# Can you see the invisible gorilla?  ## Episode metadata - Episode title: Can you see the invisible gorilla? - Show: Nudge - Owner / Host: Phill Agnew - Episode publish date: 2025-01-20 - Episode AI description: The podcast dives into the famous Invisible Gorilla experiment, revealing how people often miss unexpected events when focused on a task. Listeners participate in an audio version, experiencing inattentional blindness firsthand. It discusses perceptual blind spots, using the tragic collision of ships to highlight the impact on decision-making. Memory distortion's effect on marketing is also examined, showcasing how repeated exposure enhances consumer recall. Overall, it reveals surprising insights about attention and memory in everyday life and marketing. - Mentioned books: [The Invisible Gorilla](https://share.snipd.com/book/1ab02fff-1339-4352-8548-cd0df08d18d0) by [Christopher Chabris](https://share.snipd.com/person/1f7f051f-b6c2-4a86-88c7-565828995b06), [Daniel Simons](https://share.snipd.com/person/0d3c5553-92c1-4ff7-b9ac-11c752bc4ce6), [Nobody's Fool](https://share.snipd.com/book/29020371-afab-424d-91a5-9bcfc9177914) by [Christopher Chabris](https://share.snipd.com/person/1f7f051f-b6c2-4a86-88c7-565828995b06), [Daniel Simons](https://share.snipd.com/person/0d3c5553-92c1-4ff7-b9ac-11c752bc4ce6) - Duration: 26:33 - Episode URL: [Open in Snipd](https://share.snipd.com/episode/3e23a63c-c32f-4074-ab36-89873f187220) - Show URL: [Open in Snipd](https://share.snipd.com/show/368e312d-6ad3-475a-91a9-12d5e97283fb) - Export date: 2026-02-11T20:06:35 ## Snips ### [Inattentional Blindness](https://share.snipd.com/snip/9e9f79a5-0cf3-428a-b958-da99fb2641f8) 🎧 07:32 - 08:10 (00:38) <iframe src="https://share.snipd.com/embed/obsidian-player/snip/ed995262-99b4-4c21-87ec-5241f121a9c6" width="100%" height="100" style="border: none; border-radius: 12px;" sandbox="allow-scripts allow-same-origin allow-forms allow-popups allow-clipboard-write" ></iframe> - People miss unexpected events, even obvious ones, and are shocked when shown what they overlooked. - This reveals our flawed intuition about our awareness, assuming we'd notice important things. #### 💬 Quote > It's that people can miss something so obvious that when they do, they're shocked. When they're shown what they missed, they have a hard time believing that they missed it. > — Dan Simons Dan Simons on the surprising nature of inattentional blindness. #### 📚 Transcript **Phill Agnew:** That's the same amount of time as those who did notice the gorilla. People were looking at the gorilla, yet their brains weren't noticing it. **Dan Simons:** That finding more or less replicates what nicer had shown much earlier, just with a little more vivid displays with a single camera shot. There's no ambiguity about what you'd seen. And what's interesting about it to me is not just that people miss things, because we'd known that people miss things for years. It's that people can miss something so obvious that when they do, they're shocked. When they're shown what they missed, they have a hard time believing that they missed it. And it's that intuition for me that's the really powerful thing. We assume --- ### [Hands-Free Hazard](https://share.snipd.com/snip/6fe5d0f9-2b9a-465f-b02d-30306bfdb9ec) 🎧 08:20 - 09:49 (01:29) <iframe src="https://share.snipd.com/embed/obsidian-player/snip/24f52f66-56d6-4bf2-bec2-3fa09e39f9ee" width="100%" height="100" style="border: none; border-radius: 12px;" sandbox="allow-scripts allow-same-origin allow-forms allow-popups allow-clipboard-write" ></iframe> - Hands-free phone calls triple the likelihood of missing unexpected events, like a gorilla, compared to just a visual task. - Drivers falsely believe hands-free calling doesn't affect driving because they can stay on the road, but miss crucial events. #### 💬 Quote > Simply having a conversation on the phone tripled the chances that they would fail to see something unexpected. [...] The problem is that they're much less likely to notice rare, unexpected, and potentially catastrophic events. > — Phil Agnew Phil Agnew summarizing research on the dangers of hands-free calling while driving, referencing Dan Simons' work. #### 📚 Transcript **Phill Agnew:** Take driving while having a hands-free phone call. We all know that driving while holding a phone next to our ears and having a conversation, well, we know that's wrong. We have one hand off the wheel and that impairs our driving. Hands-free