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The infant mind’s not-quite “blank slate”

Oct. 30, 2006
Special to World Science  

New find­ings may have clar­i­fied an old de­bate over wheth­er our men­tal abil­i­ties are main­ly born with us, or de­vel­oped through ex­pe­ri­ence, re­search­ers say.

An emerg­ing an­swer, a study sug­gests, is that we in­her­it­ed some bas­ic ten­den­cies from our ape-like an­ces­tors, but dif­fer­ent hu­man cul­tures can ei­ther re­fine or over­ride those.

An orangutan, one of five ex­tant spe­cies of Great Apes, de­fined as hu­mans and their clo­s­est re­la­tives. All five spe­cies were tested in a new stu­dy prob­ing the boun­d­a­ries be­t­ween in­nate and cu­ltur­al pre­fer­ences. (Cour­te­sy Ka­trin Riedl)


The find­ings are the lat­est page in a de­bate that tra­ces roots to an­cient Greece. Phi­lo­so­phers on one side have ar­gued that the new­born mind is a “blank slate” that ac­quires dis­tinc­tive prop­er­ties on­ly through life ex­pe­ri­ence.

Most sci­en­t­ists by now ac­cept that he­red­i­ty and en­vi­ron­ment both help shape shape the mind, but just what each con­tri­butes re­mains very fog­gy.

To sim­pli­fy the prob­lem, re­search­ers at the Max Planck In­s­ti­tute for Psy­cho­lin­guis­t­ics in The Ne­th­er­lands, who con­duc­ted the new stu­dy, fo­cused on just one men­tal skill that they called cen­tral to cog­ni­tion: spa­tial mem­o­ry.

They stud­ied the per­for­mance and stra­te­gies of great apes, hu­man chil­dren and hu­man adults of dif­fer­ent cul­tures on spa­tial tests. 

The re­search­ers found that hu­man skills and stra­te­gies var­ied by cul­ture at least from eight years of age on­ward. But there was just one strat­e­gy com­mon to hu­man four-year-olds and apes.

That sug­gests the great apes and hu­mans in­her­it si­m­i­lar pref­er­ences, but cul­ture molds those of hu­mans to dif­fer­ent per­spec­tives and strate­gies, they added. The find­ings, they ar­gued, add to grow­ing ev­i­dence that cog­ni­tive stu­d­ies us­ing West­ern sub­jects may not rep­re­sent the full range of hu­man abil­i­ties.

The re­search team iden­ti­fied two strate­gies as com­mon for spa­tial prob­lems among the groups they stud­ied. 

One strategy is self-cen­tered: lo­ca­tions are de­scribed with ref­er­ence to one’s self, usu­al­ly to the left, right, front or back. The oth­er is “en­vi­ron­ment”-centered: ob­jects are de­scribed by their po­si­tion with re­spect to each oth­er. An ex­am­ple is “the ball is in front of the house.”

Apes and young hu­man chil­dren pre­fer the en­vi­ron­ment-centered strat­e­gy; but adult pref­er­ences vary by cul­ture, the re­search­ers wrote in the stu­dy, pub­lished in this week’s ear­ly on­line edi­tion of the journal Pro­ceed­ings of the Na­tio­n­al Aca­de­my of Sci­ences.

For in­stance, the sci­en­tists ob­served, en­vi­ron­ment-centered pro­cess­ing is usu­al for mem­bers of a hunter-gatherer com­mu­ni­ty in Na­mib­i­a called ≠Akhoe Hai║om (the unu­su­al sym­bols stand for click­ing sounds.) Self-cen­tered pro­cess­ing is typ­i­cal for Eu­ro­peans.

The emerg­ing pic­ture, the re­search­ers wrote, is that there ex­ists an “in­her­it­ed bi­as to­ward the al­lo­cen­tric,” or en­vi­ron­ment-centered, cod­ing, but this “can be over­rid­den by cul­tur­al pref­er­ences.”

