PPBS

System Justification [2020]

A Politico-Psychological Analysis

Report generated

March 23, 2026

1 Study Characteristics

1.1 Items: System Justification

1.2 Sample

N=TBD

Sample description for the 2020 PPBS CINT study to be added.

2 Descriptives

2.1 Means, SD, Range, & SE

Table 1: Descriptives
Descriptives for System Justification Items
mean sd median se
SJ1 4.75 2.20 5 0.05
SJ2 4.87 2.25 5 0.05
SJ3 4.35 2.34 4 0.05
SJ4 6.23 2.45 7 0.05
SJ5 5.57 2.09 6 0.05
SJ6 5.17 2.60 5 0.06
SJ7 3.71 2.06 3 0.05
SJ8 4.67 2.17 5 0.05
Mean 4.91 1.65 5 0.04
Note:
All items: n = 2000, min = 1, max = 9. Mean: min = 1, max = 9

2.2 Response Distribution

Figure 1: Proportion of each response categories for System Justification Items
Figure 2: Distribution of reponses for System Justification Items

2.3 Correlations

Figure 3: Bivariate Spearman’s correlations for System Justification

Note. Upper triangle shows Spearman’s rank-order correlations. *** p < .001, ** p < .01, * p < .05.

Figure 4: Bivariate Spearman’s correlations for System Justification

Note. Upper triangle shows Spearman’s rank-order correlations by party identity. *** p < .001, ** p < .01, * p < .05.

Figure 5: Correlation Matrix of System Justification items, Spearman’s rank correlations

3 Demographics

3.1 Social Class

Figure 6: System Justification as grouped by SES
Figure 7: Raincloud Plots showing System Justification grouped by Social Class

Note on the Raincloud Plots

  • Statistical summary (top): Welch’s t-test (or ANOVA) results, effect size, confidence intervals, p-values, and sample sizes are shown above each plot.
  • Bayesian analysis (bottom): Log Bayes factor and credible intervals are reported below each plot.
Table 2: System Justification as grouped by SES
SES N Mean SD
Poor 154 -0.20 0.95
Lower Middle Class 405 -0.18 0.96
Middle Middle Class 786 0.01 1.04
Upper Middle Class 655 0.15 0.96

3.2 Gender

Figure 8: System Justification as grouped by Gender
Figure 9: Raincloud Plots showing System Justification grouped by Gender
Table 3: System Justification as grouped by Gender
System Justification as grouped by Gender
Gender N Mean SD
Female 1030 -0.12 0.97
Male 970 0.13 1.02

3.3 Age

Figure 10: System Justification as grouped by Age
Figure 11: Raincloud Plots showing System Justification grouped by Age
Table 4: System Justification as grouped by Age
System Justification as grouped by Age
Age N Mean SD
18-24 years 233 -0.57 1.04
25-34 years 356 -0.32 1.00
35-44 years 335 -0.03 1.00
45-54 years 331 0.03 0.95
55-64 years 332 0.30 0.94
NA 413 0.34 0.82

3.4 Education

Figure 12: System Justification as grouped by Education
Figure 13: Raincloud Plots showing System Justification grouped by Education
Table 5: System Justification as grouped by Education
Education N Mean SD
High School or less 761 -0.06 0.98
Some College 565 -0.07 1.03
Bachelor or higher 674 0.13 0.98

3.5 Income Levels

Figure 14: System Justification as grouped by Income Levels
Figure 15: Raincloud Plots showing System Justification grouped by Income Levels
Table 6: System Justification as grouped by Income Levels
System Justification as grouped by Income Levels
Income Levels N Mean SD
Less than $15,000 229 -0.14 0.95
$25,000-$34,999 187 -0.07 1.01
$15,000-$24,999 188 -0.06 0.95
$35,000-$49,999 255 -0.03 1.01
$50,000-$74,999 357 -0.02 1.03
$100,000-$149,999 290 0.06 1.04
$75,000-$99,999 243 0.09 1.00
$150,000 + 251 0.12 0.96

3.6 Ethnicity

Figure 16: System Justification as grouped by Ethnicity

Note on the Okabe-Ito color palette. The Okabe-Ito color palette (seen above) is a set of colorblind-friendly categorical colors available in R. We are using this palette for graphs with non-ordered variables (e.g., groups, categories) for accessibility.

