM Contemporary psychology does not question the existence of psychological processes that operate outside human conscious awareness, such as implicit stereotypes (Greenwald and Banaji, 1995; Nosek et al., 2009), implicit attitudes (Greenwald and Banaji, 1995), automatically activated goals or norms (Bargh, 1997; Bargh and Chartrand, 2000; Bargh et al., 2001; Dijksterhuis et al., 2005), and implicit primary affect (Zajonc, 1980, 2004; Murphy and Zajonc, 1993; Murphy et al., 1995; Jarymowicz and Kobylińska, 2005; Winkielman et al., 2005; Kobylińska and Karwowska, 2007). Most data showing implicit affective stimuli influence on evaluative judgments, come from experiments conducted in an affective priming paradigm. The paradigm was introduced by Murphy and Zajonc (1993) who presented evidence for the existence of unconscious primary affect (Zajonc, 1980) and its influence on cognition. In their original experiments they presented neutral target stimuli (for example Chinese ideographs), which were preceded by either 1-s or 4-ms exposures of photographs of faces expressing either positive or negative emotions. The results showed that suboptimal (4ms) affective primes induced affect that influenced evaluations of the neutral targets. Ideographs primed by negative facial expressions were judged more negatively than those primed by positive ones. Interestingly, neither the facial expression nor even the presence of any image was accessible to the participants’ awareness. In contrast to suboptimal affective primes, both optimal affective primes (exposed for 1 s) and affectively neutral suboptimal primes (e.g., geometric figures of different shapes) failed to influence the participants’ judgments about targets. This was the first effect observed in affective priming research. However, it turned out in later studies that the reverse effect is also possible (Glaser and Banaji, 1999; Ohme et al., 1999). The first effect, when judgments about neutral stimuli are consistent with the valance affective primes, is referred to as the assimilation effect. The reverse effect, when targets primed negatively are evaluated more positively than those primed positively (thus inconsistently with priming valance), is called the contrast effect. It turned out that which of the two effects is obtained is not a matter of chance but is related to important psychological and neurobiological processes occurring at the time when affect is elicited. Both effects are quite simple and both proof that judgmentsmay be influenced by stimuli presented outside conscious awareness. Accordingly, in this opinion article, we will explore the psychological mechanism underlying the effects of assimilation and contrast.