Evidence of Gendered Selection Effects into Public Office: Gendered Institutions, Political Ambition, and Personality Differences

Evidence of Gendered Selection Effects into Public Office: Gendered Institutions, Political Ambition, and Personality Differences Adam M. Dynes adamdynes@byu.edu Brigham Young University Hans J.G. Hassell hhassell@cornellcollege.edu Cornell College Jessica R. Preece jessica_preece@byu.edu Brigham Young University Matthew R. Miles milesma@byui.edu Brigham Young University-Idaho Abstract Women continue to be underrepresented in politics at every level. While previous research identifies many potential barriers for women, several recent empirical studies argue that significant aspects of the pipeline to office are, in fact, mostly gender neutral. Using surveys of the general population and elected local officials that measure Big Five personality traits, we provide evidence that the overall selection process into politics is not gender neutral. There are small baseline differences in the personality profiles of men and women in the general population; however, these small distinctions are significantly different from the larger variation we find between men and women 1) among the politically ambitious and 2) in local political office. Although we are agnostic about the meaning of the specific differences, it does appear that the trait of conscientiousness plays an important role in women s underrepresentation. More broadly, the existence of personality differences in these populations is evidence that the selection process into politics favors different kinds of women than men. In other words, the political pipeline is gendered. Word Count: 2,405 Abstract Word Count: 172

1 Women are underrepresented at every level of government in the United States. 1 Scholars have proposed a wide variety of reasons why elected office might be more elusive for women than for men, but they fall into roughly two broad categories: political socialization into lower levels of nascent political ambition and informal institutional barriers to officeholding. Using measures of the Big Five personality traits, we find evidence of gendered selection processes into both nascent political ambition and political office. Politically ambitious women have different personality profiles than politically ambitious men. Furthermore, female officeholders have different personality profiles than male officeholders and those differences are not the same as those found between men and women in the general population, or even among politically ambitious men and women. In other words, the path to office seems to require different personality traits for men and for women lower levels of political ambition alone cannot explain women s underrepresentation. In this brief article, we are agnostic about the meaning of the specific personality differences; our focus is on showing that these processes are, in fact, gendered that they favor different kinds of women than men. However, the content of the personality differences does provide some intriguing avenues for further study about the kinds of men and women who can successfully navigate the long pipeline to political office and the consequences for women s underrepresentation. In particular, conscientiousness seems to play contradictory role for women by differentially leading them away from political ambition but being especially necessary for them to win elections. 1 Current data on women s representation are available at http://www.cawp.rutgers.edu/currentnumbers. Women currently hold 20% to 25% of elected offices across all levels of government, including municipal government according to our own data.

2 Theoretical Framework Gender scholars have examined whether women face unique challenges in the pipeline to political office. Studies consistently show that women have lower levels of nascent political ambition than men, primarily because of gendered political socialization (Lawless and Fox 2005). Studies evaluating whether specific informal election institutions present disproportionate barriers for women have a wider variety of conclusions. Candidate recruitment seems to be gendered (Crowder-Meyer 2013). But, studies of media coverage suggest that the media covers men and women mostly similarly (Hayes and Lawless 2015); fundraising may not be much of an electoral barrier for women (Barber, Butler, and Preece 2016); and voters primarily care about partisanship and incumbency (Dolan 2014). These and other null findings form the basis of the common adage that when women run, women win (Burrell 1994). Nevertheless, most gender scholars acknowledge that reality is much more complex. Female candidates may be much better than their male counterparts and/or common research approaches may be poorly suited to statistically identify the campaign barriers women face (Pearson and McGhee 2013; Fulton 2012). We address the empirical question of whether the pipeline to political office is gendered in a different way than previous studies. Instead of studying specific elements of the process, we measure whether specific stages in the process as a whole result in different kinds of men and women navigating them successfully. We do this by identifying any differences in the Big Five personality profiles of 1) politically ambitious men and women in the general population and 2) male and female elected municipal officials. We also examine rates of progressive ambition among elected municipal officials. Political socialization processes interact with gender norms in a way that is likely to result in different types of women and men developing

3 nascent political ambition (Lawless and Fox 2005). And officeholding requires both having political ambition and then successfully navigating any campaign selection processes that might be gendered (Dittmar 2015). Hence, tracking the distribution of personality traits by sex across these stages of the political pipeline is one way to identify whether these processes are gendered and may provide clues to the ways in which they are gendered. In theorizing about how human traits interact with the political pipeline, we utilize the five-factor model or Big Five personality traits: openness, conscientiousness, extraversion, agreeableness, and neuroticism (or its opposite, emotional stability). We do so for several reasons. First, these traits consistently emerge as dominant features of individual personality and influence the level of comfort that individuals have in different social and professional environments (McCrae and Costa 2008). Second, a large body of work has found that the Big Five are associated with a wide range of political attitudes and behaviors among voters (see Gerber et al. 2011 for a review) and a new but growing literature finds that personality traits influence decision-making in office (Caprara et al. 2010; Cuhadar et al. 2016; Dietrich et al. 2012; Ramey et al. 2017). The well-established nature of the Big Five in the social sciences, including political science, makes them an ideal framework for initial analyses on how gendered institutions and socialization affect ambition and, ultimately, the traits of the men and women who represent us. Methods and Results To examine whether there are different selection processes for men and women, we examine personality traits by sex among both the general American public (using a survey of a representative sample of 1,939 American adults conducted in 2015) and elected officials (using a survey of 2,133 elected officials serving in municipal government in the U.S. conducted in

