Implicit Revolution 2: Testing Our Implicit Associations


Learn the story of a small group of scientists, the test they developed to reveal implicit processes of the mind, and how they shared it with the world.

Before you listen…

First check out Implicit Revolution 1: How We Develop Implicit Bias


NARRATOR: We are captivated by the idea of mind-reading. Movies like X-Men, TV shows like Star Trek – these all portray worlds where it’s possible to look inside another person’s brain and know what’s happening in their mind.

SPOCK [from STAR TREK]: “Our minds are merging, doctor. Our minds are one. I feel what you feel. I know what you know.”

NARRATOR: Now, much of this is the fantastic stuff of science fiction… but in some ways, it’s just the stuff of science.

In today’s podcast, Part 2 of the Implicit Revolution, we’re exploring the story of a small group of scientists, the device they developed to reveal implicit processes of the mind, and how they harnessed the birth of the internet to share it with the world. Welcome to Outsmarting Human Minds.

MAHZARIN BANAJI: Imagine this: you are asked to shuffle a deck of cards with hearts and diamonds to the left, and with clubs and spades to the right. This is not hard. It takes me under 20 seconds to do this.

NARRATOR: This is Professor Mahzarin Banaji. She’s describing the task that would eventually inspire the IAT – the Implicit Association Test. Visualize it, and you’ll immediately realize what makes it so easy. Hearts and diamonds are red. Clubs and spades are black. You could sort them perfectly without ever looking at the shapes at all.

MAHZARIN BANAJI: Now imagine that I have to sort clubs and hearts to the left, and spades and diamonds to the right. Not hard in the bigger scheme of things, but much harder than the previous sorting. The previous sorting relied on an association between hearts and diamonds: their redness. And I don’t have that prop anymore.

NARRATOR: You can still do the task. But now it’s harder; now color is working against you, and you really have to think about what you’re doing. This was the “aha” moment for psychologist Tony Greenwald and his colleagues. Because thinking deliberately will ensure that you’re sorting the cards correctly… but it’s also going to slow you down. And that means that one way to measure the mind is to measure time.

The IAT came out of this realization. Instead of just shapes, it asks people to sort things or concepts or people, and uses time to calculate how strong different associations are. The faster the sorting, the stronger the implicit association.

Here’s an example. The first IAT simply asked people to sort pictures of flowers and insects with either good words:

MAHZARIN BANAJI: Words like sunshine and love and peace and joy and things like that…

NARRATOR: …or bad words:

MAHZARIN BANAJI: evil, bomb, war, vomit…

NARRATOR: One pairing is a lot easier than the other. I probably don’t even have to tell you which one; just ask yourself: which one is easier to sort with ‘vomit’ – tulip, or cockroach?

That pairing will be faster – maybe just by a few milliseconds, maybe by a few hundred. Just how much faster reveals how strong the association is.

And once they had the test, the questions were endless.

MAHZARIN BANAJI: Every day, we’d come up with new ideas for new experiments we could try out on ourselves. We’d say, “I wonder how it will come out if I take a test for lobster versus anchovy.”

NARRATOR: And then, just like that, you could go from testing innocent preferences for anchovies or sports teams to discovering hidden biases for things like age, weight, and race.

MAHZARIN BANAJI: The first test I ever took was the race test. For half the trials, the light-skinned faces and good words were associated while dark skinned faces and bad words were associated. And I did that one first, and I did that one flawlessly. And I knew that the opposite pairing would be equally easy for me: white and bad, black and good – why should that be any different than the one before?

So I was quite stunned when my fingers almost couldn’t find their way on the keyboard. When I couldn’t keep in mind which had to go where. I made many more mistakes. I took one and a half times as long to do it. And as you can imagine, by the end of this three-minute experience, I was in a sweat. And my first thought was “something is screwed up with this test, because it can’t be me. I know my mind.”

NARRATOR: But it wasn’t the test. Mahzarin and Tony tested themselves again and again – each time getting the same result . They shared it with friends and family, the students in their labs, fellow scientists at conferences. The results were clear: somehow, the IAT was able to bypass conscious belief and reveal implicit associations they didn’t even know they had. Mahzarin and Tony began joking:

MAHZARIN BANAJI: These effects are so big, you could even pick it up on the Internet.

NARRATOR: In 1998, the internet was this barren, unknown thing – teeming with potential, but something that few people knew how to navigate. It was Brian Nosek, then a graduate student in Mahzarin’s lab, who turned joke into reality.

MAHZARIN BANAJI: He had come with a joint degree in Computer Science and Women’s Studies. And he just said, “this can be done.”

NARRATOR: Here’s Brian, now a Professor of Psychology at the University of Virginia, and Executive Director of the Center for Open Science:

BRIAN NOSEK: Mahzarin was convinced earlier, but she knew Tony needed to be convinced too, and he doesn’t convince easily. But the way he told me that he was convinced was he sent me a note saying, “Okay, I’ve scheduled a press conference for six weeks from now. Go get it done.”

