The Impact of Multisensory Exposure on Sound-Symbol Associations in Domestic Chicks (Gallus gallus)

The Bouba-Kiki Effect describes the tendency to associate spiky shapes with the non-word “kiki” and round shapes with the non-word “bouba.” This phenomenon has been consistently observed in humans across diverse cultures and languages. Previous research has also demonstrated a similar effect in domestic chicks (Gallus gallus) with no prior exposure to these sounds or shapes. This study empirically investigates whether sound-shape associations influenced by previous experience to the shapes and sounds. To this aim we tested three-day-old domestic chicks following several hours of cross-modal exposure under various experimental conditions. Specifically, the experiment examines whether the effect can be modulated by a congruent condition—where exposure to round shapes is paired with the sound 'bubu' and exposure to spiky shapes with the sound 'kiki'—in which the effect is expected to persist, and an incongruent condition, which is hypothesized to weaken or reverse the effect. The study aims to determine whether this environmental conditioning is strong enough to override the previously established Bouba-Kiki Effect or whether the effect remains robust.