The greatest sin–and virtue–of human memory

August 11, 2006 | By | 7 Replies More

The human brain has a remarkable ability to categorize data. We use heuristics, or mental “rules of thumb”, to make sense of the world around is with efficiency, and usually, accuracy. That vital ability to generalize has protected us from harm since the beginning of our species, and it still aids us immensely in processing and storing information.

But the human tendency to generalize also gets us in a lot of trouble. The brain’s predisposition to throw sensory and contextual data into categories takes much of the blame for forms of human illogic such as stereotyping, prejudice, and jumping to conclusions.

Disillusioned with the failings of our logical process, we may feel tempted to shirk the instinct to generalize all together. At first blush, it sounds like a fantastic (if impossible) way to cure the world of much its ignorance and needless hate. If we could remove the part of the brain that draws quick conclusions automatically, where would that leave us as a species?

Well, it would make us autistic.

Psychologists associate autism with poor social skills, lacking communication ability, and a stubbornly structured and highly literal way of information processing. According to Harvard University Professor of Psychology Daniel Schacter in his book The Seven Sins of Memory, Autistics lack real-world critical thinking skills because they look at everything in an individualized, literal way. This explains in part why autistics tend to have astounding rote memorization, yet lack any grasp of context.

Without the ability to generalize, we would all function like the movie Rainman’s real-life inspiration, a man named Raymond Babbit, who could calculate vastly complex mathematical problems but couldn’t understand the basic concept of buying and selling goods. If we couldn’t categorize numbers as “quantities” “weights” “heights” or “prices”, the cost of an item would seem like a foreign, nonsense concept, and no different from any other number.

Our ability to generalize also plays a key role in the function of memory. As much as it may bother us when we fail to remember a specific detail- what song we heard at a wedding reception, where we left the car keys- our tendency to recall only the “gist” of things makes memories more manageable. As Schacter writes:

what would be the consequences of retaining the myriad of contextual details that define our numerous daily experiences? We seldom need to remember all of the precise sensory and contextual details of every experience.”

Imagine if your brain didn’t categorize sensory data as “important” or “not important”, and instead took a perfect mental snapshot. Imagine that you could remember every song, every person, and every weather condition you ever encountered. Schacter postulates that this would make summoning a specific memory even more maddening.

And what of the generalizations that lead to biases and stereotypes? Unlike with memory, such generalizations have regrettable effects such as racism, yet the common tendency to associate men with aggression, blacks with poverty or crime, and artists with temperamental attitudes (to name a few) comes from a justifiable adaptation. Schacter explains that we use stereotypes as

energy-saving devices that simplify the task of comprehending our social world. Because it may require considerable cognitive effort to size up every new person we meet as a unique individual, we often find it easier to fall back on stereotypical generalizations from various sources, including discussion with other people, printed and electronic media, and firsthand experience.”

Occasionally one hears the claim that “all stereotypes have their roots in truth”. Despite the complexity of the issues involved, black men do have the highest rate of arrest in the US, for example. Unfortunately, our brains don’t take the time to consider the difference between causation and correlation when analyzing a stranger in the dark as a threat. For that reason, even the mostly nonprejudiced have a much higher rate of fleeing from a black stranger in the dark than from a white stranger, according to a study by Professors Mahzarin and Banaji at Yale University.Stereotypes seem endlessly cruel, but consider this practical example of the brain’s generalizations at work: parenting magazines recommend that parents instruct their children to seek out women to help them in the event that they become lost, because women have a much higher likelihood of committing to helping (and of not having a history as a criminal or sexual predator). In the contemporary world, our tendency to generalize without a thought often harms us, but it comes from a sensible natural root. Even if we wanted to sever the ability, it would leave us in a worse predicament.


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Category: Bigotry, Psychology Cognition, Reading - Books and Magazines, Recommended Reading/Films/Sites

About the Author ()

Erika is a PhD student in Social Psychology living in Chicago. Here on DI she most often writes about current events, psychology, skepticism, media and internet culture.

Comments (7)

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  1. Ricky Koppel says:

    I think that many stereotypes are self-fulfilling. This also goes for gender roles and stereotypes.

