Research & Results
OutOfService.com, created by Jeff Potter, has run personality tests for over 10 million people since 1997. In addition to giving visitors instant, anonymous, and free results about their personalities, the answers gathered from test-takers have been used in collaborations with personality researchers at universities (scroll down to see paper abstracts).
Personality researchers look at how people behave, and more specifically, how you and I behave differently. "Why do I act the way I do? Why do other people act the way they do?" While we'll never have perfect answers, researchers have developed pretty good insights into the broad answers about human personality.
Like all science, personality psychology relies on both theories and data. Imagine a researcher comes up with a theory to describe our personality. Maybe a hypothesis like: "As we get older, we become more conscientious (more careful, more thoughtful, more organized)." That's a pretty simple idea, but we don't know if it's true without some data to back it up.
One common way to see if a theory is true is to gather and examine survey data. Researchers ask a large number of people a carefully designed questionnaire and then look at the differences between answers. The Internet happens to be great for gathering survey data, which is why my website has been so useful to researchers!
Going back to the hypothesis I proposed above, imagine that I had a thousand responses for how conscientious people are, with half of the surveys filled out by people in their twenties and the other half from people in their fifties. After examining the data, let's say that I find out that the fifty-somethings are indeed more conscientious on average than the younger group. That's good evidence that the theory is true!
But studies are never perfect, and scientists can overlook things. What if it turns out people in their twenties, who were born in the 1990s, are somehow different because of being born in the 90s? Maybe coming of age during the Bush era caused these twenty-somethings to be less thoughtful, and the results we came up with had nothing to do with their age but when they were born?!
This sort of oversight is why you occasionally see scientists claim one thing only to turn around a few years later and find an entirely different result. In my example of older people being more conscientious, we can check if it's age or year-of-birth by looking at data gathered across multiple years. After looking at the answers from exactly 132,515 people on this site, it doesn't appear to matter when someone was born for this particular finding. For now, we're reasonably certain that our theory about people becoming more conscientious as they get older is true.
Coming up with good theories that describe how the world works takes time. As research continues, we create more accurate models, which leads to an even better understanding of who we are and why we act the way we do. Thanks for taking the time to learn about this research and for contributing by taking a test on this site!
Here are the studies that I've worked on. My role has been primarily on the technical side; I can't claim credit for the research ideas and insights that my collaborators have gleaned from the data. I'm delighted to have provided the data that made the research possible and honored to have been included as a co-author. Plus, it's pretty cool to have created a site that so many people have used to learn more about themselves...
I'm going to break tradition and not list these studies in strict chronological order. Instead, I'm putting those papers that I feel are more accessible to non-academics ahead of the others. If you'd like to see a more complete list of publications, view my Google Scholar page. Up first? New Yorkers are neurotic.
People in New York actually are more neurotic than people in California! And yes, people in Minnesota really are nice...
A Theory of the Emergence, Persistence, and Expression of Geographic Variation in Psychological Characteristics
Perspectives in Psychological Science (2008)
Volumes of research show that people in different geographic regions differ psychologically. Most of that work converges on the conclusion that there are geographic differences in personality and values, but little attention has been paid to developing an integrative account of how those differences emerge, persist, and become expressed at the geographic level. Drawing from research in psychology and other social sciences, we present a theoretical account of the mechanisms through which geographic variation in psychological characteristics emerge and persist within regions, and we propose a model for conceptualizing the processes through which such characteristics become expressed in geographic social indicators. The proposed processes were examined in the context of theory and research on personality traits. Hypotheses derived from the model were tested using personality data from over half a million U.S. residents. Results provided preliminary support for the model, revealing clear patterns of regional variation across the U.S. and strong relationships between state-level personality and geographic indicators of crime, social capital, religiosity, political values, employment, and health. Overall, this work highlights the potential insights generated by including macrolevel perspectives within psychology and suggests new routes to bridging theory and research across several disciplines in the social sciences.
I knew it! Dog-people are more outgoing than Cat-people!
