Gerard Saucier

What Is Beyond the Big Five

Previous investigators have proposed that various kinds of person-descriptive content--such as differences in attitudes or values, in sheer evaluation, in attractiveness, or in height and girth--are not adequately captured by the Big Five Model. We report on a rather exhaustive search for reliable sources of Big Five-independent variation in data from person-descriptive adjectives. Fifty-three candidate clusters were developed in a college sample using diverse approaches and sources. In a nonstudent adult sample, clusters were evaluated with respect to a minimax criterion: minimum multiple correlation with factors from Big Five markers and maximum reliability. The most clearly Big Five-independent clusters referred to Height, Girth, Religiousness, Employment Status, Youthfulness and Negative Valence (or low-base-rate attributes). Clusters referring to Fashionableness, Sensuality/Seductiveness, Beauty, Masculinity, Frugality, Humor, Wealth, Prejudice, Folksiness, Cunning, and Luck appeared to be potentially beyond the Big Five, although each of these clusters demonstrated Big Five multiple correlations of .30 to .45, and at least one correlation of .20 and over with a Big Five factor. Of all these content areas, Religiousness, Negative Valence, and the various aspects of Attractiveness were found to be represented by a substantial number of distinct, common adjectives. Results suggest directions for supplementing the Big Five when one wishes to extend variable selection outside the domain of personality traits as conventionally defined.

Studies of the potential role of the dopamine D1 receptor gene in addictive behaviors.

Abnormalities in the dopaminergic reward pathways have frequently been implicated in substance abuse and addictive behaviors. Recent studies by Self and coworkers have suggested an important interaction between the dopamine D1 and D2 receptors in cocaine abuse. To test the hypothesis that the DRD1 gene might play a role in addictive behaviors we examined the alleles of the Dde I polymorphism in three independent groups of subjects with varying types of compulsive, addictive behaviors — Tourette syndrome probands, smokers and pathological gamblers. In all three groups there was a significant increase in the frequency of homozygosity for the DRD1 Dde I 1 or 2 alleles in subjects with addictive behaviors. The DRD1 11 or 22 genotype was present in 41.3% of 63 controls and 57.3% of 227 TS probands (P = 0.024). When 23 quantitative traits were examined by ANOVA those carrying the 11 genotype consistently had the highest scores. Based on these results, we examined the prevalence of the 11 genotype in controls, TS probands without a specific behavior, and TS probands with a specific behavior. There was a progressive, linear increase, significant at α ≤ 0.005 for scores for gambling, alcohol use and compulsive shopping. Problems with three additional behaviors, drug use, compulsive eating and smoking were significant at α ≤ 0.05. All six variables were related to addictive behaviors. In a totally separate group of controls and individuals attending a smoking cessation clinic, and smoking at least one pack per day, 39.3% of the controls versus 66.1% of the smokers carried the 11 or 22 genotype (P = 0.0002). In a third independent group of pathological gamblers, 55.8% carried the 11 or 22 genotype (P = 0.009 vs the combined controls). In the TS group and smokers there was a significant additive effect of the DRD1 and DRD2 genes. The results for both the DRD1 and DRD2 genes, which have opposing effects on cyclic AMP, were consistent with negative and positive heterosis, respectively. These results support a role for genetic variants of the DRD1 gene in some addictive behaviors, and an interaction of genetic variants at the DRD1 and DRD2 genes.

Studies of the 48 bp repeat polymorphism of the DRD4 gene in impulsive, compulsive, addictive behaviors: Tourette syndrome, ADHD, pathological gambling, and substance abuse.

