The answers for the observation experiment are as follows:
- 14 passes from white to white;
- 19 passes from black to black;
- A gorilla.
Missed the gorilla? Watch the video again, and try and work out why you didn’t see him first or second time round. It’s called inattentional blindness – your mind ignores events it’s not concentrating on. You can read an overview or see some more demos. The O’Reilly book Mind Hacks by Tom Stafford and Matt Webb also discusses this and similar phenomena.
Of the 17 people who mailed me:
- 8 (47%) didn’t see (or didn’t mention) the gorilla
- 4 (24%) saw him first time
- 3 (18%) saw him second time
- 1 ( 6%) saw him third time
- 1 ( 6%) knew the secret before the start
Update 2005-03-17: This next paragraph is entirely wrong; I had mistakenly turned pass 9 into two passes. So the answers are 14 and 19, and quite a few people got it right.
[Unrelated to the gorilla, almost everyone said 14 for white-to-white passes, which is one short of the true total of 15. Pass 10 is both quick and completely hidden from the camera, but a different person gets the ball, so it must exist :-) Most people correctly got 19 for black-to-black. Congratulations to Onkar Shinde who was the only person to get both numbers correct.]