It was terrifying because I had been saying, ‘Oh, I can build this, I can build this, I was a computer engineer, I know I could build something for the Internet.’ I had never made anything for the internet prior to that, I had never written in Java, I had very little experience with HTML, for goodness sake, which is the basics of making webpages. So you know, I was talking big, and he called me on it, and so I just stopped sleeping, and I started right then just building this website as fast as I could.

NARRATOR: Between Mahzarin and Brian, there are a flurry of anecdotes: stories about sweating in the un-air-conditioned basement of the Yale Psychology building, about eating pizza with one hand while programming with the other, of sleepless nights and countless bugs – but suffice it to say:

MAHZARIN BANAJI: We made the deadline.

BRIAN NOSEK: It got done, like, the day we were going to the airport to fly to Seattle for the press conference. I don’t even remember the details anymore, other than the terror that it inflicted on me.

MAHZARIN BANAJI: We had talked about what the response would be. And given what the web was at the time, it seemed to us an extravagant prediction that in a year, we would have 500 people take the test. We thought, “wouldn’t that be amazing.”

BRIAN NOSEK: I had it set it up where I could watch the tests come in. And I probably sat there for two hours watching them come in, just coming to the realization of “Th- This is big.”

MAHZARIN BANAJI: We had 45,000 completed tests in the first month. I think we crashed the Yale site, like, several times in the first week.

BRIAN NOSEK: And we’re thinking, “Oh my – oh my gosh! What just happened?”

NARRATOR: The IAT went viral. Mahzarin knew this after a flight she was on, where a pig farmer she was sitting next to heard she was a psychologist, put his fingers on an imaginary keyboard, and asked her:

MAHZARIN BANAJI: “Left-right, black-white – do you know that test?”

NARRATOR: The link to the site had been sent to him by another pig farmer.

MAHZARIN BANAJI: And that’s when I knew that this was out of our hands, that there was something about this that was intriguing enough, depressing enough, challenging enough, but ultimately something that people were going to keep going back to, because they wanted to be the good people that they thought they were.

I have been really humbled by people’s responses, because I don’t believe that I would have dealt with it as well as many people have. I know I didn’t deal with it well when I showed race bias. I’m usually amazed at the people who get it right away.

NARRATOR: What Mahzarin means by “getting it right away” is understanding that our culture and our experience shape what we implicitly learn. And that this learning has consequences.

Over 20 million tests have been completed since the IAT launched, and the data show us some incredible things. For instance, a 2009 study led by Brian found that if you look at how much an entire country implicitly associates “science” with “male” rather than “female” – this average predicts sex differences in 8th grade science and math achievement nationwide. The following year, Matthew Nock and his colleagues measured implicit associations of “self” with “death” and “suicide” in over 100 people seeking treatment at a psychiatric emergency department. They found that the strength of this association predicted whether a high-risk individual would attempt suicide in the next 6 months better than known clinical risk factors such as depression or previous history of suicide attempt.

The data also tell us that we as a society are changing:

MAHZARIN BANAJI: Our attitudes are elastic. They can stretch and accommodate new information that will change them – change our feelings about groups of people other than our own.

If you look at the data over the last ten years or so, we’re seeing a 37% decrease in implicit bias towards gay people. We’re heading towards neutrality. We see this too for race – that bias has gone down by about 13%. We’ve never seen this before. We’ve never seen strong, clear evidence that our implicit attitudes are changing.

NARRATOR: Of course, this doesn’t mean that listening to one 10-minute podcast or going to a single seminar is going to get rid of associations that have been reinforced for decades. Our minds are smarter than that.

MAHZARIN BANAJI: Instead, what we should be thinking about is “how do I change my daily environment so that the props in it routinely allow me to have the thoughts and activate the beliefs that I know are the right ones, that I know are in the interest of my society and me, are in the interest of the students that I teach?”

The outside does get inside, and what we’re observing in these data on change gives me great optimism, because it says that as our world changes, we and our minds will reflect that change.

NARRATOR: Change isn’t necessarily fast; and creating lasting change isn’t easy. But if we are motivated, we can learn to unlearn our biases – the ones that we ourselves don’t want. And that is something worth working towards.

Outsmarting Human Minds is a program founded by Mahzarin Banaji, devoted to improving decision-making using insights from psychological science. Support for this episode was provided by PwC and Harvard University. This episode was developed by Olivia Kang and Mahzarin Banaji, and featured Professors Mahzarin Banaji and Brian Nosek. Sound editing and mixing was done by Evan Younger. Music was composed by Miracles of Modern Science. You can take the Implicit Association Test at For references and related materials, go to


Subscribe to Outsmarting Implicit Bias


Key takeaways from this module

Dive deeper

Extra materials if you want to learn more


The Implicit Revolution Part 2 was created and developed by Mahzarin Banaji and Olivia Kang with funding from PwC and Harvard University.

Narration by Olivia Kang, featuring Professor Mahzarin Banaji (Harvard University) and Brian Nosek (University of Virginia)

Sound Editing & Mixing by Evan Younger

Clip from Star Trek episode “Mirror, Mirror” (airdate 6 Oct 1967) copyright CBS

Music by Miracles of Modern Science

Artwork by Olivia Kang