4 2016). Full details on the sample and methodology are available in the online appendix. In both samples, we asked a battery of questions designed to measure Big Five personality and questions measuring nascent political ambition in the general population and progressive ambition in the sample of municipal officials. Personality, Gender, and Nascent Political Ambition We begin by isolating the effect of personality on nascent political ambition for men and women in Figure 1 estimated from an ordered logit model (available in the appendix). We include personality traits as well as controls for income, education, party identification, ideology, and race. We asked respondents to characterize their interest in running for public office on a threepoint scale (no interest=80%, open to the possibility=16%, actively considering=1%). Figure 1 plots the predicted probability of a respondent saying that they are open to the possibility of running for higher office by gender and each personality trait level. Figure 1: The Effect of Personality Traits on Political Ambition in the General Population by Gender Note: 2015 Survey of US Adults. Points are the predicted probabilities from the ordered logistic regression model, bars are the 95% confidence interval. X-axis is the sd from the mean. Consistent with the idea that political socialization is gendered, we find an interaction effect between personality and gender on political ambition. Gender changes the nature of the

5 relationship between these traits and nascent political ambition. First, while men and women who are low in conscientiousness are similar to each other and express the highest levels of political ambition, increases in conscientiousness disproportionately decrease women s levels of nascent political ambition. A highly conscientious woman is six points less likely to be open to the possibility of running for elected office than a highly conscientious man. Second, while higher levels of agreeableness are associated with less ambition overall, that relationship is magnified among women. The influence of agreeableness on interest in running for elected office is different for men and women who score in the upper half of the distribution of agreeableness. In short, higher levels of agreeableness and conscientiousness are marked by even lower levels of nascent political ambition for women compared to men. Personality, Gender, and Selection into Office While the previous section investigated how personality and gender influence who is interested in running, this section examines whether the process of election to office has implications for the personality profiles of men and women in elected office. In other words, we are interested in finding evidence of gendered selection effects into office. Table A.7 in the appendix shows how personality traits in men and women differ in the general population versus the population of local public officials. We find that the fairly small differences between men and women in the general population are not the same as the much larger differences among men and women elected officials. Female elected officials have differentially higher levels of openness and extraversion than male elected officials compared to the general population; male elected officials have differentially higher levels of agreeableness. In other words, the overall process for obtaining political office appears to be different for men and women and reward different personality traits.

6 Table 1: Differences in Personality Traits between Men and Women in the General Population with Political Ambition and among Male and Female Elected Local Officials Openness Political Aspirants Elected Officials Difference Difference in Differences Women 2.02 (0.65) 2.10 (0.69) 0.08 Men 2.02 (0.60) 2.05 (0.64) 0.03 0.05 Conscientiousness Political Aspirants Elected Officials Difference Difference in Differences Women 2.21 (0.60) 2.70 (0.41) 0.49* Men 2.21 (0.56) 2.56 (0.51) 0.34* 0.15* Extraversion Political Aspirants Elected Officials Difference Difference in Differences Women 1.96 (0.65) 2.00 (0.67) 0.04 Men 1.94 (0.66) 1.87 (0.68) -0.07 0.11* Agreeableness Political Aspirants Elected Officials Difference Difference in Differences Women 2.20 (0.67) 2.36 (0.49) 0.16* Men 2.11 (0.65) 2.36 (0.49) 0.25* -0.09 Emotional Stability Political Aspirants Elected Officials Difference Difference in Differences Women 1.67 (0.63) 2.09 (0.68) 0.42* Men 1.85 (0.66) 2.25 (0.65) 0.40* 0.02 Note: *p<0.05, two-tailed test. Standard Deviations in parentheses. The only difference between men and women political aspirants to reach statistical significance is Emotional Stability. All differences between men and women elected officials are significant except Openness and Agreeableness. More importantly, however, we are interested in identifying the effect of the campaign selection process independent of differences in gendered ambition among men and women in the general population. Table 1 shows how personality traits in men and women differ looking only at those individuals in the general population who have the highest levels of political ambition (thus eliminating the effect of political ambition on officeholding and isolating the effects of

7 gendered institutional barriers). We find significant differences in how the selection process influences the personality of men and women who enter public office. 2 Politically ambitious women and men in the general population are similar in conscientiousness, but women in elected office have much higher levels of conscientiousness than men in local office. In other words, the electoral environment seems to require a significantly higher level of conscientiousness from women than from men. This is particularly interesting because, as Figure 1 shows, highly conscientious women are significantly less likely to have political ambition than conscientious men. Likewise, while politically ambitious men and women have similar levels of extraversion, women elected officials are significantly more extraverted. This suggests that aspects of the electoral environment select on extraversion much more for women than for men. Gender and Progressive Ambition among Political Officials Finally, we examine whether selection into to political office affects the differences between men and women in elected office who possess progressive political ambition. Figure 2 shows the progressive political ambition of men and women in the sample of elected officials. Consistent with prior research, men and women in our sample of elected officeholders show no differences in progressive ambition. In addition, the lack of differences in progressive ambition among women and men also hold when we asked local officials to indicate for which level of higher office they would be interested in running. Ten percent of women and 11% of men indicated interest in national office; 37 and 41%, respectively, indicated interest in state level office; while 48 and 49% indicated interest in higher local offices. The process of running and winning office is different for men and women, but results in women with nearly identical levels 2 Results are similar for individuals who were both actively considering and open to the possibility of seeking higher office.