driving, however, is fine, right? Because both hands are on the wheel. Well, Dan disagrees. Additional research on his guerrilla experiment findings show that hands-free phone calls aren't actually that much safer. Brian Scholl and his students at Yale used a variant of the guerrilla experiment to explore the effects of mobile phone conversations on inattention. They compared a group of people who watched the gorilla experiment video as usual with another group who watched the video as usual while simultaneously carrying out a mobile phone conversation. In Brian Scholl's version, he found that 30% of the participants missed the gorilla when they were just doing the counting task, so not having the phone call. However, the participants who watched the video while taking a phone call missed the gorilla 90% of the time. Simply having a conversation on the phone tripled the chances that they would fail to see something unexpected. Dan writes that this sobering finding shows how mobile phone conversations dramatically impair visual perception and awareness. He says the finding may explain why people falsely believe that mobile phones do nothing to affect their driving. People are lured into thinking that they drive fine because they can still perform the primary task of staying on the road properly. --- ### [Joshua Bell's Subway Experiment](https://share.snipd.com/snip/fb8eacb5-bd53-41f9-979e-bc539a9dfbcd) 🎧 11:19 - 12:56 (01:36) <iframe src="https://share.snipd.com/embed/obsidian-player/snip/1fa6c7cc-621e-4a0e-9e87-ea51433e85d1" width="100%" height="100" style="border: none; border-radius: 12px;" sandbox="allow-scripts allow-same-origin allow-forms allow-popups allow-clipboard-write" ></iframe> - World-renowned violinist Joshua Bell busked in a D.C. subway and was largely ignored, earning only $32. - This demonstrates that even extraordinary events can be missed if unexpected, as commuters weren't looking for a famous musician. #### 💬 Quote > Over the course of his 43-minute performance, more than 1,000 people passed within a few feet of him, but only seven stopped to listen. [...] People weren't looking for the world's best violinist, so they didn't spot him. > — Phil Agnew Phil Agnew recounting the Joshua Bell subway experiment, highlighting inattentional blindness. #### 📚 Transcript **Phill Agnew:** On Friday morning rush hour, a busker set up shop between the entrance and an escalator, opened his violin case to take donations, and began performing. However, this wasn't any normal busker. This was the world-famous violinist Joshua Bell. Bell is a bit of a musical prodigy. As a four-year in Indiana, Bell impressed his parents by using rubber bands to pluck out songs he had heard. By the age of 17, Bell had played at Carnegie Hall. In his 20s, he repeatedly topped the classical music charts, receiving numerous awards for his performances, and he even appeared on Sesame Street. The official biography on his website began with the words, Joshua Bell has captured the public's attention like no other classical violinist of his time. But that wasn't the case at the subway stop in Washington. Over the course of his 43-minute performance, more than 1,000 people passed within a few feet of him, but only seven stopped to listen. And not counting a donation of $20 from a passerby who recognised him, Bell only made $32.17 for his work. This was an awful lot less than what he would have made performing for 43 minutes in a concert theatre. This was a genuine surprise to classical music fans. It's like the Arctic Monkeys busking at Oxford Circus and only making enough money to cover the train ride home. --- ### [USS Greenville Collision](https://share.snipd.com/snip/1938ad4f-b581-4c54-aca5-1b442db32764) 🎧 13:47 - 15:17 (01:30) <iframe src="https://share.snipd.com/embed/obsidian-player/snip/73ce83b0-f8ed-494f-9bce-19c5d2c1449e" width="100%" height="100" style="border: none; border-radius: 12px;" sandbox="allow-scripts allow-same-origin allow-forms allow-popups allow-clipboard-write" ></iframe> - The USS Greenville collided with a Japanese fishing vessel because the captain, despite looking, didn't see it. - He wasn't expecting to see a ship there, illustrating that we miss what we don't anticipate, highlighting inattentional blindness. #### 💬 Quote > Commander Waddle looked right towards it, but he still missed it. [...] As he said later, 'I wasn't looking for it, nor did I expect it.' > — Phil Agnew Phil Agnew describing the