5 FACTIBILIDAD ECONÓMICA DEL PROYECTO
5.25 FLUJOS DE CAJA
Eating disorders, which include anorexia and bulimia nervosa, are a common psy chological illness characterized by exacerbated worry about food, body shape, and weight, and related physical symptoms. More than any other mental illness, eating disorders are related to cultural, economic, and social factors, being much more common in Western industrialized countries than others. This is probably due to the current Western stereotype of beauty, which encourages women (and increasingly
PHOTO 4.7 There is increasing pressure on the fashion industry to change their ideals of female beauty, which encourage women to be extremely slim. This trend has coincided with the growing cases of eating disorders.
128 PERSONALITY AND INDIVIDUAL DIFFE'RE'NCE'')
also men) to stay thin -see Photo 4.7. Thus gender differences in eating disorders, a mental illness traditionally associated with women, have been reduced in the past 50
years or so.
Most anorexics start by dieting and can be objectively overweight initially, though their dieting efforts will persist after they have lost weight. Another common aspect is the experience of low self-esteem, for instance after being bullied at school or break ing up with a partner. In later phases of the illness, negative effects on relationships are typical, mostly driven by arguments about not eating. Thus psychotherapists have emphasized the importance of group/family therapy in treatment.
Like anxiety disorders, anorexia may be associated with the experience of anxiety, in particular when anorexic individuals fail to stop themselves from eating. Conversely, excessive concerns with food that successfully lead to a reduction of food intake will generate personal satisfaction and reduce anxiety. Anorexic individuals have often been described as quiet, unassertive, anxious, and sexually inexperienced. They also tend to be ambitious and achievement oriented, but have low self-esteem. In any case, this mere combination of personality attributes is not enough to predict illness.
Approximately 25 percent of individuals who suffer from anorexia will have long term difficulties, while the rest normally recover after one year of treatment (Hsu, 1990). Long-term symptoms may range from menstrual disorders in women to infer tility, starvation, and even suicide. It is also not uncommon for anorexic individuals to develop bulimia nervosa before fully recovering. Unlike anorexia, bulimia is not associated with actual weight loss and abnormal body weight, but bulimic individu als are significantly more likely than the average person to indulge in alcohol and drug consumption. Again, a combination of both psychotherapy and psychopharma cological drugs constitutes the best treatment for eating disorders (Agras et al., 1992).
Jen Hunter, the winner of the 2006 "Make Me a Supermodel" competition, sparked a huge debate about the fashion industry's ideals relat ing to body shape when she won the contest ahead of the skeletal Marianne Berglund. Jen repeatedly got told she was too fat and had to lose weight when she was a healthy size 12, whereas Marianne received continual com pliments about her great body despite her unhealthy BMI of 16. Soon thereafter, several big names in fashion stopped hiring size zero mod els after young Brazilian model Luise! Ramos died of self-starvation. This story highlights the
dangers of anorexia and the role of the media in shaping people's self-perceptions of body ideals.
The three major characteristics of anorexia nervosa are:
A serious and permanent concern about one's body shape, weight, and thinness.
An active pursuit and maintenance (through vomiting, dieting, or laxatives) of low body weight.
The absence of menstrual periods in females, indicating a disturbance of hor monal status.
PSYCHOPATHOLOGY 129
There has been much speculation about the etiology of eating disorders, particu larly in recent years. Unlike other disorders, there is little evidence for the vulnerabil ity hypothesis, though there is some proof of genetic influence, as the concordance rate for relatives is 10 percent, compared to 2 percent in the general population (Theander, 1970). Twin studies have found higher concordance rates for MZ than DZ twins (Sullivan, Bulik, & Kendler, 1998). On the other hand, from a feminist perspective (Bemis, 1978), eating disorders have been explained as an attempt to con form to certain stereotypes (usually portrayed by the media), while the family inter action hypothesis focuses on the role of dysfunctional families (Minuchin, Rosman, & Baker, 1978), notably intrusive or overinvolved parents.