8 of progressive political ambition. In other words, with women s representation, the first cuts are the deepest. Figure 2: Differences in Progressive Ambition between Men and Women among Elected Local Officials Conclusion Note: The figure shows proportion of women and men choosing each statement. Subjects were asked the following: Which of the following best characterizes your attitudes toward running for higher office in the future? Black dots indicate the mean proportion of women choosing particular response. Hollow triangles indicate the mean proportion of men choosing a response. Political scientists have studied many specific causes of women s underrepresentation in politics. In this paper, we take a very different approach we look at the cumulative effects of political socialization and electoral processes on who makes it through the political pipeline. This analysis acts as a plausibility check for existing research, which faces many empirical challenges, and identifies fruitful courses for future research. We find that there are significant differences in the personality traits of men and women who become politically ambitious and who win office. In other words, we find evidence that these selection processes are not gender neutral. This study cannot identify the precise causes of

9 this gender differentiation. However, some of the findings do point to a few likely candidates, many of which reinforce existing findings. Existing research identifies women s lower levels of political ambition as an important contributor to women s underrepresentation (Lawless and Fox 2005). We identify which kinds of women are less likely to be politically ambitious: those with high levels of agreeableness and high levels of conscientiousness. Interventions that account for this are more likely to be successful. At the same time, we find that women in political office have especially high levels of conscientiousness, suggesting that the socialization process into political ambition is selecting against the very women who are most likely to successfully navigate the electoral environment. We also find that female elected officials score particularly high on measures of extraversion. There are a number of potential causes for this, ranging from voter preferences to the gendered nature of social, political, and recruitment networks. More research on how extraversion interacts with gender to form candidate evaluations would be useful. Finally, our finding that there is no difference in progressive ambition among male and female elected municipal officials is also important for the study of women s underrepresentation. It highlights the significant selection effects that happen at this early stage of the pipeline to higher office. Overall, we find significant evidence that early campaign institutions are gendered and that this shapes which kinds of men and women can successfully navigate the pipeline to office above and beyond the ways in which gendered political socialization shapes who has political ambition.

10 References Barber, Michael, Daniel M. Butler, and Jessica Preece. 2016. Gender Inequalities in Campaign Finance. Quarterly Journal of Political Science 11 (2):219 48. Burrell, Barbara. 1994. A Woman s Place Is in the House: Campaigning for Congress in the Feminist Era. Ann Arbor: University of Michigan Press. Caprara, Gian Vittorio, Claudio Barbaranelli, Chiara Consiglio, Laura Picconi, and Philip G Zimbardo. 2003. Personalities of Politicians and Voters: Unique and Synergistic Relationships. Journal of Personality and Social Psychology 84(4):849. Crowder-Meyer, Melody Ara. 2013. Gendered Recruitment without Trying: How Local Party Recruiters Affect Women s Representation. Cambridge Univ Press. Cuhadar, Esra, Juliet Kaarbo, Baris Kesgin, and Binnur Ozkececi-Taner. 2016. Personality or Role? Comparisons of Turkish Leaders across Different Institutional Positions. Political Psychology 38(1): 39 54. Dietrich, Bryce J., Scott Lasley, Jeffery J. Mondak, Megan L. Remmel, and Joel Turner. 2012. Personality and Legislative Politics: The Big Five Trait Dimensions among US State Legislators. Political Psychology 33(2): 195-210. Dittmar, Kelly. 2015. Navigating Gendered Terrain: Stereotypes and Strategy in Political Campaigns. Temple University Press. Dolan, Kathleen. 2014. When Does Gender Matter?: Women Candidates and Gender Stereotypes in American Elections. Oxford University Press, USA. Fulton, Sarah A. 2012. Running Backwards and in High Heels: The Gendered Quality Gap and Incumbent Electoral Success. Political Research Quarterly 65 (2):303 14. Gerber, Alan S., Gregory A. Huber, David Doherty, Conor M. Dowling. 2011. The Big Five Personality Traits in the Political Arena. Annual Review of Political Science 14: 265 87. Hayes, Danny, and Jennifer L Lawless. 2015. A Non-Gendered Lens? Media, Voters, and Female Candidates in Contemporary Congressional Elections. Perspectives on Politics 13 (1):95 118. Lawless, Jennifer L., and Richard L. Fox. 2005. It Takes a Candidate: Why Women Don t Run for Office. Cambridge University Press. McCrae, Robert R., and Paul T. Costa. 2008. The Five Factor Model of Personality. In Handbook of Personality: Theory and Research, eds. Oliver P. John, Richard W. Robins, and Lawrence A. Pervin. New York: Guilford Press. Pearson, Kathryn, and Eric McGhee. 2013. What It Takes to Win: Questioning Gender Neutral Outcomes in US House Elections. Politics & Gender 9 (04):439 62. Ramey, Adam J., Jonathan D. Klingler, and Gary E. Hollibaugh, Jr. More Than a Feeling: Personality, Polarization, and the Transformation of the US Congress. Chicago, IL: University of Chicago Press.

