Dogs seem to agree with humans that 'bouba' is round and 'kiki' is spiky
Experiments suggest that dogs, like humans and even baby chicks, tend to match the nonsense word “bouba” with rounded shapes and “kiki” with spiky ones, hinting at a deep cross‑sensory link between sound and visual form. Commenters explore how properties of speech sounds (voiced vs. unvoiced plosives, attack/decay, frequency content) might map naturally onto notions of sharpness and softness, and whether this reflects shared neural “latent spaces” across senses or evolutionary constraints. Others scrutinize the experimental design for issues like owner cueing (the Clever Hans effect), debate how universal such sound–shape symbolism really is across languages and species, and connect it to phenomena like synesthesia and onomatopoeia.
Phonetics and Perceptual “Sharpness”
- Many note that “kiki” feels sharp and “bouba” feels soft due to articulation:
- K is an unvoiced plosive made further back in the mouth, producing abrupt, high‑energy transients.
- B is a voiced plosive at the lips, with smoother onsets and a “rounder” sound.
- Vowel shapes matter too: /i/ requires a tighter, “pointier” mouth; /u/ or /ou/ uses rounded lips.
- Several commenters link this to continuity vs discontinuity:
- Bouba’s sound and the rounded shape both have smoothly varying “curvature.”
- Kiki’s sound and spiky shapes both involve sudden changes or “corners.”
Cross-Modal Mapping and Synesthesia
- Multiple people argue the brain may use a shared latent space across senses, making “sharp” vs “round” naturally cross-modal.
- Some describe personal synesthetic experiences (numbers or words having shapes, colors, tastes, or spatial layouts), seeing bouba/kiki as a mild, near-universal version.
- Others ask why “sharpness” in sound and shape are linked at all, noting that intuitive explanations (mouth shape, vocal cord shape) feel incomplete.
Dogs, Experimental Design, and Clever Hans Concerns
- Commenters worry dogs could be cued by owners (Clever Hans effect).
- Others point out the study’s second condition: owners wore loud music headphones to reduce such cues, though gaze cues might still remain.
- One person criticizes the small sample size (19 dogs) as low statistical power.
Universality, Evolution, and Other Species
- References to prior work show similar bouba/kiki effects in newly hatched chicks, suggesting minimal learning is required.
- Some speculate early nervous systems might have processed different energy waves (sound/light) with shared machinery, leading to conserved “smooth vs jagged” coding.
Language, Culture, and Onomatopoeia
- Discussion of voiced vs unvoiced plosives, tonal languages, and languages lacking certain sounds questions how universal the phonetic basis really is.
- Others link this to broader sound symbolism: curse words tending toward “hard” consonants; product or shape names using round vs sharp vowels; cross-language animal sounds differing yet still systematically mapped.
Color/Taste and Personal Associations
- Several participants report idiosyncratic color assignments for “kiki” and “bouba,” and some describe number–taste or number–space mappings.
- These are viewed as more arbitrary than the bouba/kiki shape mapping, which shows broad agreement.