4.8
CRITICISMS OF THE DIAGNOSTIC
APPROACH
Whereas the classification of syndromes into predefined diagnostic categories rep resents the dominant approach to mental illness in both psychiatry and psychopa thology, there have been several opposing views, most notably criticisms by the antipsychiatry movement (Szasz, 1960).
In his famous book Madness and Civilization, French philosopher Michel Foucault (1926-84) presented a comprehensive historical analysis highlighting the subjectiv
ity underlying the idea of mental illness and the fact that madness has always been associated with punishment. In the Middle Ages, lepers, the homeless, and "lunatics" were locked up or shipped away; in the l 7th century, they were imprisoned alongside criminals. Even with the introduction of treatment by the likes of Pine! and Tuke (see Section 4.3), says Foucault, the aim was to control rather than help those suffering from mental illness. Tuke's method was largely based on punishment and intimida tion of the mad until they were able to behave like most people, whereas Pinel's treat ment included freezing showers and straitjackets. Likewise, preestablished definitions of mental illness may merely reflect a political maneuver to punish individuals who do not "fit" into desirable social models, and diagnostic manuals such as the ICD or DSM would be designed to justify medical and social action against individuals who, albeit not responsible for any crimes, deviate from the norm.
Critics of the diagnostic approach also include experimental psychologists, such as Bentall (1990), who questioned the scientific soundness of the notion of schizophre nia (see also Boyle, 1990). Evidence for the occurrence of hallucinations and other psychotic symptoms in normal populations has long suggested that there may be a "continuum" between mental illness and normality (Bentall, 1990; Calton, 1880; Laroi et al., 2005). Indeed, Sarbin and Juhasz (1967, p. 353) argued:
Since the 1920s textbooks of general psychology have differentiated hallucinations from errors of perception by the simple expedient of locating them in separate chapters.
130 PERSONALITY AND INDIVIDUAL DIFFERENCES
Even when hallucinations are indicative of mental illness, they are not exclusive of schizophrenia but can often be found in affective psychoses such as mania (Taylor
& Abrams, 1975).
4.9
DIMENSIONAL VIEW OF
PSYCHOPATHOLOGY AND
PERSONALITY DISORDERS
In recent years, there has been an increasing shift toward a dimensional view of psy chopathology; that is, the idea that mental illnesses merely represent quantitative personality disorder
a persistent pattern of thinking, feeling, and behaving that deviates from cultural expecta- tions and impairs a person's educational, occupational, and inter personal functioning. Such disorders begin at a relatively early age, are stable over time, and are pervasive and inflexible.
(as opposed to qualitative) departures from normal behavior. This approach is epitomized by the notion of personality disorders,
defined as an "enduring pattern of inner experience and behavior that deviates from the expectations of the individual's culture, is per
vasive and inflexible, has an onset in adolescence or early adulthood, is stable over time, and leads to distress or impairment" (APA, 1994,
p. 629). Less severe than major psychoses and famously conceptual ized by Freud as "character neuroses," personality disorders affect an estimated 10-15 percent of the population (Zimmerman & Coryell,
1989). Although personality disorders may cause individuals to "feel at home in their own disordered condition" (O'Connor & Dyce,
2001, p. 1119), their disruptive nature is substantial and affects educa tional, occupational, and interpersonal functioning.
While personality disorders represent "either extreme or significant deviations from the way the average individual in a given culture perceives, thinks, and feels"
(WHO, 1993), they have been traditionally classified in categorical terms. Thus Axis 2
of the DSM (in its current as well as previous 1980 edition) lists the following clusters:
• Cluster A: antisocial (the most widely researched and oldest personality disor
der, previously known as "psychopathic"), borderline, narcissistic, and histrionic, which are characterized by odd and eccentric behaviors as well as disregard for others.
• Cluster B: schizotypal, schizoid, and paranoid, which are characterized by dra
matic, erratic, and emotional behaviors.
• Cluster C: avoidant, obsessive-compulsive, dependent, and passive-aggressive, which are characterized by anxious and fearful behaviors.