11 General Population Study Methodology Online Appendix (Not Intended for print publication) To collect the diverse sample of the general public, we commissioned Clear Voice Research (CVR) to conduct an online survey of American adults. CVR fielded the survey in an online platform from June 12- June 25, 2015. Although marginal demographics may not fully characterize the bias in online panels (Kennedy et al. 2016), we note in the online appendix that the demographic distributions of the participants are consistent with the demographics of traditional telephone surveys and other representative samples. A sample of 1,939 subjects was recruited by Clear Voice Research to participate in a national political study from June 15-25, 2015. Clear Voice has maintained an online panel for the last eight years that is used solely for research purposes. Participants in the panel are told that they will be invited to participate in online research surveys in exchange for various incentives. Their initial registration form collects basic fields including: name, email address, postal address, gender, date of birth, and language. After completing this form, a double opt-in/confirmation email is sent to the email address. Only double opt-in/confirmed accounts are invited to participate in surveys. Following opt-in, panelists are asked to complete their profile so that they collect as many data points as possible, which increases their targeting abilities when they send the member survey invitations. Based on client specifications a sample is pulled in quota group formats. Simple randomization is used to give a representative sample of new and old members within the quota groups. Participants are invited via email to participate in the survey. For this survey, Clear Voice sent out 51,492 invitations, 2,488 began the survey (4.8% response rate) and 1,939 (77.9%) completed the entire survey.

12 The demographic characteristics of these panels closely resemble that of the United States population on several important traits. Table A.1 displays the demographics of this sample compared to American Community Survey (2014), Amazon s Mechanical Turk (adapted from Berinsky, Huber and Lenz (2012)), and a more nationally representative sample, the Annenberg National Election Study Johnston, Hall-Jameison, and Mutz (2008). Amazon s Mechanical Turk is an online marketplace where people hire laborers for a variety of tasks. Since the mid-2000 s researchers have been offering people money to participate in online survey experiments through Amazon s Mechanical Turk. Recently, scholars have spent considerable effort trying to determine the quality of the samples that are usually obtained through this service (Mullinix et al. 2015). The following table shows that this sample is much more representative of the US population on key variables than samples obtained through Amazon s Mechanical Turk and largely identical to the nationally representative sample collected in the Annenberg National Election Study. Table A.1: Summary of General Population Survey Demographics Demographics CVR 2015 Survey ACS 2014 Estimates MTurk NAES 2008 Female 49.23% 50.8% 60.1% 56.62% Age (mean years) 50 37.4 (median) 20.3 50.05 Education (% completing some college) 60.31% - - 62.86% White 80.61% 73.8% 83.5% 79.12% Black 9.13% 12.6% 4.4% 9.67% Asian 3.2% 5.0% - 2.53% Latino (a) 4.07% 16.9% - 6.3% Multi-Racial 2.27% 2.9% - 2.37% Party Identification

13 Democrat 33.75% - 40.8% 36.67% Independent 41.49% - 34.1% 20.82% Republican 24.77% - 16.9% 30.61% N 1,939-484-551 19,234 Figure A1 provides the battery of questions used to measure the personality traits of respondents to the national survey of the American public. The battery is drawn from Bem (1981). Local Public Officials Survey Methodology We also conducted a survey of elected municipal officials from across the US as part of the American Municipal Officials Survey (AMOS). The sample is similar to ones used in previous work to understand municipal officials decision-making (e.g., Butler et al. 2017), including on issues of candidate emergence (Butler and Preece 2016) since party elites look to sub-county officials for candidates for county and state offices (Crowder-Meyer 2013). Our questions concerning political ambition and personality were one of several projects in the survey. Subjects were recruited via emails with a link to the survey. We sent each potential subject three emails one to two weeks apart, inviting them to participate. The response rate of 17.8% was similar to other surveys of municipal officials (e.g., Butler and Dynes 2016). 3 The survey was conducted in two waves sent to two different samples of municipal officials. Invitations to the first wave were sent in May and June of 2016 to a sample of 27,862 elected mayors and legislators (e.g., city councilors, aldermen, supervisors, etc.) from 4,187 cities. The sample was compiled by a for-profit organization that gathers contact information and email addresses of public officials from municipalities that have a website and a population above 10,000. The organization uses webcrawler software to identify when information changes 3 Full details of the response rate and the methodology are available in the online appendix.