Personalities of Self-Identified "Dog People" and "Cat People"
Anthrozoos: A Multidisciplinary Journal of The Interactions of People & Animals, Vol. 23, No. 3 (2010)
Alleged personality differences between individuals who self-identify as "dog people" and "cat people" have long been the topic of wide-spread speculation and sporadic research. Yet existing studies offer a rather conflicting picture of what personality differences, if any, exist between the two types of person. Here we build on previous research to examine differences in the Big Five personality dimensions between dog people and cat people. Using a publicly accessible website, 4,565 participants completed the Big Five Inventory and self-identified as a dog person, cat person, both, or neither. Results suggest that dog people are higher on Extraversion, Agreeableness, and Conscientiousness, but lower on Neuroticism and Openness than are cat people. These differences remain significant even when controlling for sex differences in pet-ownership rates. Discussion focuses on the possible sources of personality differences between dog people and cat people and identifies key questions for future research.
Confirmed: liberals are more open-minded, creative, curious, and novelty seeking; conservatives are more orderly, conventional, and better organized.
The Secret Lives of Liberals and Conservatives: Personality Profiles, Interaction Styles, and the Things They Leave Behind
Political Psychology, Vol. 29, No. 6 (2008)
Although skeptics continue to doubt that most people are "ideological," evidence suggests that meaningful left-right differences do exist and that they may be rooted in basic personality dispositions, that is, relatively stable individual differences in psychological needs, motives, and orientations toward the world. Seventy-five years of theory and research on personality and political orientation has produced a long list of dispositions, traits, and behaviors. Applying a theory of ideology as motivated social cognition and a "Big Five" framework, we find that two traits, Openness to New Experiences and Conscientiousness, parsimoniously capture many of the ways in which individual differences underlying political orientation have been conceptualized. In three studies we investigate the relationship between personality and political orientation using multiple domains and measurement techniques, including: self-reported personality assessment; nonverbal behavior in the context of social interaction; and personal possessions and the characteristics of living and working spaces. We obtained consistent and converging evidence that personality differences between liberals and conservatives are robust, replicable, and behaviorally significant, especially with respect to social (vs. economic) dimensions of ideology. In general, liberals are more open-minded, creative, curious, and novelty seeking, whereas conservatives are more orderly, conventional, and better organized.
A study based on 1,267,218 people?! Wow! ("Check out my N value, baby!")
Age differences in personality traits from 10 to 65: Big Five domains and facets in a large cross-sectional sample
Journal of Personality and Social Psychology, Vol 100(2), Feb 2011, 330-348
Hypotheses about mean-level age differences in the Big Five personality domains, as well as 10 more specific facet traits within those domains, were tested in a very large cross-sectional sample (N = 1,267,218) of children, adolescents, and adults (ages 10-65) assessed over the World Wide Web. The results supported several conclusions. First, late childhood and adolescence were key periods. Across these years, age trends for some traits (a) were especially pronounced, (b) were in a direction different from the corresponding adult trends, or (c) first indicated the presence of gender differences. Second, there were some negative trends in psychosocial maturity from late childhood into adolescence, whereas adult trends were overwhelmingly in the direction of greater maturity and adjustment. Third, the related but distinguishable facet traits within each broad Big Five domain often showed distinct age trends, highlighting the importance of facet-level research for understanding life span age differences in personality.
As inequality rises, we become more less likely to help others. Think twice about where you live!
Income inequality and personality: Are less equal U.S. states less agreeable?
Social Science & Medicine, Vol. 72, No. 12, June 2011, pp 1978-1985
Richard Wilkinson's "inequality hypothesis" describes the relationship between societal income inequality and population health in terms of the corrosive psychosocial effects of social hierarchy. An explicit component of this hypothesis is that inequality should lead individuals to become more competitive and self-focused, less friendly and altruistic. Together these traits are a close conceptual match to the opposing poles of the Big Five personality factor of Agreeableness; a widely used concept in the field of personality psychology. Based on this fact, we predicted that individuals living in more economically unequal U.S. states should be lower in Agreeableness than those living in more equal states. This hypothesis was tested in both ecological and multilevel analyses in the 50 states plus Washington DC, using a large Internet sample (N = 674,885). Consistent with predictions, ecological and multilevel models both showed a negative relationship between state level inequality and Agreeableness. These relationships were not explained by differences in average income, overall state socio-demographic composition or individual socio-demographic characteristics.
