Bouba or kiki?.
Which of these two shapes is called 'bouba'?
Original study
- Köhler, W. (1929). Gestalt psychology. New York: Liveright. Source
- Ramachandran, V. S., & Hubbard, E. M. (2001). Synaesthesia: A window into perception, thought and language. Journal of Consciousness Studies, 8(12), 3–34. Source
- Maurer, D., Pathman, T., & Mondloch, C. J. (2006). The shape of boubas: Sound–shape correspondences in toddlers and adults. Developmental Science, 9(3), 316–322. Source
- Ćwiek, A., Fuchs, S., Draxler, C., Asu, E. L., Dediu, D., Hiovain, K., Kawahara, S., Koutalidis, S., Krifka, M., Lippus, P., Lupyan, G., Oh, G. E., Paul, J., Petrone, C., Ridouane, R., Reiter, S., Schümchen, N., Szalontai, Á., Ünal-Logacev, Ö., Zeller, J., Perlman, M., & Winter, B. (2022). The bouba/kiki effect is robust across cultures and writing systems. Philosophical Transactions of the Royal Society B, 377(1841), 20200390. Source
- Styles, S. J., & Gawne, L. (2017). When does maluma/takete fail? Two key failures and a meta-analysis suggest that phonology and phonotactics matter. i-Perception, 8(4), 2041669517724807. Source
- Fort, M., & Schwartz, J.-L. (2022). Resolving the bouba-kiki effect enigma by rooting iconic sound symbolism in physical properties of round and spiky objects. Scientific Reports, 12, 19172. Source
- Köhler, W. (1947). Gestalt psychology: An introduction to new concepts in modern psychology (2nd ed.). New York: Liveright. Source
- Sapir, E. (1929). A study in phonetic symbolism. Journal of Experimental Psychology, 12(3), 225–239. Source
- Nielsen, A., & Rendall, D. (2011). The sound of round: Evaluating the sound-symbolic role of consonants in the classic Takete-Maluma phenomenon. Canadian Journal of Experimental Psychology, 65(2), 115–124. Source
- D'Onofrio, A. (2014). Phonetic detail and dimensionality in sound-shape correspondences: Refining the bouba-kiki paradigm. Language and Speech, 57(3), 367–393. Source
Our adaptation
A written adaptation of the sound–shape matching task of Köhler (1929) and Ramachandran and Hubbard (2001). In round 1 a round, blob-like shape and a spiky, star-like shape (same size and color) are shown with a random left-right placement, and the participant chooses which one is 'bouba'; the pronunciation ('buba') is written under the word. Round 2 asks Köhler's 'takete' question, round 3 asks to match four made-up words (lula, kitiki, momo, zizi) with four shapes ranging from round to spiky, and round 4 asks to match Sapir's 'mil' and 'mal' with a small and a large circle. After answering, participants are asked whether they had seen the test before.
Differences from the original study
- Words are shown in writing, not played aloud; Ćwiek et al. (2022) played the words and scored two matches together.
- The test is widely known online; prior knowledge is separated only by self-report.
- The four rounds follow each other for the same person; someone who notices the rule in round 1 may follow it later.
Measured variables
The columns of the open data file. List fields are expanded into numbered columns (for example rt_60, est_3); JSON columns contain only numbers and fixed stimulus names.
| Column | Type | Description |
|---|---|---|
pick | round | spiky | Round 1: shape chosen as 'bouba' (round | spiky). |
side | left | right | Round 1: screen side of the chosen shape (left | right), to check for position bias. |
takete | round | spiky | Round 2: shape chosen as 'takete' (expected: spiky). |
match | integer | Round 3: number of the four words matched in the expected direction (lula and momo to the two round shapes, kitiki and zizi to the two spiky ones; 0–4). |
word_shape_lula | number | Round 3: shape given to the word; 0 = roundest … 3 = spikiest. (lula) |
word_shape_kitiki | number | Round 3: shape given to the word; 0 = roundest … 3 = spikiest. (kitiki) |
word_shape_momo | number | Round 3: shape given to the word; 0 = roundest … 3 = spikiest. (momo) |
word_shape_zizi | number | Round 3: shape given to the word; 0 = roundest … 3 = spikiest. (zizi) |
mil | small | big | Round 4: circle chosen as 'mil' (small | big; expected: small). |
Columns present in every file (14)
row_id | string | Row code. Regenerated at random in every release; it does not identify a person and cannot be matched across releases or experiments. |
experiment | string | Short name of the experiment (URL slug). |
experiment_version | integer | Version of the answer format. For experiments whose format changed, only the current format is published. |
date | YYYY-MM-DD | YYYY-Www | YYYY-MM | Day the answer was given (Istanbul time). If fewer than 5 answers share the same day, language and device, it is coarsened to the ISO week, and to the month if that is still too few. |
date_precision | day | week | month | Precision of the date column. |
lang | tr | en | (boş) | Interface language. Language recording started in the first week of October 2026; for earlier answers it is known only in experiments whose stimuli depend on the language, and empty otherwise. |
device | desktop | mobile | tablet | (boş) | Device class reported by the browser (class only; browser details are neither stored here nor published). |
source | site | embed | Where the answer came from: the balabs site or the experiment embedded on another site. The embedding site is not published. |
mode | free | daily | challenge | race | session | (boş) | Play mode in scored experiments: free play, daily round, challenge, race room, experiment session. Empty for unscored experiments and for older answers that did not store it. |
color_vision | normal | rg | by | contrast | (boş) | In color-based experiments, the color vision mode the participant chose: normal, red-green, blue-yellow or high contrast. Stimuli are generated along different axes per mode, so compare within a mode. Empty for other experiments. |
first_play | 1 | Every row is a participant’s first play of this experiment (always 1). Replays are stored only as leaderboard scores and are not part of the open data. |
seen_before | yes | no | unsure | (boş) | Participant’s own report of whether they had seen this experiment or its known answer before (in experiments that ask). |
duration_s | number | Time from the start of the experiment to submitting the answer, in seconds (measured in the browser, 0.1 s). |
play_score | number | Leaderboard score of the first play (scored experiments; defined on the method card). Empty for unscored experiments. |
Exclusion criteria
The server requires the round-1 choice (round | spiky); invalid answers are rejected. Values from the extra rounds are collected in the browser. We recommend reporting participants who say they had seen the test before (seen_before) separately.
- Only each participant's first answer to this experiment; replays are not included.
- Simulated rows, bots, banned and sample accounts are not included.
- Answers before 3 October 2026 are not included (the first day the open data notice was live).
Scoring
This experiment has no leaderboard score. The crowd result is the share of participants making the expected match in each round.
Version notes
- October 2026
The interface language (lang) started being stored with each answer; for earlier answers it is known only in experiments whose stimuli depend on the language, and empty otherwise.