Prior studies have reported an association between the presence of the 7 repeat allele of the 48 bp repeat polymorphism of the third cytoplasmic loop of the dopamine D4 receptor gene (DRD4) and novelty seeking behaviors, attention deficit hyperactivity disorder (ADHD), Tourette syndrome (TS), pathological gambling, and substance abuse. However, other studies have failed to replicate some of these observations. To determine whether we could replicate these associations we genotyped 737 individuals from four different groups of control subjects, and 707 index subjects from four different groups of impulsive, compulsive addictive behaviors including substance abuse, pathological gambling, TS, and ADHD. Chi-square analysis of those carrying the 7 allele versus non-7 allele carriers was not significant for any of the groups using a Bonferroni corrected alpha of.0125. However, chi-square analysis of those carrying any 5 to 8 allele versus noncarriers was significant for pathological gambling (p <.0001), ADHD (p </=.01) and the total index group (p </=.0004). When the comparison included all 7 alleles the results were significant for gamblers (p <.0001), TS (p </=.003), ADHD (p </=.003), and the total group (p </=.0002). There was a significant increase in the frequency of heterozygosity versus homozygosity for all alleles for pathological gamblers (p </=.0031) and the total index group (p </=.0015), suggesting that heterosis played a role. In the substance abuse subjects a quantitative summary variable for the severity of drug dependence, based on the Addiction Severity Index, showed that the scores varied by increasing severity across the following genotypes: 44 </= heterozygotes </= 77 </= 22. Studies of other quantitative traits indicated an important role for the 2 allele and the 22, 24, and 27 genotypes. All studies indicated that the role of the DRD4 gene in impulsive, compulsive, addictive behaviors is more complex than a sole focus on the 7 versus non-7 alleles.

Isms and the structure of social attitudes.

Social attitude measurement has been limited by inadequate structural models. In this study, broad, basic dimensions were sought, with the assumption that crucial variables are represented as terms ending in -ism (isms). 266 isms were extracted from a dictionary, and items were built from their definitions. In a sample of 500 college students, the most replicable item structure had 3 factors; one of these 3 factors split into 2 factors in the 4-factor structure. A replication study confirmed that Conservatism and Authoritarianism are subcomponents of the largest factor. The other factors, though highly meaningful, seem more sparsely represented in previous research. No factor was highly related to personality traits other than Openness to Experience. The factors can serve as content-validity benchmarks for developing improved measurement models in this consequential, discrete domain of individual differences.

Lexical Studies of Indigenous Personality Factors: Premises, Products, and Prospects

The rationale for lexical studies rests on the assumption that the most meaningful personality attributes tend to become encoded in language as single-word descriptors. We articulate some key premises of the lexical approach and then review a number of studies that have been conducted examining the factor structure of personality descriptors extracted from dictionaries. We compare lexical studies in English and 12 other languages, with attention to delineating consistencies between the structures found in diverse languages. Our review suggests that the Anglo-Germanic Big Five is reproduced better in some languages than in others. We propose some organizing rules for lexical factor structures that may be more generalizable than the contemporary Big-Five model. And, we propose several candidate structural models that should be compared with the Big Five in future studies, including structures with one, two, and three very broad factors, an alternative five-factor structure identified in Italian and Hungarian studies, and a seven-factor structure represented in Hebrew and Philippine studies. We recommend that in future studies more attention be paid to middle-level personality constructs and to examining the effects of methodological variations on the resulting factor structures.

Hierarchical subcomponents of the Big Five personality factors: A cross-language replication.

An ideal structural representation of personality attributes would include more than just broad-bandwidth factors. Specific subcomponents help define broad factors while enhancing the fidelity of the representation. There has been no consensus with regard to the necessary specific subcomponents of the Big Five. This problem was addressed by analyzing 2 representative lexical data sets, one involving English adjectives and the other involving German adjectives. Large samples (Ns of 636 and 775) were used in classifying a selection of 500 adjectives in each language by Big Five domains, and within each domain and language, the terms were factor analyzed with promax rotation. Ratings by 22 bilinguals of correspondence between the adjectives in English and German factors indicated 18 distinct content themes common to personality description in the 2 languages. The 18 subcomponents delineate necessary features of a more finely faceted measurement model for the lexical Big Five factors.

Evidence for the Big Five in analyses of familiar English personality adjectives

Studies of the natural language are a prime source of the Big‐Five model, yet the factor analysis of a large, representative, and non‐clustered set of English‐language personality adjectives in a large sample has not yet been published. In order to test the hypothesis that finding the Big Five depends on biasing the variable selection with an investigators preferred non‐familiar terms, we present the factor analysis of 435 familiar adjectives in a combined sample (N=899) of 507 self‐ and 392 peer ratings. The five‐factor solution reproduced the Big Five with high clarity, demonstrating generally very high correlations with Goldbergs adjective markers of the Big Five. The Intellect factor had a more moderate correlation, due to its de‐emphasis of the creativity components of Factor V, a phenomenon that may occur commonly with the lexical Intellect factor.

