Two bases of the compatibility effect in the Implicit Association Test (IAT)

Area of Science:

• Cognitive Psychology
• Social Psychology
• Psychometric Methods

Background:

• The Implicit Association Test (IAT) is a widely used measure of implicit attitudes and biases.
• The compatibility effect in IATs, where reaction times differ based on stimulus-category pairings, is a key phenomenon.
• The underlying mechanisms of the IAT compatibility effect, particularly the roles of valence and familiarity, require further investigation.

Purpose of the Study:

• To investigate the mechanisms underlying the compatibility effect in the Implicit Association Test (IAT).
• To empirically dissociate IAT effects based on valence from those based on familiarity.
• To compare the differential impact of experimental manipulations on valence-based and familiarity-based IATs.

Main Methods:

• Four experiments were conducted using two types of IATs: a flower IAT (flowers vs. insects) and a number IAT (even vs. odd numbers).
• Standard IAT procedures, as well as modified procedures by Klauer and Mierke (2005) and Rothermund and Wentura (2004), were employed.
• Stimulus materials were chosen to create differential valence contrast between categories in the flower and number IATs.

Main Results:

• Experiment 1 showed equal IAT effects for both flower and number IATs, despite differences in rated valence contrast.
• Experiment 2 indicated that valence plays a role in the flower IAT but not the number IAT.
• Experiments 3 and 4 demonstrated that specific manipulations affected the flower and number IATs differently, supporting dissociable mechanisms.

Conclusions:

• The results provide converging evidence that IAT effects based on valence and familiarity are empirically dissociable.
• Different mechanisms underlie the compatibility effect in different types of IATs.
• The findings contribute to a better understanding of the psychometric properties and underlying processes of the IAT.