Figure 17: Raincloud Plots showing System Justification grouped by Ethnicity
Table 7: System Justification as grouped by Ethnicity
System Justification as grouped by Ethnicity
Ethnicity N Mean SD
Black/African American 255 -0.43 0.93
Asian/Pacific Islander 99 -0.21 0.94
Native American 13 -0.46 1.21
Other 27 -0.03 0.95
NA 1516 0.11 0.98
NA 88 -0.30 1.08
NA 2 -1.42 0.16

3.7 Occupation

Figure 18: System Justification as grouped by Occupation
Figure 19: Raincloud Plots showing System Justification grouped by Occupation
Table 8: System Justification as grouped by Occupation
System Justification as grouped by Occupation
Occupation N Mean SD
Employed 994 0.03 1.00
Retired 420 0.30 0.85
Unemployed 241 -0.33 1.01
Parent 71 0.06 0.95
Disabled 114 0.01 1.01
Student 123 -0.63 1.00
Full-time caregiver 37 -0.16 1.01

3.8 Area

Figure 20: System Justification as grouped by Area
Figure 21: Raincloud Plots showing System Justification grouped by Area
Table 9: System Justification as grouped by Area
System Justification as grouped by Area
Area N Mean SD
Urban 568 -0.18 1.03
Rural 424 0.12 0.95
NA 1008 0.05 0.99

3.9 Religious Affiliation

Figure 22: System Justification as grouped by Religious Affiliation
Figure 23: Raincloud Plots showing System Justification grouped by Religious Affiliation
Table 10: System Justification as grouped by Religion
System Justification as grouped by Religious Affiliation
Religious Affiliation N Mean SD
Catholic 468 0.27 0.94
Protestant 784 0.20 0.91
Jewish 72 0.20 0.98
Muslim 11 -0.08 1.18
Atheist/Agnostic 328 -0.60 1.02
Don't know / refused 337 -0.30 0.94

3.10 Section Summary

  System Justification
Predictors Estimates CI p
(Intercept) 3.17 2.89 – 3.46 <.001
Age 0.29 0.25 – 0.33 <.001
Income 0.02 -0.01 – 0.06 .187
Education -0.01 -0.10 – 0.09 .914
Gender (Male) 0.38 0.24 – 0.52 <.001
Observations 2000
R2 / R2 adjusted .105 / .103

4 Political Behavior

4.1 Political Orientation

Figure 24: Political Orientation
Figure 25: Political Orientation (Controlled for Demographics)

Note. The y-axis shows residuals after regressing the outcome on demographics (Age, Income, Education, Gender). This illustrates how much the focal construct explains beyond demographic factors.

Figure 26: Correlation Matrix - Political Orientation
Table 11: Models of Political Orientation (SPRI) & System Justification
  Political Orientation Social Political Orientation Economic Political Orientation
Predictors Estimates CI p Estimates CI p Estimates CI p
(Intercept) 51.70 50.58 – 52.83 <.001 50.03 48.84 – 51.23 <.001 54.38 53.25 – 55.52 <.001
System Justification 16.48 15.36 – 17.60 <.001 16.95 15.75 – 18.14 <.001 17.87 16.73 – 19.01 <.001
Observations 2000 2000 2000
R2 / R2 adjusted .294 / .294 .279 / .278 .322 / .322
Table 12: Models of Ideology and System Justification with Controls
  Political Orientation Social Political Orientation Economic Political Orientation
Predictors Estimates CI p Estimates CI p Estimates CI p
(Intercept) 10.03 4.80 – 15.25 <.001 9.30 3.75 – 14.86 .001 3.77 -1.55 – 9.09 .165
System Justification 10.21 9.50 – 10.92 <.001 10.54 9.78 – 11.30 <.001 10.99 10.26 – 11.71 <.001
Age -0.21 -0.91 – 0.50 .560 -0.20 -0.95 – 0.55 .602 -0.45 -1.17 – 0.27 .220
Income -0.69 -1.26 – -0.12 .017 -0.83 -1.43 – -0.23 .007 -0.05 -0.63 – 0.52 .859
Education -0.77 -2.29 – 0.75 .320 -2.30 -3.91 – -0.68 .005 0.15 -1.40 – 1.70 .848
Gender (Male) -1.97 -4.27 – 0.32 .092 -1.26 -3.70 – 1.18 .311 -1.17 -3.51 – 1.17 .327
Observations 2000 2000 2000
R2 / R2 adjusted .300 / .298 .290 / .288 .323 / .321

