engleski

Behavioral genetics and personality: Implications for consumer personality and behavior research

The issue of the nature and nurture is one of the oldest questions in the behavioral sciences. The modern form of this fundamental question is represented in the field of behavioral genetics. Behavioral genetics includes both quantitative and molecular genetic approaches to investigate genetic and environmental influences on behavior. Behavioral genetics as a discipline has two branches: quantitative and molecular behavioral genetics. Historically, these two approaches were developed in a different times, and they use different methodology. Behavioral genetics has studied personality almost exclusively in terms of psychological trait theory. The reason for that is the nature of the concepts that are central in these theories. However, several competing trait models and measures of personality do exist. Behavioral genetic studies usually use Eysenck's PEN model, Costa's & McCrae's Five-factor model or Tellegen Three-factor model. On the other hand, Cloninger's psychobiological model was particularly useful in the molecular genetic studies of personality. Results of these studies converge on two conclusions that are now generally accepted in the field of personality. First, most of the personality traits are moderately heritable. Monozygotic twin correlations are greater than dizygotic twin correlations. This finding is consistent across different populations as well as across different age of the participants or the instruments which is used for measurement of personality. Second, there is no replicated evidence about differential heritability of personality traits. Behavioral genetics is a research field that studies the etiology of individual differences by relating these individual differences to the genetic and environmental differences between individuals. Is it useful for the more applied disciplines, such is Consumer personality or Consumer behavior? Have behavioral genetics findings any implications for those fields? I would like to give a comment on that and point up the four issues. First, some concepts which are used in the consumer personality and behavior are the individual differences concepts. Second, the potential of the multivariate genetic analysis to investigate the sources of covariation between two or more variables. Third, the key concept in the behavioral genetic studies is the heritybility. Has heritability any significance in the real world? One of the first lessons that student of behavioral genetics has to learn is that heritability estimates do not tell us anything about how hard or easy it will be to change a given trait. High heritability does not mean that trait is impossible to change, and low heritability does not mean that trait would be easy to change. The classic example in the behavioral genetic literature is phenyllketonuria, a disease that is genetic in the straightforward sense. Phenyllketonuria is a single-gene defect that, if uncured, resulted in severe mental retardation. The cause of this mental retardation is the inability to break down the phenylalanin, which led to its accumulation in the blood. However, the effective cure of this genetically caused disease is environmental - a strict diet low in phenylalanin during the developing year. In spite of fact that heritability is not causally related to the changeability of behavior, we can ask ourselves can heritability predict anything relevant. The focus in behavioral genetics is on naturally occurring sources of variance. Thus, for each specific domain of behavior within each population we can investigate the predictive validity of heritability. The good example is series of studies made by Tesser (1993 ; 1994 ; 1996 ; 1998). In the first study Tesser shown that attitudes higher in heritability are reported more quickly, and are more resistant to change than attitudes low in heritability. He used heritability estimates for 20 different attitudes from the earlier twin study conducted by Martin et al. (1986). After that, he estimated the response strengths of these attitudes and found that more heritable attitudes showed more response strength. We should not jump to the false conclusion that this is directly applicable in the prediction of changeability of any attitude, no matter of what treatment is applied for each specific attitude. However, this study shows that concept of heritability can be useful and that research of the correlates of heritability in each particualar domain of behavior is needed.

behavior genetics; consumer personality; consumer behavior

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