14 on the contact pages of each city s website and then has research assistants update its contact list of officials accordingly. Unfortunately, this approach has a high error rate. Based on Qualtrics email tracking, only 18,567 (or 67%) of the email invitations were delivered to an active email address. In addition, we looked up a sample of 832 officials in the list and found that only 44% of the email addresses were accurate. 2,165 officials answered questions on the first wave of the survey, resulting in a response rate of 17.8% based on the number of accurate emails in the list. 4 This rate is similar to those from other surveys of municipal officials (e.g., Butler and Dynes (2016) report a response rate of 23%). The second wave of the survey was conducted in June and July of 2016. The sample consisted of the email addresses of elected mayors and city councilors (or equivalent) gathered by Daniel Butler and Adam Dynes for the 2012 and 2014 AMOS (see Butler and Dynes (2016) for more details on the samples). Excluding the email addresses from the first wave resulted in a list of 29,250 emails. The email addresses from the 2012 AMOS were gathered in January through March of 2012 by a team of undergraduate research assistants who searched for the website of 26,566 US municipalities. The email addresses from the 2014 AMOS were gathered in a similar fashion in early 2014 but excluded municipalities with a population below 3,000 due to the low percentage of small towns with websites. Given that these email addresses were gathered 2 to 4 years prior to this latest survey, we knew that a large percentage of the emails and names of the officials (in the case of cities that use generic email accounts for each office) would no longer be accurate. Indeed, 26% of the emails sent through Qualtrics were undeliverable. It is likely that many more of the email addresses are no longer monitored though they remain active. 4 The 17.8% is calculated as follows: 2,165/(.4375*27,862).

15 With 1,500 officials participating, the response rate for the second round of the survey was 6.9%. Measures of Personality and Ambition To measure personality in the national survey we use a thirty-one adjective measure of personality shown in Figure A.1 (Bem 1981). In the municipal officials survey, we used the Big Five Iventory-10 (BFI-10) as shown in Figure A.2 (Rammstedt and John 2007). The BFI-10 uses two items per personality trait and has been shown to retain significant levels of reliability and validity compared to a 44-item measure of the Big Five (Rammstedt and John 2007, 203). However, Rammstedt and John (2007, 210) find the losses in reliability are greatest with the two-item measure of agreeableness. To mitigate this, we followed their recommendation of adding a third agreeableness item. To measure respondents nascent political ambition in the general population study we use a question from Lawless and Fox (2010). We asked them to indicate their attitude toward running for office in the future. Only 1% of our respondents reported actively considering running for public office, 16% said that they were open to the possibility of holding elective office in the future leaving 83% who reported absolutely no interest in holding elective office at any time in the future. In the sample of elected officials, we asked respondents to characterizes [their] attitudes toward running for a higher office in the future. Respondents had four options: It is something I would absolutely never do. ; I would not rule it out forever, but I currently have no interest. ; It is something I might undertake if the opportunity presented itself. ; It is something I definitely would like to undertake in the future. This is our measure of progressive ambition.

16 Figure A.1: Battery Used to Measure Big Five Personality Traits in National Sample The order of the items was randomized. Agreeableness is measured with items #2, 7,12,18, and 26. Conscientiousness with items #4,9,16,24, and 31. Emotional Stability with items #3,8,13, and 19. Extraversion with items #1, 6,11, 23, and 27. Openness with items #15,18,22,23,26,29 and 30.

Figure A.2: Battery Used to Measure Big Five Personality Traits in AMOS 17

18 Distribution of Personality Traits Figure A.2 provides the distribution of personality traits among men and women in the general population and the sample of local public officials. These plots provide more detail on the distribution of personality traits than what is shown in Table 1 in the text. Figure A.3: Distribution of Personality Traits by Gender in the US Population and Among Elected Municipal Officials

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21 Full Models and Alternative Models Previous work has shown that partisan considerations play a role in the realization of progressive ambition and the likelihood that those individuals will be recruited to run for higher office (Maisel, Maestas, and Stone 2006; Hassell 2016), so we include partisanship as a control in the general population models. In addition, we include controls from Sanbonmatsu et al. s (2008) survey of Mayors and State Legislators on factors that influence gendered political ambition; the third column contains these estimates. The fourth column includes controls from the sample of elected officials that are known to influence progressive ambition. We asked municipal officials to suppose that their current office was vacant and tell us the probability that an individual with similar views as themselves would be selected to fill their seat. The variable labeled Probability current seat filled by similar candidate is the numeric (0-100) percent chance that they believe their current seat would be filled with someone like themselves. We also expect ambition to be influenced by an individual s likelihood of winning. As such, we asked them to estimate the probability that someone like themselves would win an open state legislative seat, the next highest office available to all municipal officials. The variable labeled Probability similar candidate could win state legislative seat is their numeric percent chance. We include several other control variables that might influence an elected official s willingness to seek higher office. Margin of victory is a dichotomous variable that is coded one if the elected official won their last election by less than five percent of the vote. Years in office is the number of years that the elected official has been in their current position. We asked the elected officials how long they expect to be in their current office. Anticipated length in current office is the number of years they said that they planned to remain in their current position. We also asked if their current office had term limits. Those who are forced by statute to leave their