4.2 Partisanship

Figure 27: Party Identity
Table 13: Mean System Justification by Party Identity
Mean System Justification by Party Identity (raw means)
Party Identity N Mean SD
Democrat 772 4.15 1.58
Republican 657 5.94 1.28
Don't Know/Other 72 4.15 1.20
Independent/Moderate 499 4.86 1.54
Table 14: Model of System Justification & Party Identity (7-point)
  System Justification
Predictors Estimates CI p
(Intercept) 3.25 3.09 – 3.41 <.001
Party Identity (7-point) 0.45 0.41 – 0.49 <.001
Observations 1429
R2 / R2 adjusted .276 / .276
Table 15: Model of System Justification & Party Identity with Controls
  System Justification
Predictors Estimates CI p
(Intercept) 1.91 1.58 – 2.24 <.001
Party Identity (7-point) 0.43 0.39 – 0.46 <.001
Age 0.21 0.17 – 0.26 <.001
Income -0.01 -0.04 – 0.03 .709
Education 0.02 -0.08 – 0.12 .717
Gender (Male) 0.42 0.28 – 0.57 <.001
Observations 1429
R2 / R2 adjusted .335 / .332

4.3 Religiosity

Figure 28: Religiosity
Figure 29: Religiosity (Controlled for Demographics)

Note. The y-axis shows residuals after regressing the outcome on demographics (Age, Income, Education, Gender). This illustrates how much the focal construct explains beyond demographic factors.

Figure 30: Religiosity - Correlation Matrix

4.4 Candidate Preferences

Figure 31: Candidate Preferences
Table 16: Candidate Preferences (centered)
Candidate Preferences and System Justification [centered]
Candidate Preference N Mean SD
Donald Trump 614 0.71 0.72
Bernie Sanders 326 -0.84 0.93
Joe Biden 326 -0.15 0.87
None/Not listed 217 -0.28 0.80
Elizabeth Warren 86 -0.86 0.86
Hillary Clinton 78 -0.27 0.84
Pete Buttigieg 75 -0.23 0.78
Ted Cruz 46 0.68 0.74
Michael Bloomberg 43 0.18 0.86
Kamala Harris 30 -0.53 0.80
Jeb Bush 29 0.21 0.85
Mitt Romney 28 0.34 0.65
Marco Rubio 26 0.85 0.69
Rand Paul 24 0.30 0.62
Amy Klobuchar 23 -0.28 0.74
Beto O'Rourke 13 -0.17 0.93
Gary Johnson 10 0.23 0.84
Jill Stein 6 -1.06 0.63
Table 17: Candidate Preferences (raw means)
Candidate Preferences and System Justification [raw means]
Candidate Preferences N Mean SD Range
Donald Trump 614 6.09 1.18 1-9
Bernie Sanders 326 3.53 1.54 1-9
Joe Biden 326 4.66 1.43 1-9
None/Not listed 217 4.46 1.32 1-9
Elizabeth Warren 86 3.48 1.42 1-9
Hillary Clinton 78 4.47 1.39 1-9
Pete Buttigieg 75 4.53 1.29 1-9
Ted Cruz 46 6.04 1.22 1-9
Michael Bloomberg 43 5.21 1.42 1-9
Kamala Harris 30 4.04 1.33 1-9
Jeb Bush 29 5.27 1.40 1-9
Mitt Romney 28 5.48 1.08 1-9
Marco Rubio 26 6.31 1.14 1-9
Rand Paul 24 5.40 1.03 1-9
Amy Klobuchar 23 4.45 1.22 1-9
Beto O'Rourke 13 4.63 1.53 1-9
Gary Johnson 10 5.30 1.39 1-9
Jill Stein 6 3.17 1.05 1-9