Despite widespread agreement on the above list, which is purely descriptive, main stream personality researchers are hoping that the next revision of the DSM shifts to a dimensional model of personality disorders (McCrae, Loeckenhoff, & Costa, 2005). Indeed, a recent issue of the European journal of Personality (2005) was entirely
PSYCHOPATHOLOGY 131
devoted to the cause of a model that integrates normal and abnormal classifications of personality along a continuum, with a focus on psychometric inventories (both self-and other-reports) rather than the currently dominant unstructured interviews (Westen, 1997). Thus Widiger and Samuel (2005, p. 279) argued that "few clinicians would attempt to diagnose mental retardation in the absence of a structured test, yet this is the norm for most other diagnoses."
Trull and Durrett (2005) proposed a dimensional model that conceptual izes abnormal and normal personality in terms of four common factors; namely, Neuroticism I negative affect/ emotional dysregulation, Extraversion I positive affect, dissocial/ antagonistic behavior, and Conscientiousness/ constraint/ compulsivity. This taxonomy is consistent with several previous studies (e.g., Austin & Deary, 2000; Livesley,Jang, & Vernon, 1998; O'Connor & Dyce, 2001) and suggests that, except for Openness to Experience, the same latent factors cause responses to both clinical and nonclinical personality inventories, which implies that they can be simultaneously used to describe normal and abnormal patterns of behavior. Accordingly, it should be possible to use specific levels and combinations of the Big Five personality traits to describe and predict personality disorders, but which ones?
In a recent meta-analysis of more than 15 studies (1967-2001), Saulsman and Page (2004) looked at the particular combination of the Big Five associated with each per sonality disorder, as well as the recurrent pattern of Big Five correlates of personality disorders. Table 4.3 summarizes these findings.
As can be seen, most personality disorders were positively correlated with Neuroticism (N), and negatively correlated with Agreeableness (A) and Conscientiousness (C). The Extraversion (E) and Openness (0) correlates of personality disorders are more variable in both direction and strength. For instance, people with histrionic personality disorder tend to be substantially higher on E, while those with avoidant personality disorder tend to be substantially lower on E. 0, on the other hand, was negatively associated with schizoid but positively associated with histrionic personality disorders. The mean effects suggest that N (positively) is the most significant correlate of personality disorders, followed by A (negatively).
A clear advantage of incorporating a dimensional model in psychopathology would be the capacity to explain the stability of personality disorders, as these are extreme variations of genetically influenced traits (Cloninger, 1987; Zuckerman, 1991). Normal traits, such as the Big Five, are fairly stable throughout the lifespan, with typical reliabilities in the region of .50 over a 10-year period. Drastic changes are particularly odd for Neuroticism and Extraversion (the two classic dimensions of temperament) and after the age of 30 years.
Although the notion of stability seems incompatible with the idea of treatment -
the success of psychotherapy, for instance, is largely based on the possibility of intro ducing change -this conflict is mainly apparent. Thus Costa and McCrae (1994, p. 35)
explained that "behaviors, attitudes, skills, interests, roles, and relationships change over time, but in ways that are consistent with the individual's underlying personality." Whereas personality traits are largely the product of genetic influences, "the per
sonality pathology is found in the characteristic adaptations, not the basic tendencies" (McCrae et al., 2005, p. 273). In Figure 4.9 (adapted from McCrae & Costa, 1999), we can see how biologically based personality dimensions may affect an individual's
132 PERSONALITY AND INDIVIDUAL DIFFfRfNCfS Table 4.3 The Big Five and personality disorders
DSM-IV Five Factor model personality dimensions
personality disorders N E O A C Paranoid .28**** -.12**** -.04** -.34**** -.07**** Schizoid .13**** .23**** -.12**** -.17**** -.03* Schizotypal .36**** .28**** -.01 -.21**** -.13**** Antisocial .09**** .04 .05** -.35**** -.26**** Borderline .49**** -.09**** .02 -.23**** -.23**** Histrionic .02 .42**** .15**** -.06** -.09*** Narcissistic .04 .20**** .11**** -.27**** -.OS* Avoidant .48**** -.44**** -.09**** -.11**** -.10**** Dependent .41 **** -.13**** -.11**** .05** -.14**** Obsessive- .08*** -.12**** -.07**** -.04 .23**** compulsive Mean .24 -.07 -.01 -.17 -.09 Median .20 -.12 -.02 -.19 -.09
Source: Saulsman & Page (2004), Table 5, p. 1068. Reproduced with permission from Elsevier.
adaptation and self-concept, which would in turn be affected by external influences (e.g., cultural and social norms, life events). Psychotherapy and other forms of treat- ment may be regarded as external influences, too.
