Posted on April 7, 2011

The Evolution of Prejudice

Daisy Grewal, Scientific American, April 5, 2011


Yale graduate student Neha Mahajan, along with a team of psychologists, traveled to Cayo Santiago, an uninhabited island southeast of Puerto Rico also known as “Monkey Island,” in order to study the behavior of rhesus monkeys. Like humans, rhesus monkeys live in groups and form strong social bonds. The monkeys also tend to be wary of those they perceive as potentially threatening.


Mahajan and her team also devised a method for figuring out whether the monkeys harbor negative feelings towards outsiders. They created a monkey-friendly version of the Implicit Association Test (IAT). For humans, the IAT is a computer-based task that measures unconscious biases by determining how quickly we associate different words (e.g. “good” and “bad”) with specific groups (e.g. faces of either African-Americans or European-Americans). If a person is quicker to associate “bad” with African-American faces compared to European-American faces, this suggests that he or she harbors an implicit bias against African-Americans.

For the rhesus monkeys, the researchers paired the photos of insider andoutsider monkeys with either good things, such as fruits, or bad things, such as spiders. When an insider face was paired with fruit, or an outsider face was paired with a spider, the monkeys quickly lost interest. But when an insider face was paired with a spider, the monkeys looked longer at the photographs. Presumably, the monkeys found it confusing when something good was paired with something bad. This suggests that monkeys not only distinguish between insiders and outsiders, they associate insiders with good things and outsiders with bad things.

Overall, the results support an evolutionary basis for prejudice. Some researchers believe prejudice is unique to humans, since it seems to depend on complex thought processes. {snip} But the behavior of the rhesus monkeys implies that our basic tendency to see the world in terms of “us” and “them” has ancient origins.

Psychologist Catherine Cottrell at the University of Florida and her colleague Steven Neuberg at Arizona State University, argue that human prejudice evolved as a function of group living. Joining together in groups allowed humans to gain access to resources necessary for survival including food, water, and shelter. Groups also offered numerous advantages, such as making it easier to find a mate, care for children, and receive protection from others. However, group living also made us more wary of outsiders who could potentially harm the group by spreading disease, killing or hurting individuals, or stealing precious resources. To protect ourselves, we developed ways of identifying who belongs to our group and who doesn’t. Over time, this process of quickly evaluating others might have become so streamlined that it became unconscious.

Psychologists have long known that many of our prejudices operate automatically, without us even being aware of them. Most people, even those who care deeply about equality, show some level of prejudice towards other groups when tested using the IAT. Despite this overwhelming evidence that our brains are wired for bias, our society continues to think about prejudice as premeditated behavior. Our current laws against discrimination, as well as the majority of diversity training programs, assume that prejudice is overt and intentional. Rarely do we teach people about how automatic prejudices might taint their behavior towards others.

The fact that prejudice often occurs automatically doesn’t mean we can’t find ways of overcoming its negative effects. For example, there is evidence that when people are made aware of their automatic prejudices, they can self-correct. And when we are encouraged to take the perspective of an outsider, it reduces our automatic prejudice towards that person’s group.

Given that most of the difficult conflicts we face in the world today originate from clashes between social groups, it makes sense to devote time to understanding how to reduce our biases. {snip}

22 responses to “The Evolution of Prejudice”

  1. Southern Hoosier says:

    This story is quite a stretch. There is a difference between not trusting a stranger who is like you and not trusting someone that is different. I trust Blacks that I know a lot more than some White guy walking up to me that I don’t know. These are all rhesus monkeys they are talking about. The young males were accepted into the groups, once the other monkeys got to know them, not because they changed their color.

  2. Wayne Engle says:

    This is so typical of scientists of a liberal persuasion. They discover through careful testing that prejudice, so-called, exists even in monkeys (and, I suspect, in other animals as well). They find it is part of — well, in our case, human nature — as a protective device against “The Stranger at Our Gate,” to use a phrase of Rudyard Kipling’s.