    Because women are, historically speaking, usually the housekeeper of a couple, I think it serves to establish a precedent in which future women will have an example to follow, thereby keeping the number of female housekeepers at a stable ratio.

    There are endless examples, so I won't bother mentioning them. I believe that the manner in which one is expected to act reinforces the manner in which they will act.

    I base this reasoning on the matter of influence. If, when deciding which action to take, we have no influence either way, we reach a point of indecision. However, if in this same case we have a precedent to follow, our decision will be influenced towards that choice, because we have little motivation to do the opposite.

  2. Heather says:

    You are so right (that's why you wrote this, of course). Folks try to fix the issue of racism and stereotypes with quick fixes not realizing that it is a survival mechanism for the human species. Imagine back in the stone ages, if you saw anyone who didn't look like your family you rightfully better get your fightin boots on, not only to protect your life, but to protect your resources and "childbearers"! This progressed into different colors of skin and so on.

    Not your main topic, but a note on Autism. I have a theory that autism and now autism's little brother Asperger's Syndrome are major successes in human evolution. I read that cases of Asperger's Syndrome in California (mostyly the Silicon Valley area) have tripled in the past decade.

    Most people with Asperger's Syndrome exibit very high intelligence with limited social skills, but not to the extent of Autism. The catch is that they are smart enough and possess enough theory of mind to gradually change these inhibiting factors in their lives. I know it sounds bad to glorify such debilitating disorders, but I believe, in time, these disorders will lead to the perfect human being.

  3. John says:

    This was interesting Erika. It reminded me of a very easy read that I finished recently; the curious incident of the dog in the night-time by Mark Haddon. It is a quick book and as mentioned easy to read, but very interesting in its portrayal of an autistic boy.

  4. Erika Price says:

    I absolutely agree with you about stereotypes, Ricky. We even refer to sexual stereotypes as gender "roles", so deeply do we expect the sexes to follow them. Yet as with the unfortunate racial stereotypes, they have a basis (though this time a natural one): women even have neural wiring better suited to the "gathering" half of the hunter-gatherer equation. Schacter writes in the same book that women have better spatial memory, which makes it easier to find a hidden store of food or shelter, for example, and men have better spatial navigation skills, which would help going out "on the hunt".

    But stereotypes also contribute to racial behaviors. When poor blacks see countless images of black criminals on the nightly news, when they hear the conventional wisdom that says they will all go to prison, and when the majority of hip-hop icons talk about getting shot (50 cent) or selling kilos of coke (Jay Z), it sends a message that they have no choice but crime, drugs, and poverty. That definitely makes the problem self-precipitating.

    Heather, John: I've heard of psychologists suspecting that Bill Gates has a mild form of autism, along with many of his peers. I've also heard computers called a tool "made by autistics, for autistics" several times.

  5. Erich Vieth says:

    There is no doubt that humans must cull down their sensory experiences in order to make use of them. As Erika points out, working with our sensory experience without categorization is not an option. We simply don’t have the cognitive capacity to do that.

    George Miller pointed this lack of working memory capacity in the 1950’s. He began his article by writing that he was “haunted” by a number. The number by which Miller was haunted is seven, which “applies to one-dimensional judgments.” Essentially, that number exposed severe limitations of working memory. “[T]he span of absolute judgment and the span of immediate memory impose severe limitations on the amount of information that we are able to receive, process and remember.” [See “The Magical Number Seven, Plus or Minus Two: Some Limits on our Capacity for Processing Information,” The Psychological Review, Vol. 63, No. 2 (March, 1956).] According to Miller, we can “break (or at least stretch) this informational bottleneck” by “organizing the stimulus input simultaneously into several dimensions and successively into a sequence of chunks.” [Id.,pp 87 & 95]. Though many researchers have further explored and re-conceptualized Miller’s number, no one doubts that humans must constantly struggle against meager attentional capacities. We are simply not capable of simultaneously thinking about everything we know.

