Methods Supplement for “Do People Naturally Cluster into Liberals and Conservatives?”

We used the U.S. General Social Survey (GSS), which is a free, publicly available database ( We used years 1980 to 2014.

We selected a large number of items relating to (1) sexual and reproductive lifestyles and religious fundamentalism, (2) race, immigration, and the death penalty, and (3) government income redistribution and support for the poor and the unemployed. All were either asked in multiple waves or very similar to other items asked in multiple waves. Each item was recoded such that higher values are more conservative and “don’t know” responses were recoded as the middle value for the applicable response options. The tables below list the original GSS variable names and question wording, broken out into our three issue domains.

Religious items (part 1 of 2):

Item / Question
ABANY / Please tell me whether or not you think it should be possible for a pregnant woman to obtain a legal abortion if the woman wants it for any reason? [1=yes; 2=no]
ABCHOOSE / Do you agree or disagree . . . A pregnant woman should be able to obtain a legal abortion for any reason whatsoever, if she chooses not to have the baby. [Responses from 1=strongly agree to 5=strongly disagree.]
ABDEFCT1 / Do you think the law should or should not allow a pregnant woman to obtain a legal abortion if there is a strong chance of serious defect in the baby? [Responses from 1=definitely should allow it to 4=definitely should not allow it.]
ABDEFCTW / Do you personally think it is wrong or not wrong for a woman to have an abortion if there is a strong chance of serious defect in the baby? [Responses from 1=always wrong to 4=not wrong at all.]
ABDEFECT / Please tell me whether or not you think it should be possible for a pregnant woman to obtain a legal abortion if there is a strong chance of serious defect in the baby? [1=yes; 2=no]
ABHLTH / Please tell me whether or not you think it should be possible for a pregnant woman to obtain a legal abortion if the woman’s own health is seriously endangered by the pregnancy? [1=yes; 2=no]
ABNOMORE / Please tell me whether or not you think it should be possible for a pregnant woman to obtain a legal abortion if she is married and does not want any more children? [1=yes; 2=no]
ABPOOR / Please tell me whether or not you think it should be possible for a pregnant woman to obtain a legal abortion if the family has a very low income and cannot afford any more children? [1=yes; 2=no]
ABPOOR1 / Do you think the law should or should not allow a pregnant woman to obtain a legal abortion if the family has a very low income and cannot afford any more children? [Responses from 1=definitely should allow it to 4=definitely should not allow it.]
ABPOORW / Do you personally think it is wrong or not wrong for a woman to have an abortion if the family has a very low income and cannot afford any more children? [Responses from 1=always wrong to 4=not wrong at all.]
ABRAPE / Please tell me whether or not you think it should be possible for a pregnant woman to obtain a legal abortion if she became pregnant as a result of rape? [1=yes; 2=no]
ABSINGLE / Please tell me whether or not you think it should be possible for a pregnant woman to obtain a legal abortion if she is not married and does not want to marry the man? [1=yes; 2=no]

Religious items (part 2 of 2):