If you speak more than one language, how you act depends on what language you're speaking!
Do bilinguals have two personalities? A special case of cultural frame switching
Journal of Research in Personality, 40, 99-120. (2006)
Four studies examined and empirically documented Cultural Frame Switching (CFS; Hong, Chiu, & Kung, 1997) in the domain of personality. Specifically, we asked whether Spanish-English bilinguals show different personalities when using different languages? If so, are the two personalities consistent with cross-cultural differences in personality? To generate predictions about the specific cultural differences to expect, Study 1 documented personality differences between US and Mexican monolinguals. Studies 2-4 tested CFS in three samples of Spanish-English bilinguals, located in the US and Mexico. Findings replicated across all three studies, suggesting that language activates CFS for Extraversion, Agreeableness, and Conscientiousness. Further analyses suggested the findings were not due to anomalous items or translation effects. Results are discussed in terms of the interplay between culture and self.
People who take personality tests online are more diverse than US college students. (Not a surprise, but one has to show this to eliminate some assumptions!)
Wired but not WEIRD: The promise of the Internet in reaching more diverse samples
Behavioral and Brain Sciences, 33: pp 94-95 (2010)
Can the Internet reach beyond the U. S. college samples predominant in social science research? A sample of 564,502 participants completed a personality questionnaire online. We found that 19% were not from advanced economies; 20% were from non-Western societies; 35% of the Western-society sample were not from the United States; and 66% of the U. S. sample were not in the 18-22 (college) age group.
State averages for openness to experience and conscientiousness predict percentage of votes for Democratic and Republican candidates.
Statewide differences in personality predict voting patterns in 1996-2004 U.S. presidential elections
In J. T. Jost, A. C. Kay, and H. Thorisdottir (Eds.) Social and Psychological Bases of Ideology and System Justification. Oxford University Press. (2009)
Political regionalism is commonly attributed to differences in historical settlement patterns, social class, and racial diversity. The present work provides evidence for the importance of another factor—state-level personality in understanding regional differences in political ideology. Drawing on research in personality and social psychology, we propose that geographical differences in voting patterns partially reflect differences in the psychological characteristics of individuals living in different states. Specifically, we examine associations between state-level personality scores and voting patterns in the 1996, 2000, and 2004 U.S. Presidential elections. Results show that mean levels of openness and conscientiousness within a state predict the percentage of votes for Democratic and Republican candidates. Furthermore, state-level personality scores account for unique variance in voting patterns, even after adjusting for standard sociodemographic and political predictors. This work demonstrates the value of investigating psychological variables at a regional level to better understand political culture and ideology.
Using online personality tests appears to be as good as traditional survey methods for genetic epidemiology.
A Web-Based Study of Personality, Psychopathology and Substance Use in Twin, Other Relative and Relationship Pairs
Twin Research and Human Genetics, Vol. 12 No. 2 (2009)
Web-based studies have become increasingly common in the social sciences, but have been rare in genetic epidemiology in general and twin studies in particular. We here review the methods, validity checks and preliminary correlational data from an on-line questionnaire collected from 2005-2008. During this time period, 44,112 individuals completed the questionnaire. This sample was 65.3% female, 85.4% 18 years or older, 72.0% Caucasian and had a mean educational level of 12.2 years. The sample included 609 twin, 333 sibling and 201 parent-offspring pairs as well as 342 dating partners, 313 'significant other' pairs, 327 spouses and 2,316 friend pairs. A range of checks suggested low levels of invalid data. Correlations for personality, substance use and misuse, lifetime major depression, social attitudes, educational status, and height and weight were broadly similar to those obtained previously using conventional assessment methods. Web-based studies are a relatively easy and inexpensive way to ascertain large numbers of individuals, although obtaining twin pairs is more difficult, and female and monozygotic pairs are overrepresented. The sample is diverse and pair resemblance is generally similar to that obtained using interviews or mailed questionnaires.