USS Greenville incident, emphasizing how unexpected events are often missed. #### 📚 Transcript **Phill Agnew:** At the **Dan Simons:** helm, Commander Scott Waddle, the **Phill Agnew:** of the USS Greenville at the time. With one of the visitors seated at the sub's controls, the USS Greenville performed what's called a main ballast blow, a move reserved for emergencies and training. We **Dan Simons:** have a vessel that has had a approximately nine miles, **Phill Agnew:** At 1.40pm on February 9th, 2001, the USS Grenville surfaced at high speed directly under a Japanese fishing vessel. Six people on board the fishing vessel died. But what went wrong? How could a state-of modern-day sub with sonar and an experienced crew not detect a 200-foot fishing ship right above it? Well, it's another invisible gorilla. Commander Waddle made all of the necessary preparations before performing an emergency deep manoeuvre. He lifted the periscope to search for other ships, and the Japanese boat should have been visible through the periscope. Waddell looked right towards it, but he still missed it. Dan writes in his book that the USS Grenville's commanding officer, with all of his experience and expertise, could have looked right at the other ship and not seen it. The key lies in what he thought he would see when he looked. As he said later, I wasn't looking for it, nor did I expect it. We miss what we don't expect. That's why illusions like the invisible gorilla work. --- ### [Illusion of Memory](https://share.snipd.com/snip/e8f8a484-48e4-413d-b938-c042c707e2db) 🎧 16:17 - 17:27 (01:10) <iframe src="https://share.snipd.com/embed/obsidian-player/snip/29c0bfaf-c3d5-4eba-adc9-fee9b965f037" width="100%" height="100" style="border: none; border-radius: 12px;" sandbox="allow-scripts allow-same-origin allow-forms allow-popups allow-clipboard-write" ></iframe> - Our memories are flawed; we often misremember and are unaware of these errors. - We base our intuitions on conscious experiences, not what we miss, leading to overconfidence in our memory. #### 💬 Quote > If you go to movies a lot and you spot errors in them, you might assume that you always notice errors because you're only aware of the errors you spotted. You don't know about the hundreds you've missed. > — Dan Simons Dan Simons explaining how our intuitions about memory are based on what we notice, not what we miss. #### 📚 Transcript **Phill Agnew:** Hello and welcome back to Nudge with me, Phil Agnew. Dan has shared how we miss the unexpected, like a gorilla in a video. But this illusion has come with some interesting consequences. **Dan Simons:** If I ran the gorilla study, I showed it to you, you'd never seen it before, I don't ask you about a gorilla. And you miss the gorilla and I don't ask you about it. You'd continue going through life assuming that of course you would see a gorilla in a video. You continue to go through life assuming that something important will grab my attention, because you're aware of those cases you notice. If you go to movies a lot and you spot errors in them, you might assume that you always notice errors because you're only aware of the errors you spotted. You don't know about the hundreds you've missed. So our intuitions are built up from these experiences of these positive events, but we don't think about what we're missing. And that's a really potent thing. It actually leads into what we talk about for deception, that our habit of focus, we to focus on the information we have and not to think much about the information we don't have. So our intuitions are built up from this experience that we have of what's right in front of us, not from the information that's lacking. --- ### [Challenger Explosion Memory Distortion](https://share.snipd.com/snip/73ca71bb-52cc-43e6-8d81-1f3fef1bcbda) 🎧 19:08 - 20:34 (01:26) <iframe src="https://share.snipd.com/embed/obsidian-player/snip/f7a7b3f0-faee-4398-b673-2832e355dc95" width="100%" height="100" style="border: none; border-radius: 12px;" sandbox="allow-scripts allow-same-origin allow-forms allow-popups allow-clipboard-write" ></iframe> - Psychologists Ulrich Neisser and Nicole Harsh surveyed Emory University students about how they learned of the Challenger explosion. - 2.5 years later, they resurveyed the students, finding significant memory distortions. - One student falsely recalled someone shouting the news down a hallway, another a friend calling from Switzerland. - When shown their original