    They also find that “group solidarity,” if one wants to use that term, is encoded into our genes; that it is a human instinct which has evolved over many thousands of years.

    Then, having determined all that, they start trying to think of ways that we might be able to short-circuit all that genetic coding, because those who are More Noble Than Ourselves have decided that it is “racist” and in conflict with the struggle for “equality.”

    I have just two things to say about that. I have a friend who, if someone calls him a “racist,” says, “Thanks for the compliment.” And as for myself, I would add, “What’s so all-fired great about equality, anyhow?”

  3. Lucas says:

    Who pays for a group of psychologists to go to Monkey Island in Puerto Rico? It really is too bad that academia has abandoned common-sense.

    Through millions of years of evolution, mammals with higher intelligence have learned to avoid death and danger by automatically avoiding certain apparent and implied dangers or by simply and instinctively fearing them. Instinct is an unlearned response to stimuli handed down from mother to child in the womb via DNA. Ever notice a male puppy, having never seen another male dog do it and yet instinctively lifts his leg to mark his territory or walks in circles before laying down to sleep? How about burying bones or barking at strangers? Where does that behavior come from?

    We instinctively avoid those who are strange or different as a survival mechanism. This trait has served us well until recently when political correctness has come into vogue.

    We fear strangers for a reason. The more different or strange a person is, the more we should fear them until proven otherwise.

    Human beings should be allowed to embrace the feelings, instincts and emotions that have served them well for hundreds of thousands of years. They should be allowed to associate or avoid whomever they chose without worrying about being called names by the PC police.

    We don’t need a bunch of overpaid politically correct educators gazing at monkeys to create propaganda and tell us that our instincts are wrong or negative.

    Our biological instincts have served us well thus far. The propaganda hasn’t.

  4. Anonymous says:

    This article shows that even the “hard” sciences have become opportunities for liberal propaganda. Years ago, I read about a study that showed that plants can recognize there genetic equals, and react differently toward them. So, there is nothing seminal in Mahajan’s research. It’s called in-group versus out-group behavior.

    Also, consider the liberal bias of the title of her article,”The Evolution of Prejudice”; instead of a neutral title, such as “Differenial Behaviour in Rhesus Monkeys”.

  5. Browser says:

    This article shows that even the “hard” sciences have become opportunities for liberal propaganda.

    Also, consider the liberal bias of the title of her article,”The Evolution of Prejudice”; instead of a neutral title, such as “Differenial Behaviour in Rhesus Monkeys”.


    Yes, such studies as these always approach the subject from theobjectevity standpoiht that they are are investigating an illness, a social pathology, which needs to be cured. They are looking for a way to “cure” it.

    There is no objectivity at all. Their minds are already made up. But what could we expect from a reseacher named Neha Mahajan?

  6. Anonymous says:

    Fine, it makes sense to me that monkeys would be prejudiced. But I’m not prejudiced. Most of us here aren’t prejudiced. We have informed opinions, based on facts, not primal instincts.

    This is a key truth that the general public is increasingly discovering.

  7. Anonymous says:

    The simple truth is that white people are for various reasons POSITIVELY disposed towards other races, not negatively.

    as a rule, it is FAMILIARITY which breeds distrust.

    I’ve seen this happening in Europe over the past 15 years:

    after welcoming tens of millions of Muslim immigrants on the bizarre assumption that they are “just like us,” Europeans have now turned sour upon realizing that Muslims are in fact profoundly different from us.

    After welcoming your new neighbor with open arms and introducing yourself with a basket of cookies and arranging play dates with their kids, you go sour on them after you see them swearing at their kids, getting drunk before breakfast, throwing their trash in your backyard, driving 60 miles an hour through a play street, and playing loud music at 3 AM.

    When it comes to guilt ridden white people, and their fetish for groveling before brown people, is only the most consistently atrocious behavior that is capable of turning us against people who are different.

    The relationship between blacks and whites in the US has evolved into something incredibly sick and perverted – like a marriage between an sadistic, explicative sociopath and a guilt ridden neurotic masochist.

