Hockenbury Discovering Psychology 5th txtbk

304 CHAPTER 7 Thinking, Language, and Intelligence“I don’t have to be smart, because somedayI’ll just hire lots of smart people to workfor me.”What about practical intelligence? As shown in the Prologue, dealing with the socialand academic environment of high school is not easy for Tom. However, manypeople with Asperger’s find a compatible niche in workplaces in which their abilityto focus their attention on a particular technical problem, their preoccupation withdetails, and other unusual abilities are highly valued, such as in computer programmingor engineering firms. In such an environment, their lack of social skills mightactually be advantageous (Mayor, 2008). As Sternberg’s theory would predict, behaviorsthat are deemed “intelligent” in one environment—such as a software developmentfirm—might well be maladaptive in another environment—like a highschool cafeteria (Sternberg, 2008).The exact nature of intelligence will no doubt be debated for some time. However,the intensity of this debate pales in comparison with the next issue we consider:the origins of intelligence.The Roles of Genetics and Environmentin Determining IntelligenceKey Theme• Both genes and environment contribute to intelligence, but the relationshipis complex.Key Questions• How are twin studies used to measure genetic and environmental influenceson intelligence?• What is a heritability estimate, and why can’t it be used to explain differencesbetween groups?• What social and cultural factors affect performance on intelligence tests?The nature-versus-nurture debate isnow informed by current research onmolecular biology that moves thequestion from which factor is moreimportant to how and whenexpression of the human genome istriggered and maintained. The basicbehavior genetics issue has becomehow environment influences geneexpression.BERNARD BROWN (1999)Given that psychologists do not agree on the definition or nature of intelligence,it probably won’t surprise you to learn that psychologists also do not agree on theorigin of intelligence. On the surface, the debate comes down to this: Do we essentiallyinherit our intellectual potential from our parents, grandparents, and greatgrandparents?Or is our intellectual potential primarily determined by our environmentand upbringing?Virtually all psychologists agree that both heredity and environment are importantin determining intelligence level. Where psychologists disagree is in identifyinghow much of intelligence is determined by heredity, how much by environment.The implications of this debate have provoked some of the most heated argumentsin the history of psychology.Let’s start with some basic points about the relationship between genes and theenvironment. At one time, it was commonly believed that genes provided anunchanging, permanent blueprint for human potential and development. Today, the“genes as blueprint” metaphor has been replaced by a “genes as data bank”metaphor (Brown, 1999; Marcus, 2004). It’s now known that environmental factorsinfluence which of the many genes we inherit are actually switched on, or activated.As psychologist Bernard Brown (1999) writes, “Genes are not destiny. Thereare many places along the gene–behavior pathway where genetic expression can beregulated.”Take the example of height. You inherit a potential range for height, rather thanan absolute number of inches. Environmental factors influence how close you cometo realizing that genetic potential. If you are healthy and well-nourished, you mayreach the maximum of your genetic height potential. But if you are poorly nourishedand not healthy, you probably won’t.