Item / Question
BIBLE / Which of these statements comes closest to describing your feelings about the Bible? The Bible is the actual word of God and is to be taken literally, word for word. The Bible is the inspired word of God but not everything in it should be taken literally, word for word. The Bible is an ancient book of fables, legends, history, and moral precepts recorded by men.
BIBLE1 / Which of these statements comes closest to describing your feelings about the Bible? The Bible is the actual word of God and it is to be taken literally, word for word. The Bible is the inspired word of God but not everything should be taken literally, word for word. The Bible is an ancient book of fables, legends, history, and moral precepts recorded by man.
BIBLEY / Here are four statements about the Bible, and I'd like you to tell me which is closest to your own view. The Bible is God's Word and all it says is true. The Bible was written by men inspired by God, but it contains some human errors. The Bible is a good book because it was written by wise men, but God had nothing to do with it. The Bible was written by men who lived so long ago that it is worth very little today.
COHABOK / Do you agree or disagree . . . It is alright for a couple to live together without intending to get married. [Responses from 1=strongly agree to 5=strongly disagree.]
COLATH / There are always some people whose ideas are considered bad or dangerous by other people. For instance, somebody who is against all churches and religion . . . Should such a person be allowed to teach in a college or university, or not?
GRASS / Do you think the use of marijuana should be made legal or not?
HOMOSEX / What about sexual relations between two adults of the same sex--do you think it is always wrong, almost always wrong, wrong only sometimes, or not wrong at all?
HOMOSEX1 / And what about sexual relations between two adults of the same sex, is it always wrong, almost always wrong, wrong only sometimes, or not wrong at all?
LIBATH / There are always some people whose ideas are considered bad or dangerous by other people. For instance, somebody who is against all churches and religion . . . If some people in your community suggested that a book he wrote against churches and religion should be taken out of your public library, would you favor removing this book, or not?
MARHOMO / Do you agree or disagree? Homosexual couples should have the right to marry one another. [Responses from 1=strongly agree to 5=strongly disagree.]
PILLOK / Do you strongly agree, agree, disagree, or strongly disagree that methods of birth control should be available to teenagers between the ages of 14 and 16 if their parents do not approve?
PILLOKY / Do strongly disagree, disagree, agree, or strongly agree that methods of birth control should be available to teenagers between the ages of 14 and 16 if their parents do not approve?
PORNLAW / Which of these statements comes closest to your feelings about pornography laws? There should be laws against the distribution of pornography whatever the age. There should be laws against the distribution of pornography to persons under 18. There should be no laws forbidding the distribution of pornography
PRAYER / The United States Supreme Court has ruled that no state or local government may require the reading of the Lord's Prayer or Bible verses in public schools. What are your views on this--do you approve or disapprove of the court ruling?
PREMARS1 / Do you think it is wrong or not wrong if a man and a woman have sexual relations before marriage? [Same response options as PREMARSX.]
PREMARSX / There's been a lot of discussion about the way morals and attitudes about sex are changing in this country. If a man and woman have sex relations before marriage, do you think it is always wrong, almost always wrong, wrong only sometimes, or not wrong at all?
SPKATH / There are always some people whose ideas are considered bad or dangerous by other people. For instance, somebody who is against all churches and religion . . . If such a person wanted to make a speech in your (city/town/community) against churches and religion, should he be allowed to speak, or not?

Racial items:

Item / Question
AFFRMACT / Some people say that because of past discrimination, blacks should be given preference in hiring and promotion. Others say that such preference in hiring and promotion of blacks is wrong because it discriminates against whites. What about your opinion -- are you for or against preferential hiring and promotion of blacks? [Responses from 1=strongly favors to 4=strongly opposes.]
CAPPUN / Do you favor or oppose the death penalty for persons convicted of murder?
DEATHPEN / Here are some measures to deal with crime. Some people are in favor of them while other people are against them. Do you agree or disagree that. . .People convicted of murder should be subject to the death penalty. [Responses from 1=strongly agree to 5=strongly disagree.]
HELPBLK / Some people think that (Blacks/Negroes/African-Americans) have been discriminated against for so long that the government has a special obligation to help improve their living standards. Others believe that the government should not be giving special treatment to (Blacks/Negroes/African-Americans). Where would you place yourself on this scale, or haven't you made up your mind on this? [Responses from 1=government help to 5=no special treatment.]
JOBAFF / Some people say that because of past discrimination, blacks should be given preference in hiring and promotion. Others say that such preference in hiring and promotion of blacks is wrong because it discriminates against others. What about your opinion—are you for or against preferential hiring and promotion of blacks? [Responses from 1=strongly favor to 4=strongly oppose.]
LETIN / Do you think the number of immigrants from foreign countries who are permitted to come to the United States to live should be increased a lot, increased a little, left the same as it is now, decreased a little, or decreased a lot?
LETIN1 / Do you think the number of immigrants to America nowadays should be increased a lot, increased a little, remain the same as it is, reduced a little, or reduced a lot?
LETIN1A / Do you think the number of immigrants to America nowadays should be increased a lot, increased a little, remain the same as it is, reduced a little, or reduced a lot?
NATRACE / We are faced with many problems in this country, none of which can be solved easily or inexpensively. I’m going to name some of these problems, and for each one I’d like you to tell me whether you think we’re spending too much money on it, too little money, or about the right amount. Are we spending too much, too little, or about the right amount on improving the conditions of Blacks?
NATRACEY / [Same opening as NATRACE] Are we spending too much, too little, or about the right amount on assistance to blacks?
NATRACEZ / [same opening at NATRACE] Are we spending too much, too little, or about the right amount on improving the conditions of Blacks?
RACDIF1 / On the average (Negroes/Blacks/African-Americans) have worse jobs, income, and housing than white people. Do you think these differences are mainly due to discrimination? [1=yes; 2=no]
RACOPEN / Suppose there is a community-wide vote on the general housing issue. There are two possible laws to vote on. Which law would you vote for? One law says that a homeowner can decide for himself whom to sell his house to, even if he prefers not to sell to (Negroes/Blacks/African-Americans). The second law says that a homeowner cannot refuse to sell to someone because of their race or color.
WRKWAYUP / Do you agree strongly, agree somewhat, neither agree nor disagree, disagree somewhat, or disagree strongly with the following statement: Irish, Italians, Jewish and many other minorities overcame prejudice and worked their way up. Blacks should do the same without special favors.