    Guess which is which.

    Staring at monkeys won’t help us to understand why white people are so self-destructive.

  8. Doug says:

    Surely the main point of the in group preference is that the individual is likely to share more genes with the in group members.

  9. dutch henry brown says:

    why not try this experiment? have two whites walk the streets of camden nj after the sun goes down and see how the social groups that inhabit that area react to the two outsiders. i wonder if the inhabitants will be able to correct their prejudices?

  10. sbuffalonative says:

    Here is what you need to know about this experiment:

    The fact that prejudice often occurs automatically doesn’t mean we can’t find ways of overcoming its negative effects.

    First the researchers know they have to prove the obvious (which they already know), that animals prefer their own.

    The purpose is not to prove what we instinctively know. The REAL purpose is to find ways to breakdown our innate distrust and dislike of others.

    These people don’t want to understand nature, they want to make nature to conform to their morally superior, politically correct ideology.

  11. Anonymous says:

    Possibly one of the clearest delineations of the inborn “us/them” dichotomy is our deeply programmed “prejudice” in favor of our own children vis a vis the children of others. We are not “racists” for being so devoted to our own children that in a severe “lifeboat” choice situation, we would be willing to throw overboard other children so that our own could survive. Reality is the foundation for any enduring m o r a l i t y.

  12. Anonymous says:

    High time they came along to change that “bad evolution of prejudice” and get them monkeys to love all and sundry.

    It happens that goats, sheep and cows will accept an orphan and raise it. Most of the time however, they knock somebody else’s offspring for a loop. Everything takes care of their own first, then comes nothing and then comes you. And you have to prove yourself. Except modern white people have been so brainwashed and conditioned, they kick their own in the teeth and slobber over those that hate them.

  13. Anonymous says:

    Wayne Engle wrote:

    This is so typical of scientists of a liberal persuasion. They discover through careful testing that prejudice, so-called, exists even in monkeys (and, I suspect, in other animals as well).


    I recall reading that mice who have been separated from their pack for a while will be attacked by the others when returned to the pack … because they have lost the smell of the pack and they are perceived as strangers.

  14. SavetheWest says:

    I have to say that people are always going to gravitate to common ideas, communities, social circles, etc… I think that Whites/Westerners have been indoctrinated for so long that they are no longer aware of their surroundings. That is why so many have fallen victim to crime, not only by other Whites who are street-savy, but minorities to see easy marks. It’s sad but true. I do think that we will wake up (get your conceal carry). We will when our numbers are at critical levels.

  15. Anonymous says:

    You might be a Racist if:

    You are White.

    Your parents are White.

    You are White and married another White.

    You are White and have White children.

    Your White children have White teachers.

    You are White and have a White boss.

    You are White and have a White preacher.

    You are White and have a White doctor.

    You are White and have a White lawyer.

    You are White and didn’t apply to a Historically Black College or University.

    Your White children are not looking forward to attending black Spellman or black Morehouse.

    You are White and not seriously considering moving from your White neighborhood and into a “community of color” neighborhood that reflects the vibrant culture of multicultural communities.

    You are White and don’t feel the urgent need to export your diversity into non diverse black and brown neighborhoods.

    You are White and haven’t put a moratorium on hiring more Whites until your business “truly reflects the growing and enriching diversity of the community it serves”.

    You are White and lock your car doors when you see a black on the sidewalk.

    You are White and tell your children that they aren’t allowed to talk to strangers, unless the stranger is a black.

    You are White and aren’t “doing more to atone for the sins of segregation by holding yourself accountable to people of color for your unearned White privileges”.

    You are White and don’t have framed pictures of Rosa Parks and MLK on the wall above your family dining room.

    You are White and don’t “confess your burden of White privilege”.

    You are White and are not actively supporting the campaign to change the Constitution so that black Obama can have his much deserved and transformative third term.

    You are White and did not report another White to the DOJ hate crimes unit when he said “n****r”.

    You are White.

