The Frontal Cortex

Trust and Fraud

Here’s James Surowiecki on the surprising link between easy credit and rampant fraud, as epitomized by the Madoff ponzi scheme:



In recent years, there have been some extremely interesting experiments on the development and disintegration of trust. I’ve written about some of this work before:

[Read] Montague pioneered a technique known as hyper-scanning, allowing subjects in different fMRI machines to interact in real time. His experiment revolved around a simple economic game in which getting the maximum reward required the strangers to trust one another. However, if one of the players grew especially selfish, he or she could always steal from the pot and erase the tenuous bond of trust. By monitoring the players’ brains, Montague was able to predict whether or not someone would steal money several seconds before the theft actually occurred. The secret was a cortical area known as the caudate nucleus, which closely tracked the payouts from the other player. (The caudate is usually discussed in the context of addiction, since it plays a central role in modulating our expectation of pleasure.) Montague noticed that whenever the caudate exhibited reduced activity, trust tended to break down.

The key point is that trust is ultimately about the expectation of rewards. We like to think that trust is rooted in personal qualities, and that we trust people who are, well, more trustworthy. Alas, the social brain isn’t quite so lofty – we compute trust based on calculations of future reward and profit. This is why, as long as Madoff kept on generating those 12 percent returns, nobody (not even the SEC!) was interested in questioning his scheme. He was a liar and a cheat who seemed honest, simply because he made other people lots of money. (Of course, now we know where that money came from…) As Surowiecki notes, it wasn’t until those rewards disappeared that people began to suspect that something wasn’t right, even though it’s clear (at least in retrospect) that Madoff’s lies should have been uncovered long before.


  1. #1 Pierce R. Butler
    January 15, 2009

    So if brain techies can ever devise a way to read caudate nucleus activity remotely, we’ll be able to tell when the suckers are getting suspicious and cut out before they call the cops… (rubs hands with glee)

  2. #2 Cannonball Jones
    January 15, 2009

    I do love the fact that it was the negative effects of their own greed that exposed their schemes, seems very poetic. I’d like to think people would be more careful next time round but history suggests that we’re not great at learning from our mistakes…

  3. #3 OftenWrongTed
    January 15, 2009

    Perhaps the Madoff disaster is an example of ‘affinity fraud’, intentionally perpetrated upon professional people who had the initial inclination to garner trust in the eminent reputations of the other investors. People victimized by this guy typically set incredibly high demands upon themselves as scientists, artists, and authors, leaving little time for a financial due-diligence study. It is interesting to note that The Harvard Fund was not a victim of this scheme, although some of the victims are Harvard Alumni.

  4. #4 Joe
    January 19, 2009


    The fact that a study which was focused on learning which part of the brain is activated in matters of trust, which did so by using a game with reward involved, found that a certain part of the brain was activated when someone felt they would get a reward… does NOT mean that in social life we do not trust people because they actually are trustworthy.

    That is a leap of logic which bases its conclusion on only one piece of data, from which many other possible conclusions can be reached.

    Why decide that human beings are only out for themselves, based on these results, when a million other possible conclusions can be reached?

    The intent of the study should not dictate the meaning of the data which is found in the study. The idea that trust is based on future reward alone is not the absolute only possible conclusion from this data. So, one part of the brain was activated, in this study… that means nothing, whatsoever.

    There is a huge difference between the trust that is built up when you know someone intimately, and you know that they are a good person, and “trust” that is built up based on a game where you are trying to profit monetarily.

    To say that this study means that trust is only “expecting reward in the future”, is to take a very, very narrow view on trust on the whole.

    This study shows only that when you’re playing a game where you can get a reward, a certain part of your brain will activate in certain circumstances. The difference between that scenario, and a scenario where for instance you trust someone because they’ve loved you and taken care of you for 20 years, is entirely, entirely, entirely different.

  5. #5 Joe
    January 19, 2009

    Trust is based on knowing that someone is a decent person. Not on believing that you can get something out of them. Take a brighter view on humanity, you’ll feel the better for it, in 10 years.. otherwise it would be easy to end up being pretty cynical.

  6. #6 Matt Grist
    January 20, 2009

    Perhaps when thinking about trust in the corporate world we should consider the evolved parametrics of the social brain as it is studied in evolutionary psychology and anthropology? For more on this see