responses, many students were shocked by the discrepancies but still clung to their distorted memories. #### 💬 Quote > Many were shocked at the discrepancy between their original reports and their memories of what had happened. > — Phill Agnew Phill Agnew on memory distortion after the Challenger explosion. #### 📚 Transcript **Phill Agnew:** There are more examples like this. On the morning of January 28th, 1986, the space shuttle Challenger exploded shortly after takeoff. The very next morning, psychologists Ulrich Neisser and Nicole Harsh asked a class of Emory University undergraduates to write a description of how they heard about the explosion and then to answer a set of detailed questions about the disaster. Two and a half years later, Nysa and Harsh asked the same students to complete a similar questionnaire about the Challenger explosion. The students' memories of events had changed dramatically over the time. One remembered somebody shouting the news at them down a hallway, but that never happened. Another remembered being called by a friend in Switzerland to be told about the explosion, but that memory was totally imagined as well. Neisser and Haar showed the subjects their own handwritten answers to the questionnaire from the day after the Challenger explosion. Many were shocked at the discrepancy between their original reports and their memories of what had happened. Dan writes that when confronted with their original reports, rather than suddenly realising that they had misremembered, many often persisted in believing their current memory rather than the real event. Now, I'm a marketer and I can't help but think about the implications all of this has for marketing. We marketers believe that sticking up a billboard in a busy tube station will mean that thousands of people who walk past will notice it. --- ### [Repetition in Advertising](https://share.snipd.com/snip/d4796041-7820-4991-bdc5-2276b52eef49) 🎧 20:20 - 25:02 (04:42) <iframe src="https://share.snipd.com/embed/obsidian-player/snip/202139ae-82dc-4f8c-802d-6ba65af4613f" width="100%" height="100" style="border: none; border-radius: 12px;" sandbox="allow-scripts allow-same-origin allow-forms allow-popups allow-clipboard-write" ></iframe> - Multiple exposures are crucial for ad memorability, not just distinctiveness. - Repeatedly seeing the gorilla or Joshua Bell busking regularly would increase noticeability. #### 💬 Quote > It's repeat exposure that makes an ad memorable. [...] If Joshua Bell performed at the L'Enfant Plaza subway stop [...] every single week, the performance would eventually draw in massive crowds. > — Phil Agnew Phil Agnew discussing the importance of repetition in advertising for better recall. #### 📚 Transcript **Phill Agnew:** Now, I'm a marketer and I can't help but think about the implications all of this has for marketing. We marketers believe that sticking up a billboard in a busy tube station will mean that thousands of people who walk past will notice it. But as Joshua Bell showed, even extremely unexpected events like a prolific musician won't be enough to capture the attention of busy commuters. I've perhaps naively shared on this podcast before that a distinctive ad will capture attention, but more often than not, even unexpected things like a gorilla staring at you and thumping its chest will avoid our attention. So I wondered, how many ads do the typical commuters remember? What ads are able to break through our heads and get remembered, and why? Well, to find out, I took a look at the studies. Now a quick google search brings up a morning brew report which backs up Dan's findings. The paper by Provoke Insights asked 1,500 Americans how many ads they remembered seeing over the past 24 hours. It turns out that most Americans say they only remembered between 1 and 10 percent of the ads they'd seen in the past 24 hours. Another 20 percent said they remembered between 11 and 25% and 16% said they remembered up to 50% of the ads they'd seen. But there's a real problem with this study. This is self-reported recall. The researchers weren't able to actually check how many of these Americans really remembered the ads. It wasn't a randomized controlled trial and because of that I think these results are quite meaningless. Fortunately, other scientists, Osborne and Coleman, conducted a far more reliable study on outdoor advertising. For their study, the researchers spoke to 517 adults in a mid-sized southeastern US city who