Saturday, November 06, 2004

Information Divergence in Political Affiliation

The way that we process the information around us leads ultimately to the decisions we make. One such decision is our choice of political affiliation. Is our choice of political party the result of the characteristic way in which we have learned to process information, i.e. our personality, or is it the result of our calculation of a number of issues? It turns out that our personality plays a statistically significant role in our political outlook. This fact is a major result of a study of blog readers conducted over the month of October. The preliminary results of this study also tells us something of how we differ.

The vast majority of respondents to the personality-political affiliation study were solicited from the political discussion websites PoliPundit and DailyKos. Both sites are dominant attractors of those interested in political discussion and news from the right and left, respectively. Both allow the posting of user comments in regard to topics of interest. The DailyKos is somewhat less restrictive as it also allows the posting of user created threads of discussion while Polipundit threads are topic driven (here a link to the study was provided by the site administrators). It is expected that these two sites would generate respondents representative of the political core of the two US political parties.

The study used the Myers-Briggs test to measure personality. The Myers-Briggs dimensions are translated here as values between 100 and −100 with the positive values corresponding to the INTJ personality type (negative values to ESFP). Each question has equal absolute value. The total value of the questions per respondent along a dimension is divided by the number of questions answered, scaled to the range, and rounded to the nearest integer. Zero is arbitrarily assigned a unit value for representation to the respondent by Humanmetrics. Here, the zero totals are reassigned to zero before data analysis. The basic statistics of the respondents are summarized below.

Single Factor Summary Statistics (mean / std)

Group

Number

Focus

Processing

Decision
Making

Organizing

Age

Weak

45

31.98 /
40.99

36.80 /
36.13

22.80 /
38.57

22.40 /
36.87

38.00 /
9.50

Strong

222

21.99 /
44.78

42.21 /
34.65

13.77 /
39.36

18.92 /
43.65

39.21 /
11.16


Male

166

23.30 /
44.31

40.50 / 34.07

25.15 /
35.85

20.83 /
41.10

38.83 /
11.41


Female

101

24.29 /
44.36

42.61 /
36.36

−0.90
/ 39.52

17.33 /
44.91

39.31 /
10.03

Conservative

137

21.45 /
42.63

33.60 /
33.60

28.73 /
37.04

30.57 /
40.68

39.83 /
11.51


Liberal

130

26.02 /
45.94

49.41 /
34.52

1.13 /
36.66

7.85 /
41.46

38.14 /
10.16


The greatest difference between conservatives and liberals appears to arise along the decision making dimension. However, it is noted that there is also a gender distinction between the respondents in this same dimension. To investigate whether this gender gap is the reason for the political distinction, we need to separate by gender and look more closely. The double factor summary statistics are shown next.

Double Factor Summary Statistics (mean / std)

Group

Number

Focus

Processing

Decision
Making

Organizing

Age

Weak Con

29

27.97 / 43.47

40.66 / 27.33

30.10/ 34.55

28.00/ 39.08

38.83 / 10.07

Strong
Con

108

19.70 / 42.44

31.70 /
34.96

28.37 / 37.83

31.26 / 41.25

40.10 /
11.90

Weak Lib

16

39.25 / 36.25

29.81 / 48.51

9.56 / 42.97

12.25 / 31.09

36.50 / 8.46

Strong Lib

114

24.16 / 46.97

52.17 / 31.39

−0.05
/ 35.75

7.22 / 42.79

38.37 /
10.39

Weak Male

26

32.00 / 41.16

39.58 / 29.51

33.35 / 32.59

23.50 / 39.09

38.08 / 10.34

Strong
Male

140

21.69 / 44.83


40.67 /
34.94


23.63 /
36.32

20.33 /
41.58

38.96 / 11.62

Weak
Female

19

31.95 /
41.92

33.00 /
44.21

8.37 /
42.21

20.89 /
34.60

37.89 /
8.49

Strong
Female

82

22.51 /
44.97

44.84 /
34.22

−3.05
/ 38.83

16.50 /
47.12

39.63 /
10.37


Male Con

109

21.97 /
43.61

35.58 /
35.12

33.27 /
35.06

29.52 /
39.24

39.31 /
11.50

Male Lib

57

25.84 /
45.89

49.91 /
30.03

9.63 /
32.28

4.21 /
39.76

37.89 /
11.27

Female Con

28

19.43 /
39.24

25.89 /
25.96

11.11 /
39.88

34.64 /
46.44

41.86 /
11.55

Female Lib

73

26.15 /
46.30

49.03 /
37.85

−5.51
/ 38.67

10.68 /
42.79

38.33 /
9.28


Under the assumption of normality, there is less than a 6% probability that female repondents are not differentiated by their decision making metrics while there is a statistically insignificant possiblitiy that the same is true in the case of the males by the two-sample t-test. As a result of the Lilliefors test of normality at a significance level of 0.05, we find that all samples except male conservatives can be assummed to satisfy the normality condition. This is likely due to the fact that the mean decision making index for male conservatives is much higher than the center of the finite index. Therefore, to satsify the hypothesis we will examine the statistical breakdown of male conservatives in the study a bit closer. The relevant triple factor statistical summary is shown below.

Selected Triple Factor Summary Statistics
Strong Political Affiliation (mean / std)


Group

Number

Focus

Processing

Decision
Making

Organizing

Age

Male Con

88

20.41 /
43.87


33.63 /
36.02

33.38 /
35.29

31.15 /
38.89

39.34 /
11.75


Male Lib

52

23.85 /
46.75

52.60 /
29.71

7.13 /
32.10

2.04 /
39.88

38.32 /
11.49


Female Con

20

16.60 /
36.28

23.25 / 29.17

6.35 /
41.61

31.75 /
51.56

43.45 /
12.28


Female Lib

62

24.42 /
47.54

51.81 /
32.98

−6.08
/ 37.74

11.58 /
44.94

38.40 /
9.46



While the standard deviations of the male conservative (both strong and weak) and strong male conservative subsamples are very nearly equal as is likewise the case for the liberal males, the mean of the strongly partisan samples are even more greatly separated along the decision making dimension than the combined samples. Therefore the lack of normality of the strong conservative male sample is such that the distinction would be even greater than what one would expect had the subsample satisfied the Lilliefors test. We therefore conclude that there is a statistically significant difference between the way in which politically affiliated liberals and conservatives process information. Specifically, liberals are more feeling while conservatives are more thinking.


An explicit discrimination of the sample described by the model is shown here.


Data available by e-mail request.