    In 1999, I had the opportunity to hear a lecture given by a highly accomplished Professor of Neurobiology, David Van Essen. ["Translating the neural code: neurons as detectives, not detectors," Intentionality and the Natural Mind Workshop, Washington University March 19, 1999]. Van Essen’s work focuses on computational approaches to studying information processing in the nervous system, especially in the primate visual system. During his lecture, Van Essen quantified the manner in which the human mind must drastically simplify sensory information. He termed this the “informational pyramid”:

    1010 bits/second of information is the capacity of retina

    107 bits/second of information is the capacity of optic nerve

    104 bits/second of information is the capacity of attention

    And only 10 bits/second of information is the capacity of long term memory

    The research is clear then (this is made clear by many researchers, including Daniel Schacter, who is cited in Erika’s post) that humans must conceptually simplify their worlds in order to act (and thus survive). Even if we were able to hang on to all the individual details of our lives (we can’t), we would drown in them. As Daniel Schacter has pointing out (see Searching for Memory, Chapters 1-4), memories are not like photos in an album; we reconstruct them like we reconstruct dinosaurs from bone fragments.

    So where does that leave us? We absolutely must simplify the world in order to work with it. We also do this by categorizing our world. Sometimes we categorize things consciously. We might draw up a list of “types of things that Aunt Sally might like to receive for her birthday.” Quite often, though, we don’t consciously create our categories. They unfold, in connectionist fashion through a sort of “learned partitioning of neuronal activation spaces.” Further, we often create our categories “on the fly.” I highly recommend two extremely well written books on these ideas: Paul Churchland’s The Engine of Reason, the Seat of the Soul (1995) and Larry Barsalou’s Cognitive Psychology: An Overview for Cognitive Scientists (1992).

    We also apply emotional weights to our memories in order to quickly make use of them.

    I’m sorry that this comment is dragging on, but I believe that Erika’s topic is critically important. I’ll try to wind this up. I entirely agree that we categorize and that we must categorize and that we often categorize in pernicious ways.

    But just be because we must categorize doesn’t mean that we have absolutely no control over how we categorize. Those of us who are self-critical periodically examine the way we conceptualize. Those of us who are critical thinkers thus periodically do some conscious cognitive housekeeping. When we do this housekeeping, we sometimes discover that we are harboring a category that requires some retooling. Those who don’t do this self-examination tend to be less, shall I say, intellectually agile. It is those who allow sloppy categories to thrive (like weeds in their mental gardens) who tend to unreflectively act on horribly unfair racial and ethnic stereotypes. None of us can prevent all of those misbegotten categories from germinating, but all of us can do periodic cognitive gardening. If we pull out those weeds out at the roots and stay conscious of human tendencies to develop inaccurate categories, we, ourselves won’t sprout into bigots.

    In sum, we must categorize and we often subconsciously categorize badly, but those of us who are self-critical protect ourselves from acting on such over-generalizations. Yes, we must categorize but there are some things we can do so that we don’t act on sloppy and pernicious categories:

    I. Take the time to notice exceptions to our stereotypes. And notice how highly-bigoted people constantly fail to do this (do you ever hear religious fundamentals acknowledging redeeming social value of gays?). Noticing the exceptions (often there are many more exceptions that non-exceptions) is a good way to tame the confirmation bias. See here for more on that powerful bias.

    II. Do mental hygiene periodically. Think of it like mental flossing. Challenge our own ways of thinking. Many of our dysfunctional categories were unconsciously developed and they desperately need to be challenged.

    III. Challenge our news media, which tends to unthinkingly perpetuate many ill-fitting socially pernicious categories. In failing to challenge these categories in the context of particular stories, they perpetuate damaging stereotypes on a mass scale.

  6. grumpypilgrim says:

    Further to the first paragraph of Heather's comment, which mostly anticipated my thoughts, not only would there seem to be an evolutionary basis for prejudice — stemming from the life-and-death decisions that our ancestors had to make when meeting strangers — but we might even say that prejudice is far more 'normal' than non-prejudice. For millions of years, our ancestors faced potentially deadly threats from neighboring tribes, so prejudice was undoubtedly a crucial survival mechanism. Indeed, until the past few centuries, most humans rarely traveled more than twenty miles from where they were born, so prejudice was a trait our species never really needed to challenge. Only very recently have people from totally different cultures been thrown together on a large scale and brought literally face-to-face with the objects of their stereotypes. Accordingly, while I would join those who condemn prejudice, part of me is suprised that we, as a species, have come as far as we have in defeating it.

  7. Toto says:

    Memory… hmmm I don't remember anything.

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