Economic items:

Item / Question
AIDUNEMP / On the whole, do you think it should or should not be the government's responsibility to provide a decent standard of living for the unemployed? [Responses from 1=definitely should be to 4=definitely should not be.]
EQINCOME / What is your opinion of the following statement? It is the responsibility of the government to reduce the differences in income between people with high incomes and those with low incomes. [Responses from 1=strongly agree to 5=strongly disagree.]
EQUALIZE / On the whole, do you think it should or should not be the government's responsibility to reduce income differences between the rich and poor? [Responses from 1=definitely should be to 4=definitely should not be.]
EQWLTH / Some people think that the government in Washington ought to reduce the income differences between the rich and the poor, perhaps by raising the taxes of wealthy families or by giving income assistance to the poor. Others think that the government should not concern itself with reducing this income difference between the rich and the poor. Here is a card with a scale from 1 to 7. Think of a score of 1 as meaning that the government ought to reduce the income differences between rich and poor, and a score of 7 meaning that the government should not concern itself with reducing income differences. What score between 1 and 7 comes closest to the way you feel?
GOVEQINC / Do you agree or disagree? It is the responsibility of the government to reduce the differences in income between people with high incomes and those with low incomes. [Responses from 1=strongly agree to 5=strongly disagree.]
HELPPOOR / I'd like to talk with you about issues some people tell us are important. Please look at CARD BC. Some people think that the government in Washington should do everything possible to improve the standard of living of all poor Americans; they are at Point 1 on this card. Other people think it is not the government's responsibility, and that each person should take care of himself; they are at Point 5. Where would you place yourself on this scale, or haven't you have up your mind on this?
JOBSALL / On the whole, do you think it should or should not be the government's responsibility to provide a job for everyone who wants one? [Responses from 1=definitely should be to 5=definitely should not be.]
MAKEJOBS / Here are some things the government might do for the economy. Circle one number for each action to show whether you are in favor of it or against it. Government financing of projects to create new jobs. [Responses from 1=strongly in favor of to 5=strongly against.]
NATFARE / We are faced with many problems in this country, none of which can be solved easily or inexpensively. I'm going to name some of these problems, and for each one I'd like you to tell me whether you think we're spending too much money on it, too little money, or about the right amount. Are we spending too much, too little, or about the right amount on welfare?
NATFAREY / [Same opening as NATFARE] Are we spending too much, too little, or about the right amount on assistance to the poor?
NATFAREZ / [same opening at NATFARE] Are we spending too much, too little, or about the right amount on caring for the poor?
SPUNEMP / Listed below are various areas of government spending. Please indicate whether you would like to see more or less government spending in each area. Remember that if you say "much more," it might require a tax increase to pay for it. Unemployment benefits. [Responses from 1=spend much more to 5=spend much less.]