4.10
SUMMARY AND CONCLUSIONS
This chapter has examined theories of psychopathology, an important area of psy chology with historical roots dating back more than 2000 years. As has been seen:
• Throughout its history, the ongoing leitmotiv of psychopathology has been
the study of abnormal behavior. Modern conceptualizations of normality are based primarily on the four conventional criteria of statistical frequency,
Characteristic adaptations goals, attitudes, beliefs
External influences Cultural norms, life events
Basic traits Neuroticism Extraversion Openness Agreeableness Conscientiousness P<;VCHOPATHOLOGY 133 Self-concept self-schemata, personal myths
FIGURE 4.9 A simplified adaptation of McCrae & Costa's (7 999) dynamic personality model
personal distress, social norms, and maladaptiveness, as well as the mental illness or diagnostic approach from mainstream clinical psychology and psy chiatry. Despite their individual weaknesses and limitations, when combined these criteria represent an important tool for identifying psychopathological symptoms and are thus widely employed.
• There is broad consensus today on the idea that most psychological disorders
are caused by a combination of genetic dispositions, known as diatheses, and situational demands, known as stress, that trigger the onset of psychopatho logical symptoms. Genetic influences on psychopathology are stronger in some mental illnesses, such as schizophrenia (the psychological disorder in which genes play the strongest role), than others, for instance eating disor ders. This is clear from the effects of medication (i.e., psychoactive drugs) and recent studies in brain processes and structure.
• A great deal of the progress of differential psychology will depend on the extent to which personality theory and psychopathology can accurately define the boundaries between normality and abnormality. This may require a shift from qualitative to quantitative or dimensional conceptions of abnormality.
134 PERSONALITY AND INDIVIDUAL DIFFERENCES
The latter has been increasingly advocated in the study of personality disor ders and regards mental illness as an extreme and maladaptive manifestation of normal personality
Chapter 5 will introduce the concept of intelligence, which, together with person ality, represents one of the two major areas of individual differences.
TEXTS FOR FURTHER READING
Beck, A.T. & Emery, G. (1985). Anxiety Disorders and Phobias: A Cognitive Perspective. New York: Basic
Books.
Heinrichs, R.W (2005). The primacy of cognition in schizophrenia. American Psychologist, 60, 229-42.
McCrae, R.R., Loeckenhoff, C.E., & Costa, P.T. (2005). A step toward DSM-V: Cataloguing person ality-related problems in living. European journal of Personality, 19, 269-86.
Szasz, T. (1960). The my th of mental illness. American Psychologist, 15, 113-18.
Walker, E.F. & Diforio, D. (1997). Schizophrenia: A neural diathesis-stress model. Psychological Review, 104, 667-85.
LEARNING OUTCOMES
BY THE END OF THIS CHAPTER, YOU SHOULD BE ABLE TO ANSWER THE FOLLOWING FIVE KEY QUESTIONS:
1. What is intelligence?
2. What is the history behind intelligence testing? 3. What does Cattell's model say about intelligence? 4. What do we know about the development of
intellectual abilities?
5. Are there many intelligences, or is there just one?
CHAPTER OUTLINE
5.2. 1 Conceptualizing Intelligence 138
5.3. 1 Ga/ton's Hereditary Genius 140 5.3.2 J.M. Cattell's Mental Test 143
5.3.3 Binet and the Origins of IQ Testing 144 5.3.4 Spearman's g Factor of General Intellectual
Ability 147
5.3.5 Thurstone's "Primary" Mental Abilities 149
5.4 CATTELL'S THEORY OF FLUID AND