22 existing position might be more likely to seek higher office. We included a dichotomous variable coded one if the elected official was selected in an election in which their party affiliation appears on the ballot and zero if it does not. In addition to the models predicting nascent political ambition among the general population, we also ran models that included additional controls using an additional battery of questions from Sanbonmatsu et al. s (2008) survey of Mayors and State Legislators about other motivations for political ambition and gender. We asked respondents to rate the importance of the following factors in their interest toward holding elective office: influence on policy, advancing a political career, increasing business contacts, increasing social contact, fulfilling their civic duty, their dedication to a candidate, the excitement of politics, their concern about a particular issue, their desire to support a political party, and their interest in serving the public. The models shown in Table A.2-A.4 shows these results. As should be clear, these results are not substantively or significantly different from the models shown in the text. 5 Table A.2: Political Ambition by Personality and Gender General Population Elected Officials Openness 0.555 *** 0.429 ** 0.012 0.002 (0.160) (0.174) (0.045) (0.048) Extraversion 0.595 *** 0.486 *** 0.125 *** 0.115 ** (0.144) (0.158) (0.042) (0.045) Conscientiousness -0.777 *** -0.819 *** 0.010 0.045 (0.145) (0.158) (0.059) (0.063) Agreeableness -0.590 *** -0.694 *** -0.075-0.126 * (0.133) (0.151) (0.062) (0.066) Emotional Stability -0.107-0.062 0.077 * 0.076 (0.101) (0.110) (0.047) (0.050) 5 While we use these 10 factors of interest in office as controls it could also be that these factors are mediators by which personality affects ambition. As shown in the text, however, when we run the models without these controls, however, we find no substantive or significant differences.

23 Gender (Female) -0.771 *** -0.665 *** -0.075-0.028 (0.137) (0.148) (0.085) (0.091) Education: Less than High School -0.351-0.295 (0.591) (0.641) Education: High School -0.366 * -0.316 (0.193) (0.206) Education: Bachelor s Degree 0.007 0.053 (0.158) (0.171) Education: Graduate Degree 0.264 0.360 * (0.204) (0.217) Income 0.024-0.004 (0.032) (0.035) Race: Black 0.634 *** 0.532 ** (0.209) (0.234) Race: Asian 0.284 0.200 (0.312) (0.343) Race: Native American 0.232 0.232 (0.680) (0.702) Race: Hispanic 0.179 0.154 (0.299) (0.326) Race: Multi-Racial 0.660 * 0.549 (0.356) (0.381) Ideology: Liberal 0.166 0.158 (0.171) (0.187) Ideology: Conservative 0.244 0.187 (0.171) (0.185) Party ID: Democrat -0.022-0.137 (0.161) (0.180) Party ID: Republican -0.215-0.313 (0.189) (0.208) Influence Policy 0.218 *** (0.040) Political Career 0.111 *** (0.035) Business Contacts -0.048 (0.036) Social Contacts -0.042 (0.038) Civic Duty 0.073 ** (0.035) Dedication to Candidate -0.026 (0.035) Excitement of Politics 0.080 ** (0.035)

24 Issue Concerns -0.051 (0.040) Support the Party -0.088 ** (0.038) Serve The Public 0.154 *** (0.036) Term limits for Current Office -0.001 (0.005) Won Previous Election by 5% or Less 0.028 (0.136) Partisan elections -0.015 * (0.008) Current seat filled with similar candidate 0.006 *** (0.001) Years in Office -0.005 *** (0.002) Anticipated Length in Current Office -0.003 ** (0.002) Legislative spot filled with similar candidate 0.006 *** N 1938 1938 2382 2133 ***p <.01; **p <.05; *p <.1 (0.002) Table A.3: Political Ambition by Personality and Gender General Population Local Officials Openness 0.370 * 0.072 (0.215) (0.078) Conscientiousness -0.651 *** 0.005 (0.203) (0.093) Extraversion 0.407 ** 0.170 ** (0.194) (0.072) Agreeableness -0.566 *** -0.148 (0.187) (0.102) Emotional Stability -0.055 0.061 (0.135) (0.080)

25 Gender (Female) 0.647-0.202 (0.721) (0.679) Gender (Female) x Openness 0.118-0.203 (0.352) (0.135) Gender (Female) x Conscientiousness -0.470 0.277 (0.321) (0.207) Gender (Female) x Extraversion 0.187-0.056 (0.320) (0.130) Gender (Female) x Agreeableness -0.373-0.116 (0.297) (0.196) Gender (Female) x Emotional Stability -0.013 0.113 (0.232) (0.144) Education: Less than High School -0.332 (0.643) Education: High School -0.315 (0.207) Education: Bachelor s Degree 0.042 (0.171) Education: Graduate Degree 0.377 * (0.218) Income -0.007 (0.035) Race: Black 0.546 ** (0.235) Race: Asian 0.169 (0.343) Race: Native American 0.224 (0.704) Race: Hispanic 0.171 (0.326) Race: Multi-Racial 0.571 (0.384) Ideology: Liberal 0.143 (0.188) Ideology: Conservative 0.188 (0.186) Party ID: Democrat -0.118 (0.181) Party ID: Republican -0.311 (0.209) Influence Policy 0.216 *** (0.040) Political Career 0.113 *** (0.035) Business Contacts -0.045 (0.037) Social Contacts -0.045 (0.039)