drove along a one-mile stretch of the city's main interstate at least once a week. The researchers knew when the drivers took this drive and could cross-reference their recall with the actual ads on the main interstate. So this is more reliable, let's see what the results are. Well, when prompted by the name of the advertiser, 66 respondents recalled the TriVision board. The TriVision board is one billboard with three rotating sides, all for one advertiser. Two other billboards received 60% or greater aided recalls. Four more boards were remembered by 50% of the respondents and another four boards were recalled by more than 40%. All of the boards were recorded by at least some respondents with the lowest rate of aided recall at 7% for a deer management company and 6% for a firm Bits Computers. The best billboards were these tri-vision ones with multiple messages for one advertiser. According to the researcher, worked best because of the repeat exposure, because the repeat exposure gave the message time to sink in. The worst billboards were actually smart TV billboards, with just 6% aided recall. The researchers write that this low recall is due to the low repetition. The smart boards rotated multiple advertisers at eight second intervals, meaning each advertiser was only briefly viewed. And it's the exposure that really seems critical to increasing recall. Further analysis by Osborne and Coleman found that there was a significant difference in aided recall based on the length of the campaign, with longer campaigns, campaigns that had been running for a lot longer, had a much greater recall. And this finding compounds because once drivers were aware of a product or service, they were significantly more likely to remember it. It's repeat exposure that makes an ad memorable. If you watch the gorilla video more than once, you'll almost certainly see the gorilla. If you listen to Polly Dalton's audio version twice, you'll definitely hear the I am a gorilla man. It's multiple exposure that causes recall, causes memory. If Joshua Bell performed at the L'Enfant Plaza subway stop in Washington DC every single week, the performance would eventually draw in massive crowds. And yet many marketers forget this. We believe that people notice the unexpected. Just like the 75% of Americans who believe they'll spot an unexpected event, we believe American commuters will spot one distinctive ad. But they don't. To be remembered correctly, you need multiple exposures. There is no silver bullet when it comes to marketing. It's a long, expensive slog that requires an extraordinary amount of visibility. We can dream of viral videos and effective click funnels, but that fallacy goes against all evidence. Dan Simons, Joshua Bell and Commander Waddle reveal the truth. --- ### [Tri-Vision Billboards for Repeated Exposure](https://share.snipd.com/snip/70448a0e-f113-447e-af5c-331d9fcda137) 🎧 22:57 - 23:31 (00:34) <iframe src="https://share.snipd.com/embed/obsidian-player/snip/c65a3b7d-a43d-4ee3-b9fe-0c7758e22d56" width="100%" height="100" style="border: none; border-radius: 12px;" sandbox="allow-scripts allow-same-origin allow-forms allow-popups allow-clipboard-write" ></iframe> - Tri-vision billboards, with their rotating three-sided displays for a single advertiser, achieve higher recall rates than standard billboards. - This effectiveness is attributed to repeated exposure, allowing the message to resonate with viewers over time. - In contrast, smart billboards that rotate multiple advertisers quickly have lower recall due to limited exposure. #### 💬 Quote > The best billboards were these tri-vision ones with multiple messages for one advertiser. [...] [They] worked best because of the repeat exposure. > — Phill Agnew Phill Agnew summarizing findings from Osborne and Coleman's study on outdoor advertising recall. #### 📚 Transcript **Phill Agnew:** The best billboards were these tri-vision ones with multiple messages for one advertiser. According to the researcher, worked best because of the repeat exposure, because the repeat exposure gave the message time to sink in. The worst billboards were actually billboards, TV billboards, with just 6% aided recall. The researchers write that this low recall is due to the low repetition. The smart boards rotated multiple advertisers at eight second intervals, meaning each advertiser was only briefly viewed. --- Created with [Snipd](https://www.snipd.com) | Highlight & Take Notes from Podcasts