  16. Conrad says:

    I don’t know if I can put much faith in this test but we know for certain that Chimpanzees patrol their territories to drive off other Chimps. In short the article shows us that “prejudice” is normal and needed to survive.

  17. Marc B says:

    Anybody that has ever entered an area with a majority population of another race/ethnicity could tell you this if they haven’t already been brainwashed by post-modern liberalism. It’s nice to at least see university level research dispelling the mythology that they are indoctrinating the student body with.

  18. Anonymous says:

    It’s a little disturbing to see people who should be educated in how the mind works, trying desperately to find a biological basis for something that doesn’t exist in reality. They only think it does because they’ve been brainwashed… people who obviously know a lot about how the mind works and how to use that knowledge to maintain near Orwellian levels of control on our society.

    The guys who are supposed to study stuff like that? Probably spent ten to fifteen years studying the mind from various angles?

    Completely clueless.

    By the way, this is one of the key topics that should be at the very top of any agenda of white resistance. Whites need to study mind control (information is not as hard to obtain as you think). Even basic knowledge, opens up a fascinating doorway to observe what they are doing in all media. Almost nothing is as it seems when you see the real intent behind their behavior.

    Any real white resistance to what is being done to us, starts here. You simply cannot place the truth (for example, the truth of racist hate crime by blacks against whites) and expect the person to do other than dismiss it, unless you can counter the brainwashing they’ve been subjected to.

    That’s the bad news. The good news is, imagine if you could? And imagine if a wave of anti-brainwashing were to suddenly spread to all whites everywhere. A movement where all people put their TV’s out with the trash (or can simply see what they are being subjected to and get good and angry about it).

    It’s their Achilles heel. The only real power they have.

    By the way, if you want a good primer, get the books by Jeffry Grupp. Start with Corporatism. Grupp is one of the hard core conspiracy theorist crowd. However, unlike most of them, he forms an effective basis of seeing how the world actually is, as opposed to how they want you to assume it is. Many of the so called “conspiracies” are actually proven fact. You’ll get a good selection of those in his book as examples of how to tell the difference.

    The point of the book is just because there is consensus (usually manufactured consensus) on something, doesn’t make it true. But also, something being radically different from what is accepted, doesn’t make it true (or false) either. What makes something true is careful observation of the facts, a skeptical mind, that constantly questions what we are being told.

  19. John Engelman says:

    1 — Southern Hoosier wrote at 6:30 PM on April 7:

    This story is quite a stretch. There is a difference between not trusting a stranger who is like you and not trusting someone that is different. I trust Blacks that I know a lot more than some White guy walking up to me that I don’t know.


    I’m glad someone else said it first. I have no illusions about blacks as a race, but I like the ones I know.

  20. Browser says:

    The premise of all articles such as this (which is automatically accepted without question) is that “prejudice” is an illness, and they are looking for a way to cure it.

    By extension of this assumption, people who are “prejudiced” are mentally ill and need to be treated for their sickness.

    No way do such, uh, “scientists” ever take the neutral (much more scientific) position that maybe – just maybe – prejudice is normal and serves a natural purpose.

    Why is it that prejudice is found among ALL peoples, cultures, and tribes around the world? Are they ALL mentally ill?

    Why did the Sioux hate the Chipppawa? Why did the Hurons hate the Iroquois? Why did the Slovaks hate the Hungarians, the Romans hate the Carthaginians, etc? Wherever you have different peoples contending for the same land and resources you are going to have ugliness.

    It seems to me that Miss Neha Mahajan, instead of investigating the pathologies of Americans, might do better to investigate the many ethnic and religious hatreds of her home country, India (?). That is a place much richer in ancient hatreds and discord than we could possibly claim to be.

  21. Anonymous says:

    Xenophobia is a normal, healthy and adaptive response to foreigners whereas xenomania (loving foreigners more than your own people) is abnormal, pathological and maladaptive response to foreigners.

  22. Anonymous says:

    Those researchers should try entering a few of the new no go areas in France and report back on their experiences.