26 Civic Duty 0.074 ** (0.035) Dedication to Candidate -0.025 (0.035) Excitement of Politics 0.082 ** (0.036) Issue Concerns -0.053 (0.041) Support the Party -0.089 ** (0.038) Serve the Public 0.155 *** (0.036) Term limits for Current Office -0.0003 (0.005) Won Previous Election by 5% or Less 0.033 (0.136) Partisan elections -0.015 * (0.008) Current seat filled with similar candidate 0.006 *** (0.001) Years in Office -0.005 *** (0.002) Anticipated Length in Current Office -0.003 ** (0.002) Legislative spot filled with similar candidate 0.006 *** (0.002) N 1,938 2,133 * p <.1; ** p <.05; *** p <.01 Table A.4: Political Ambition by Gender Conditional on Personality (Elected Officials) Model 1 Model 2 Model 3 Model 4 Model 5 Openness 0.002 0.069 0.005 0.002 0.006 (0.063) (0.077) (0.063) (0.064) (0.064) Extraversion 0.170 ** 0.152 ** 0.154 ** 0.154 *** 0.154 *** (0.071) (0.060) (0.060) (0.060) (0.060) Conscientiousness 0.060 0.059 0.007 0.060 0.062 (0.083) (0.083) (0.092) (0.083) (0.083) Emotional Stability 0.101 0.098 0.100 0.102 0.066 (0.067) (0.067) (0.067) (0.067) (0.079) Agreeableness -0.168 * -0.176 ** -0.173 ** -0.159-0.168 * (0.087) (0.088) (0.087) (0.101) (0.087) Gender (Female) 0.077 0.387-0.739 0.059-0.277 (0.267) (0.293) (0.533) (0.443) (0.305)

27 Term limits for Current Office -0.001-0.001-0.001-0.001-0.001 (0.005) (0.005) (0.005) (0.005) (0.005) Won Previous Election by 5% or Less 0.029 0.032 0.028 0.027 0.028 (0.136) (0.136) (0.136) (0.136) (0.136) Partisan elections -0.015 * -0.015 * -0.015 * -0.015 * -0.015 * (0.008) (0.008) (0.008) (0.008) (0.008) Current seat filled with similar candidate 0.006 *** 0.006 *** 0.006 *** 0.006 *** 0.006 *** (0.001) (0.001) (0.001) (0.001) (0.001) Years in Office -0.005 *** -0.005 *** -0.005 *** -0.005 *** -0.005 *** (0.002) (0.002) (0.002) (0.002) (0.002) Anticipated Length in Current Office -0.003 ** -0.003 ** -0.003 ** -0.003 ** -0.003 ** (0.002) (0.002) (0.002) (0.002) (0.002) Legislative spot filled with similar candidate 0.006 *** 0.006 *** 0.006 *** 0.006 *** 0.006 *** Gender (Female) x Extraversion -0.053 (0.002) (0.002) (0.002) (0.002) (0.002) (0.127) Gender (Female) x Openness -0.199 (0.134) Gender (Female) x Conscientiousness 0.266 (0.197) Gender (Female) x Agreeableness -0.037 (0.184) Gender (Female) x Emotional Stability 0.115 (0.134) N 2133 2133 2133 2133 2133 *** p <.01; ** p <.05; * p <.1

28 Figure A.4: The Effect of Personality Traits on Political Ambition Among Elected Officials by Gender Note: 2015 Survey of Local Elected Officials. Lines are the predicted probabilities from the ordered logistic regression model. Blue line is for females. Bars are the 85% confidence intervals following best practices for post estimation tests of statistical difference (Maghsoodloo and Huang 2010).

29 Figure A.5: Differences in Nascent and Progressive Ambition between Men and Women in the General Population and among Elected Local Officials Note: Proportion of women and men choosing each statement with regards to either their nascent ambition (in the case of the General Population) or progressive ambition (in the case of Elected Local Officials). In both surveys, subjects were asked the following: Which of the following best characterizes your attitudes toward funning for (higher) office in the future? Solid gray circles indicate the mean proportion of women choosing a particular response to the question. Solid black triangles indicate the mean proportion of men choosing a response. Hollow circles and triangles are predicted probability that men or women would choose each statement when controlling for other variables that may also affect ambition based on results from Tables A.5 and A.6.