4.5 Party Preferences

Figure 32: Party Preferences
Table 18: Party Preferences (centered)
Party Preferences and System Justification [centered]
Party Preference N Mean SD
Green Party 22 -0.88 0.89
Democrat Party 841 -0.46 0.93
None 266 -0.27 0.85
Libertarian Party 97 -0.09 1.00
Republican Party 736 0.62 0.74
Tea Party 38 0.92 0.85
Table 19: Party Preferences (raw means)
Party Preferences and System Justification [raw means]
Party Preferences N Mean SD Range
Green Party 22 3.45 1.47 1-9
Democrat Party 841 4.15 1.54 1-9
None 266 4.46 1.41 1-9
Libertarian Party 97 4.76 1.65 1-9
Republican Party 736 5.94 1.22 1-9
Tea Party 38 6.44 1.41 1-9

4.6 Voting Preferences

Table 20: Voting Preferences
  2020 [Trump vs. Biden]
Predictors Odds Ratios CI p
(Intercept) 3.58 2.38 – 5.46 <.001
System Justification 1.21 1.11 – 1.32 <.001
Observations 2000
R2 Tjur .008
Figure 33: Logistic Regression, System Justification & Voting Preferences

4.7 Voting & Party Identity

Figure 34: Party Identity and Voting
Table 21: Party Identity & Voting
0 1
Don't Know/Other 47 25
Republican 36 621
Independent/Moderate 79 420
Democrat 41 731
Figure 35: Predicted, Voting & Party Identity
Table 22: Supporters
  2020 [Biden vs. Trump]
Predictors Odds Ratios CI p
(Intercept) 3.18 2.10 – 4.87 <.001
Party Identity (dichotomous) 0.58 0.41 – 0.82 .002
System Justification 1.31 1.19 – 1.45 <.001
Observations 2000
R2 Tjur .015

4.8 Likeability

5 Politico-Psychological correlates of System Justification


5.1 Ideologies and Partisanship

Figure 36: Correlates - Ideologies and Partisanship (by magnitude)
Figure 37: Correlates - Ideologies and Partisanship (alphabetic)

5.2 Populism, Nationalism, Nativism, and Patriotism

Figure 38: Correlates - Populism, Nationalism, Nativism, and Patriotism (by magnitude)
Figure 39: Correlates - Populism, Nationalism, Nativism, and Patriotism (alphabetic)

5.3 Political Psychology

Figure 40: Correlates - Political Psychology (by magnitude)
Figure 41: Correlates - Political Psychology (alphabetic)



5.4 Positive and Negative correlates of System Justification

Figure 42: Correlates - Positive associations
Figure 43: Correlates - Positive associations (alphabetic)
Figure 44: Correlates - Negative associations
Figure 45: Correlates - Negative associations (alphabetic)

6 Elastic Net Analysis

Figure 46: Elastic net predicting System Justification: Political Psychology
Figure 47: Elastic net predicting System Justification: Ideology & Partisanship
Figure 48: Elastic net predicting System Justification: Demographics
Figure 49: Elastic net predicting System Justification: Attitudes
Figure 50: Elastic net predicting System Justification: Everything
Table 23: Elastic Net Summary
Elastic Net R² for predicting System Justification
Variable Group # Predictors R²
Political Psychology 3 .463
Ideology & Partisanship 5 .368
Demographics 5 .112
Attitudes 3 .274
Everything 16 .571
PPBS
Psychology of Political Behavior Studies PI: Flavio Azevedo