The GSS does not ask all these individual items to all participants. There are several pairs of items, in fact, that have never been asked to the same individuals. Thus, it is not possible to run an overall factor analysis (even pairwise) on all the items. Instead, to produce meaningful factor analyses, individual items must be combined initially to arrive at a smaller set with less missing data per item.

We combined various items using SPSS’s “mean” function, which averages variable while minimizing missing data. First, we combined items that were identically or near-identically worded and that had identical or near-identical response options (e.g., the items AFFRMACT and JOBAFF, BIBLE and BIBLE1, HOMOSEX and HOMOSEX1, and so on). Second, we standardized and then combined (A) items that we judged to be on the same topic, despite differences in wording (e.g., the various abortion items, BIBLEY and the variable from the previous step combining BIBLE and BIBLE1, CAPPUN and DEATHPEN, and so on) as well as (B) any very highly correlated items (i.e., items correlating at a .6 or higher) (e.g., MARHOMO and the variable from the previous step combining HOMOSEX and HOMOSEX1, COHABOK and a variable combining PREMARSX and PREMARS1, and so on).

These procedures resulted in a total of twenty-four issue variables. The table below provides our names for the resulting issue variables along with the initial variables and procedures used to produce our resulting variables.

Construction of variables for factor analyses:

Resulting variables / Procedure
Abortion / ABANY, ABCHOOSE, ABDEFCT1, ABDEFCTW, ABDEFECT, ABHLTH, ABNOMORE, ABPOOR, ABPOOR1, ABPOORW, ABRAPE, and ABSINGLE (median r = .46) were each standardized and then combined.
Affirmative action / AFFRMACT and JOBAFF (r = .73) were combined as originally coded.
Biblical literalism / BIBLE and BIBLE1 (r = .87) were combined as originally coded (“Bible2”); BIBLEY and Bible2 (r not applicable) were both standardized and then combined.
Death penalty / CAPPUN and DEATHPEN (r = .77) were both standardized and then combined.
Help for blacks / HELPBLK
Help for the poor / HELPPOOR
Homeowner discrimination / RACOPEN
Homosexuality / HOMOSEX and HOMOSEX1 (r = .87) were combined as originally coded (“HomoSex2”); MARHOMO and HomoSex2 (r = .70) were both standardized and then combined.
Gov. finance jobs / MAKEJOBS
Gov. provide for unemployed / AIDUNEMP
Gov. provide jobs / JOBSALL
Immigration / LETIN, LETIN1, and LETIN1A (r = .67) were combined as originally coded.
Income redistribution / EQINCOME and GOVEQINC (r not applicable) were combined as originally coded (“GovEqInc2”); EQUALIZE, EQWLTH, and GovEqInc2 (median r = .53) were each standardized and then combined.
Marijuana legalization / GRASS
Pornography / PORNLAW
Premarital sex / PREMARS1 and PREMARSX (r = .83) were combined as originally coded (“PremarSex2”); COHABOK and PremarSex2 (r = .66) were both standardized and then combined.
Racial discrimination / RACDIF1
Rights for anti-religious / COLATH, LIBATH, and SPKATH were each standardized and then combined.
School prayer / PRAYER
Spending on blacks / NATRACE and NATRACEZ were combined as originally coded (“NatRace2”); NATRACEY and NatRace2 were both standardized and then combined.
Spending on the poor / NATFAREY and NATFAREZ were combined as originally coded (“NatFare2”); NATFARE and NatFare2 were both standardized and then combined.
Spending on unemployed / SPUNEMP
Teen birth control / PILLOK and PILLOKY were combined as originally coded.
Work way up / WRKWAYUP

These procedures came close to producing a variable set on which a pairwise factor analysis could be conducted. The only remaining obstacle was that the Immigration items were never asked simultaneously with the items for Gov. finance jobs, Gov. provide for unemployed, Gov. provide jobs, or Spending on unemployed. We therefore ran two separate exploratory factor analyses, the first excluding the Immigration variable and the second excluding the four jobs and unemployment variables. Both analyses were run pairwise and used SPSS’s Direct Oblimin rotation.