30 Table A.5: Political Ambition by Gender Conditional on Personality (General Population). Source for Figure A.5 female = 1-0.330*** (0.080) educ = 2, High School -0.117 (0.339) educ = 3, Some College 0.064 (0.334) educ = 4, Bachelors Degree 0.095 (0.338) educ = 5, Graduate Degree 0.239 (0.348) income = 2 0.045 (0.126) income = 3 0.107 (0.130) income = 4-0.087 (0.147) income = 5 0.055 (0.151) income = 6-0.160 (0.192) income = 7 0.158 (0.244) income = 8-0.100 (0.265) income = 9 0.087 (0.366) income = 10 0.037 (0.247) race = 2, Asian -0.216 (0.222) race = 3, Native American -0.201 (0.399) race = 4, Hispanic -0.291 (0.210) race = 5, White -0.331*** (0.129) race = 6, Multi-Racial -0.058 (0.244) dideo = 2, Moderate -0.126 (0.106) dideo = 3, Conservative -0.040 (0.118) partyid = 2, Democrat 0.015 (0.135) partyid = 3, Lean-Democrat 0.048 (0.142) partyid = 4, Independent 0.142 (0.132) partyid = 5, Lean Republican 0.152 (0.172) partyid = 6, Republican -0.017 (0.159)

31 partyid = 7, Strong Republican -0.060 (0.163) Extraversion 0.280*** (0.087) Openness 0.214** (0.096) Agreeableness -0.364*** (0.083) Conscientiousness -0.479*** (0.088) Emotional Stability -0.027 (0.061) Influence Policy 0.112*** (0.022) Political Career 0.068*** (0.020) Business Contacts -0.027 (0.020) Social Contacts -0.024 (0.022) Civic Duty 0.039** (0.020) Dedication to Candidate -0.010 (0.019) Excitement of Politics 0.048** (0.020) Issue Concerns -0.035 (0.022) Support the Party -0.050** (0.021) Serve the Public 0.082*** (0.020) Constant cut1 0.677* (0.401) Constant cut2 2.240*** (0.406) Observations 1,938 Standard errors in parentheses *** p<0.01, ** p<0.05, * p<0.1

32 Table A.6: Political Ambition by Gender Conditional on Personality (Elected Officials) with Additional Controls. Source for Figure A.5 Gender (Female) = 1-0.041 (0.063) Openness -0.036 (0.032) Conscientiousness 0.038 (0.041) Extraversion 0.082*** (0.030) Agreeableness -0.062 (0.043) Emotional Stability 0.042 (0.034) Term limits for Current Office 0.002 (0.001) Won Previous Election by 5% or Less -0.052 (0.088) Partisan elections -0.013*** (0.004) Anticipated Length in Current Office 0.003*** (0.001) Years in Office -0.003** (0.001) Current seat filled with similar candidate -0.002* (0.001) Legislative spot filled with similar candidate 0.002** (0.001) Official Holds Mayoral Office -0.196** (0.091) Mayoral Form of Gov't 0.210* (0.119) Manager Form of Gov't 0.102 (0.121) Log of Population 0.089*** (0.021) % Pop. Minority 0.263* (0.143) % Pop. w/ Some College or More 0.245 (0.474) Constant cut1 0.098 (0.315) Constant cut2 1.454*** (0.317) Constant cut3 2.316*** (0.319) Observations 1,682 Robust standard errors in parentheses *** p<0.01, ** p<0.05, * p<0.1

33 Table A.7: Differences in Personality Traits between Men and Women in the General Population and among Elected Local Officials Openness General Population Elected Officials Difference Difference in Differences Women 1.90 (0.57) 2.10 (0.69) 0.20* Men 1.93 (0.60) 2.05 (0.63) 0.12* 0.080* Difference -0.03 0.05 Conscientiousness General Population Elected Officials Difference Difference in Differences Women 2.40 (0.50) 2.70 (0.44) 0.30* Men 2.28 (0.56) 2.56 (0.52) 0.28* 0.022 Difference 0.12* 0.14* Extraversion General Population Elected Officials Difference Difference in Differences Women 1.85 (0.64) 2.00 (0.70) 0.15* Men 1.83 (0.66) 1.87 (0.68) 0.04 0.108* Difference 0.02 0.13* Agreeableness General Population Elected Officials Difference Difference in Differences Women 2.37 (0.57) 2.36 (0.49) -0.01 Men 2.14 (0.63) 2.36 (0.49) 0.22* -0.224* Difference 0.23* 0.00 Emotional Stability General Population Elected Officials Difference Difference in Differences Women 1.73 (0.67) 2.09 (0.68) 0.36* Men 1.91 (0.66) 2.25 (0.65) 0.34* 0.021 Difference -0.18* -0.16* Note: *p<0.05, two-tailed test. Standard Deviations in parentheses.

34 References in the Appendix Bem, SL. 1981. A Manual for the Bem Sex Role Inventory. 17th ed. Palo Alto, CA: Mind Garden. Blake, Robert R., and Jane S. Mouton. 1978. The New Managerial Grid. Houston: Gulf. Cann, Arnie., and William D. Siegfried. 1987. Sex Stereotypes and the Leadership Role. Sex Roles 17(7-8):401-408. Gerber, Alan S, Gregory A Huber, David Doherty, and Conor M Dowling. 2011. The Big Five Personality Traits in the Political Arena. Annual Review of Political Science 14: 265-287. Mondak, Jeffery J. 2010. Personality and the Foundations of Political Behavior. New York: Cambridge University Press. Kennedy, Courtney et al. 2016. Evaluating Online Nonprobability Surveys. Washington, D.C.: Pew Research Center. Rammstedt, Beatrice, and Oliver P John. 2007. Measuring Personality in One Minute or Less: A 10-Item Short Version of the Big Five Inventory in English and German. Journal of Research in Personality 41 (1): 203-212.