Okay, dear reader, you're on your own for reading through the rest of these.
The Regional Distribution and Correlates of an Entrepreneurship-Prone Personality Profile in the United States, Germany, and the United Kingdom: A Socioecological Perspective
Journal of Personality and Social Psychology (2013)
In recent years the topic of entrepreneurship has become a major focus in the social sciences, with renewed interest in the links between personality and entrepreneurship. Taking a socioecological perspective to psychology, which emphasizes the role of social habitats and their interactions with mind and behavior, we investigated regional variation in and correlates of an entrepreneurship-prone Big Five profile. Specifically, we analyzed personality data collected from over half a million U.S. residents (N=619,397) as well as public archival data on state-level entrepreneurial activity (i.e., business-creation and self-employment rates). Results revealed that an entrepreneurship-prone personality profile is regionally clustered. This geographical distribution corresponds to the pattern that can be observed when mapping entrepreneurial activity across the United States. Indeed, the state-level correlation (N=51) between an entrepreneurial personality structure and entrepreneurial activity was positive in direction, substantial in magnitude, and robust even when controlling for regional economic prosperity. These correlations persisted at the level of U.S. metropolitan statistical areas (N=15) and were replicated in independent German (N=19,842; 14 regions) and British (N=15,617; 12 regions) samples. In contrast to these profile-based analyses, an analysis linking the individual Big Five dimensions to regional measures of entrepreneurial activity did not yield consistent findings. Discussion focuses on the implications of these findings for interdisciplinary theory development and practical applications.
Does self-esteem account for the higher-order factors of the Big Five?
Journal of Research in Personality, Vol. 43, No. 5, 921-922 (2009)
The purpose of this study was to determine whether higher-order factors of the Big Five personality factors are artifacts of self-esteem. Based on previous research, it was predicted that two higher-order factors, Stability and Plasticity, would emerge from correlations among the Big Five factors. It was also predicted that self-esteem would be related to the higher-order factors but would not account for them. The Big Five and self-esteem were measured in a sample of 628,640 participants using an interactive website on the Internet. Results showed that the two higher-order factors of the Big Five existed and were substantially correlated with self-esteem but remained intact when self-esteem was statistically controlled, indicating that they are not artifacts of self-esteem.
The Big Five Inventory (BFI) - Dutch version. Reliability, validity, and factorial invariance across age groups and languages
Journal of Personality Assessment, Vol. 90, No. 2, pp 152-157 (2008)
In this article, we describe the translation and validation of the Dutch Big Five Inventory (BFI; John & Srivastava, 1999), a short instrument designed to measure the Big Five factors of personality. We obtained evidence of the instrument's good psychometric properties in terms of factorial equivalence to the English original and other BFI translations and the relative independence and internal consistency of the five scales. The findings suggest that the instrument can be used in diverse age groups without substantial changes in factor structure. The Dutch BFI scales showed similar demographic correlates as the English original, with higher Agreeableness and Conscientiousness and lower Neuroticism values in older participants, higher Neuroticism values in women, and higher Openness and Conscientiousness values in better educated participants. Use of the Dutch BFI will allow researchers to integrate their findings with the extant Big Five research literature. The brevity of the instrument will be appealing to researchers who are concerned about taxing the time and motivation of their participants.