Cannabinoid receptor gene ( CNR1 ): association with IV drug use

The receptors for tetrahydrocannabinol, the active ingredient of marijuana, have been identified. A microsatellite polymorphism (AAT)n at the cannabinoid CB1 (brain) receptor gene (CNR1) consists of 9 alleles. Since the cannabinoid system is part of the reward pathway we examined the hypothesis that genetic variants of the CNR1 gene might be associated with susceptibility to alcohol or drug dependence. The study consisted of 92 subjects on an Addiction Treatment Unit (ATU) and 114 controls. All were non-Hispanic Caucasians. The ATU subjects were screened for all types of substance dependence using the Diagnostic Interview Schedule (DIS), and for a variety of substance abuse symptoms using the Addiction Severity Index (ASI). Since inspection of the distribution of alleles in controls vs IV drug use showed a decrease in the frequency of the 4 allele, and the <4 alleles were rare, the alleles were divided into two groups, <5 and ≥5, and three genotypes <5/<5, heterozygotes, and ≥5/≥5. when all variables were subjected to factor analysis, factor 1 showed a clustering of drug dependence variables and factor 2 of alcohol dependence variables. by anova only factor 1 showed significant differences by genotype consistent with a model where homozygosity for the ≥5 repeat alleles showed the greatest effect. the number of iv drugs used was significantly greater for those carrying the ≥5/≥5 genotype than for other genotypes (P = 0.005). The association with specific types of drug dependence was greatest for cocaine, amphetamine, and cannabis dependence. The results are consistent with a role of cannabinoid receptors in the modulation of dopamine and cannabinoid reward pathways. Independent studies should be designed to further confirm the hypothesis that cannabinoid receptors may contribute to the susceptibility to drug abuse.

Comparison of the role of dopamine, serotonin, and noradrenaline genes in ADHD, ODD and conduct disorder: multivariate regression analysis of 20 genes

The present study is based on the proposal that complex disorders resulting from the effects of multiple genes are best investigated by simultaneously examining multiple candidate genes in the same group of subjects. We have examined the effect of 20 genes for dopamine, serotonin, and noradrenergic metabolism on a quantitative score for attention deficit hyperactivity disorder (ADHD) in 336 unrelated Caucasian subjects. The genotypes of each gene were assigned a score from 0 to 2, based on results from the literature or studies in an independent set of subjects (literature‐based scoring), or results based on analysis of variance for the sample (optimized gene scoring). Multivariate linear regression analysis with backward elimination was used to determine which genes contributed most to the phenotype for both coding methods. For optimized gene scoring, three dopamine genes contributed to 2.3% of the variance, p=0.052; three serotonin genes contributed to 3%, p=0.015; and six adrenergic genes contributed to 6.9%, p=0.0006. For all genes combined, 12 genes contributed to 11.6% of the variance, p=0.0001. These results indicate that the adrenergic genes play a greater role in ADHD than either the dopaminergic or serotonergic genes combined. The results using literature‐based gene scoring were similar. An examination of two additional comorbid phenotypes, conduct disorder and oppositional defiant disorder (ODD), indicated they shared genes with ADHD. For ODD different genotypes of the same genes were often used. These results support the value of the simultaneous examination of multiple candidate genes.

Multivariate analysis of associations of 42 genes in ADHD, ODD and conduct disorder

In a previous study (Comings DE et al. Comparison of the role of dopamine, serotonin, and noradrenergic genes in ADHD, ODD and conduct disorder. Multivariate regression analysis of 20 genes. Clin Genet 2000: 57: 178–196) we examined the role of 20 dopamine, serotonin and norepinephrine genes in attention deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder (CD), using a multivariate analysis of associations (MAA) technique. We have now brought the total number of genes examined to 42 by adding an additional 22 candidate genes. These results indicate that even with the inclusion of these additional genes the noradrenergic genes still played a greater role in ADHD than any other group. Six other neurotransmitter genes were included in the regression equation – cholinergic, nicotinic, alpha 4 receptor (CHNRA4), adenosine A2A receptor (ADOA2A), nitric oxide synthase (NOS3), NMDAR1, GRIN2B, and GABRB3. In contrast to ADHD and ODD, CD preferentially utilized hormone and neuropeptide genes These included CCK, CYP19 (aromatase cytochrome P‐450), ESR1, and INS (p=0.005). This is consistent with our prior studies indicating a role of the androgen receptor (AR) gene in a range of externalizing behavors. We propose that the MAA technique, by focusing on the additive effect of multiple genes and on the cummulative effect of functionally related groups of genes, provides a powerful approach to the dissection of the genetic basis of polygenic disorders.