How­ev­er, “this over­ride is not a rare or typ­i­cally Eu­ro­pe­an phe­nomenon,” they added: it al­so oc­curs in both in­dus­tri­al and tra­di­tion­al cul­tures world­wide, in­clud­ing some tribes­men who live just a few hun­dred kilo­me­ters from the ≠Akhoe Hai║om ar­ea.

There al­so ex­ists a third place-cod­ing sys­tem, the re­search­ers not­ed, called “ab­so­lute.” In this, places are de­scribed in terms of North, East, South or West, or equiv­a­lents. 

While this technique is occasional for West­ern­ers, speak­ers of Gu­ugu Yi­mi­thirr in Aus­tral­ia know on­ly it, ac­cord­ing to the stu­dy’s lead auth­or, Dan­iel Haun. “A Gu­ugu Yimithirr speak­er would say ‘There’s an ant on your south leg,’” he and other col­leagues wrote in a pre­vi­ous pa­per in the March 2004 is­sue of the jour­nal Trends in Cog­ni­tive Sci­ences.

The “over­ride” the­o­ry, Haun and col­leagues wrote in the new stu­dy, sug­gests self-cen­tered pro­cess­ing should be harder to learn than en­vi­ron­ment-centered. Past re­search sug­gests this is in­deed the case, they added.


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New findings may have clarified an old debate over whether our mental abilities are mainly born with us, or developed through experience, researchers say. The emerging answer, a new study suggests, is that we inherited some basic tendencies from our ape-like ancestors, but different human cultures can either refine or override those tendencies. The findings are the latest volley in a debate that traces roots back to ancient Greece, with philosophers on one side arguing that the newborn mind is a “blank slate” that takes on distinctive properties only as the infant gains experience. Most scientists by now accept that heredity and environment both help shape shape the mind, but just what each contributes remains very foggy. To simplify the problem, researchers at the the Max Planck Institute for Psycholinguistics in The Netherlands, who conducted the new study, focused on just one mental skill that they described as central to human cognition: spatial memory. They studied the performance and strategies of great apes, human children and human adults of different cultures on tests of spatial relationship skills. The researchers found that human skills and strategies on these tests varied by culture at least from 8 years of age onward. But there was just one strategy common to human four-year-olds, along with apes of many species. That suggests the great apes and humans inherit similar preferences, but culture molds those of humans to different perspectives and strategies, they added. The findings, they argued, add to growing evidence that cognitive studies using Western subjects may not represent the full range of human abilities. The research team identified two thinking strategies as common for spatial problems among the groups they studied. One is self-centered: locations are described with reference to one’s self: usually to the left, right, front or back. The other is “environment”-centered: objects are described by their position with respect to each other. An example would be “the ball is in front of the house.” Apes and young human children prefer the environment-centered strategy, also called allocentric; but adults preferences vary by culture, the researchers wrote in the study, published in this week’s early online edition of pnas. For instance, the scientists observed, environment-centered processing is usual for members of a hunter-gatherer community in Namibia called ≠Akhoe Hai║om (the unusual symbols stand for clicking sounds.) Self-centered processing is typical for Europeans. The emerging picture, the researchers wrote, is that there exists an “inherited bias toward the allocentric,” or environment-centered, coding, but this “can be overridden by cultural preferences.” However, “this override is not a rare or typically European phenomenon,” they added: it also occurs in both industrial and traditional cultures worldwide, including some tribesmen who live just a few hundred kilometers from the ≠Akhoe Hai║om area. There also exists a third place-coding system, the researchers noted, called “absolute.” In this, places are described in terms of North, East, South or West, or equivalents. While Westerners use this strategy sometimes, speakers of Guugu Yimithirr in Australia know only it: “a Guugu Yimithirr speaker would say ‘There’s an ant on your south leg,’” wrote Daniel Haun, lead author of the new study, and colleagues in a previous study in the March 2004 issue of the journal Trends in Cognitive Sciences. The “override” theory, Haun and colleagues wrote in the new study, suggests self-centered processing should be harder to learn than environment-centered. Past research suggests this is indeed the case, they added.