The developmental psychometrics of Big Five self-reports: Acquiescence, factor structure, coherence, and differentiation from ages 10 to 20
Journal of Personality and Social Psychology (2008)
How do youths' personality reports differ from those of adults? To identify the year-by-year timing of developmental trends from late childhood (age 10) to early adulthood (age 20), the authors examined Big Five self-report data from a large and diverse Internet sample. At younger ages within this range, there were large individual differences in acquiescent responding, and acquiescence variability had pronounced effects on psychometric characteristics. Beyond the effects of acquiescence, self-reports generally became more coherent within domains, and better differentiated across domains, at older ages. Importantly, however, different Big Five domains showed different developmental trends. Extraversion showed especially pronounced age gains in coherence but no gains in differentiation. In contrast, Agreeableness and Conscientiousness showed large age gains in differentiation but only trivial gains in coherence. Neuroticism and Openness showed moderate gains in both coherence and differentiation. Comparisons of items that were relatively easy versus difficult to comprehend indicated that these patterns were not simply due to verbal comprehension. These findings have important implications for the study of personality characteristics and other psychological attributes in childhood and adolescence.
Normality evaluations and their relation to personality traits and well-being.
Journal of Personality and Social Psychology, 93, pp 861-879. (2007)
Despite frequent discussions of what it means to be normal in clinical, social, and personality psychology theory, the characteristics of individuals who call themselves normal are little understood. In 5 studies, the authors investigated various hypotheses concerning the nature of normality evaluations. The authors add to recent evidence that normality evaluations represent a distinct dimension of evaluative judgments, showing self-judgments of being normal (versus strange) to be relatively independent from self-judgments of being average (versus unique). Normality evaluations showed positive relations with communal traits such as agreeableness, conscientiousness, and emotional stability, and were negatively related to openness to experience. Supporting a broader hypothesis that normality evaluations may be involved in directing or motivating personality development processes, normality evaluations were positively associated with well-being and a sense of fitting in with one's peers, and individuals who felt abnormal felt a heightened sense that they needed to improve their personality. Finally, the personality correlates of normality evaluations were found to change over the lifespan, largely in parallel with the actual mean-level development of personality traits with age.
Development of the Big Five in Adulthood: Set like plaster or persistent change?
Journal of Personality and Social Psychology (2003)
Different theories make different predictions about how mean levels of personality traits change in adulthood. The biological view of the Five-factor theory proposes the plaster hypothesis: All personality traits stop changing by age 30. In contrast, contextualist perspectives propose that changes should be more varied and should persist throughout adulthood. This study compared these perspectives in a large (N = 132,515) sample of adults aged 21-60 who completed a Big Five personality measure on the Internet. Conscientiousness and Agreeableness increased throughout early and middle adulthood at varying rates; Neuroticism declined among women but did not change among men. The variety in patterns of change suggests that the Big Five traits are complex phenomena subject to a variety of developmental influences.
Global self-esteem across the lifespan
Journal of Psychology and Aging (2002)
This study provides a comprehensive picture of age differences in self-esteem from age 9 to 90 years using cross-sectional data collected from 326,641 individuals over the Internet. Self-esteem levels were high in childhood, dropped during adolescence, rose gradually throughout adulthood, and declined sharply in old age. This trajectory generally held across gender, socioeconomic status, ethnicity, and nationality (U.S. citizens vs. non-U.S. citizens). Overall, these findings support previous research, help clarify inconsistencies in the literature, and document new trends that require further investigation.
Personality correlates of self-esteem
Journal of Research in Personality (2001)
The current study examined the relation between self-esteem and the Big Five personality dimensions. Data were collected over the Internet from a large heterogeneous sample of individuals who ranged in age from 9 to 90 years (N = 326,641). Collectively, the Big Five accounted for 34% of the variance in self-esteem. High self-esteem individuals were emotionally stable, extraverted, and conscientious and were somewhat agreeable and open to experience. Despite an extensive search for potential mediators and moderators of this general pattern, the relations between self-esteem and the Big Five largely cut across age, sex, social class, ethnicity, and nationality (United States vs non-United States). High self-esteem individuals tended to ascribe socially desirable traits to themselves, and this tendency partially mediated relations between the Big Five and self-esteem. Discussion focuses on interpreting the social desirability effects, limitations of the study, and directions for future research.