# Is Kiki angry and Bouba happy? Association between emotions, shapes, and sounds

**Authors:** Lari Vainio, Xinyuan Mo, Martti Vainio

PMC · DOI: 10.1007/s00426-025-02158-5 · Psychological Research · 2025-07-14

## TL;DR

The study explores how people associate emotions with shapes and sounds, finding that emotional associations are implicit for shapes but not for sounds.

## Contribution

The study distinguishes between explicit and implicit emotional mediation in the kiki-bouba effect.

## Key findings

- Angular shapes are implicitly linked to anger, while round shapes are linked to happiness and calmness.
- Emotional associations with kiki/bouba-like words are explicit but not implicit.
- The kiki-bouba effect in implicit tests is not based on emotional mediation.

## Abstract

Research has shown that particular shapes and speech sounds have common higher-order emotional properties, which might mediate associating angular shapes with kiki-like words and round shapes with bouba-like words, resulting in the so-called kiki-bouba effect. However, research supporting this account has mostly recruited explicit association tests to investigate whether people link particular emotions with these shapes and pseudo-words. This study investigated whether the kiki-bouba effect, observed in the implicit association test, can be similarly based on these emotional mediation processes. We found that the explicit and implicit association tests robustly produced a link between angular shape and angry facial expressions, whereas the round shape was associated with happy and calm facial expressions. In contrast, aurally presented kiki and bouba-like words were associated with these facial expressions in the explicit association test but not in the implicit association test. These observations suggest that people process implicitly the emotional properties of angular/round shapes, while they do not automatically process the emotional properties of the perceived kiki/bouba-like words when the task emphasizes implicit association processes. Consequently, we propose that the kiki-bouba effect, which is observed in explicit association tests, can be partially based on emotional mediation processes. In contrast, the kiki-bouba effect, which is based on implicitly operating association processes, is not likely to be based on emotional mediation processes.

## Full-text entities

- **Diseases:** pain (MESH:D010146), HD (MESH:D006816)
- **Chemicals:** emoji (-)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Full text

_Full body text omitted from this summary view._ Fetch the complete paper as Markdown: https://tomesphere.com/paper/PMC12259753/full.md

## Figures

4 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12259753/full.md

## References

3 references — full list in the complete paper: https://tomesphere.com/paper/PMC12259753/full.md

---
Source: https://tomesphere.com/paper/PMC12259753