How many people are like you?.
Make six everyday choices, then estimate: what percentage of the people who come here made the same choice as you?
Original study
- Ross, L., Greene, D., & House, P. (1977). The “false consensus effect”: An egocentric bias in social perception and attribution processes. Journal of Experimental Social Psychology, 13(3), 279–301. Source
- Mullen, B., Atkins, J. L., Champion, D. S., Edwards, C., Hardy, D., Story, J. E., & Vanderklok, M. (1985). The false consensus effect: A meta-analysis of 115 hypothesis tests. Journal of Experimental Social Psychology, 21(3), 262–283. Source
- Marks, G., & Miller, N. (1987). Ten years of research on the false-consensus effect: An empirical and theoretical review. Psychological Bulletin, 102(1), 72–90. Source
- Dawes, R. M. (1989). Statistical criteria for establishing a truly false consensus effect. Journal of Experimental Social Psychology, 25(1), 1–17. Source
- Krueger, J., & Clement, R. W. (1994). The truly false consensus effect: An ineradicable and egocentric bias in social perception. Journal of Personality and Social Psychology, 67(4), 596–610. Source
- Engelmann, D., & Strobel, M. (2000). The false consensus effect disappears if representative information and monetary incentives are given. Experimental Economics, 3(3), 241–260. Source
Our adaptation
An adaptation of the false consensus effect of Ross, Greene and House (1977) with six everyday preferences. For each question one of two options is chosen first (left-right position randomized), then a 0–100 slider with no default position is used to estimate what percentage of participants made the same choice. The true shares are not shown until all questions are answered.
Differences from the original study
- The 'true share' is that of participants on this site, not of a population.
- The questions are light, everyday preferences.
- In the original, estimates were collected for both options; here only for one's own option.
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_1 | a | b | Option chosen for the question (a = first, b = second option; in question order: tea / coffee, morning person / night person, pineapple pizza yes / never, sea / mountains, film / series, phone on silent / sound on); the number at the end of the column is the question order. (item 1) |
pick_2 | a | b | Option chosen for the question (a = first, b = second option; in question order: tea / coffee, morning person / night person, pineapple pizza yes / never, sea / mountains, film / series, phone on silent / sound on); the number at the end of the column is the question order. (item 2) |
pick_3 | a | b | Option chosen for the question (a = first, b = second option; in question order: tea / coffee, morning person / night person, pineapple pizza yes / never, sea / mountains, film / series, phone on silent / sound on); the number at the end of the column is the question order. (item 3) |
pick_4 | a | b | Option chosen for the question (a = first, b = second option; in question order: tea / coffee, morning person / night person, pineapple pizza yes / never, sea / mountains, film / series, phone on silent / sound on); the number at the end of the column is the question order. (item 4) |
pick_5 | a | b | Option chosen for the question (a = first, b = second option; in question order: tea / coffee, morning person / night person, pineapple pizza yes / never, sea / mountains, film / series, phone on silent / sound on); the number at the end of the column is the question order. (item 5) |
pick_6 | a | b | Option chosen for the question (a = first, b = second option; in question order: tea / coffee, morning person / night person, pineapple pizza yes / never, sea / mountains, film / series, phone on silent / sound on); the number at the end of the column is the question order. (item 6) |
est_1 | integer | Estimate of the percentage choosing the participant's own option (0–100). (item 1) |
est_2 | integer | Estimate of the percentage choosing the participant's own option (0–100). (item 2) |
est_3 | integer | Estimate of the percentage choosing the participant's own option (0–100). (item 3) |
est_4 | integer | Estimate of the percentage choosing the participant's own option (0–100). (item 4) |
est_5 | integer | Estimate of the percentage choosing the participant's own option (0–100). (item 5) |
est_6 | integer | Estimate of the percentage choosing the participant's own option (0–100). (item 6) |
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 a choice and a whole-number estimate from 0 to 100 for all six questions; incomplete submissions are rejected.
- 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
Leaderboard score: the mean absolute deviation (points) of the estimates from the true share among other participants (excluding the participant's own answer), if the true share is available for at least 3 questions. Lower is better. Because the true share changes with the crowd, play_score is the value at the time of answering.
Leaderboard measure: reading error (lower is better). The play_score column in the open data is this score for the first play.
Version notes
- October 2026
This experiment started storing the play mode (free, daily, challenge, race, session) with the answer; the mode column is empty for earlier answers.
- 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.