UC Berkeley

Each of us has secrets of our own and we know others' secrets too. We share these secrets with some people and we keep these secrets from other people. This affects what we know about each other and how, in turn, we are influenced by each other.

Social science scholars have consistently found that people influence each other with regard to matters that can be observed like dropping out of school, weight gain or family structures. But of course, there are whole swaths of social life that are unobservable. The central question of this dissertation is: how do we understand social influence when people keep secrets and share them selectively?

Existing formal theories of social influence within social networks examine the structure of the network and the relationships between people. These networks are merely the potential for interpersonal communication and influence. Some work, in particular the work on diffusion, examines not just networks but communication networks. But as this inquiry will reveal, even the communication network is a potential network for the transmission of information with regard to a given topic.

This inquiry focuses not on potential communication but on realized communication and how that might differ across discussion partners and topics; it does so because communication is necessary for the influence process to occur.

I explore secrets and social influence using the test case of abortion secrets in the United States. Abortion is a highly volatile, contested secret. Tens of millions of American women have had abortions and the legality of abortion sits at the center of American politics.

I begin by examining who has abortion secrets, or abortion incidence. I calculate the first set of lifetime abortion incidence measures for birth cohorts in the United States and discuss the implications of cohort rates on public opinion and behavior. Theories of social influence suggest that the tens of millions of women who have had abortions in the United States are themselves social and political actors who can influence others, particularly their peers. Hence, scholarship on abortion as a social and political phenomenon should include incidence rates, particularly cohort incidence rates. I find that the number of lifetime abortions a birth cohort of women has differs by when they were born, even when all the cohorts have spent their entire childbearing years with federally legal abortion. Further, when cohort abortion rates decline, all racial and ethnic groups' cohort rates decline at approximately the same rate. This work is based on vital statistic rates.

I move on to how secrets spread and the implications of hearing - or not - others' secrets. I compare abortion and miscarriage secrets; this is analytically helpful for two reasons. First, they are concealable, since both are pregnancy-ending events that occur primarily in the first trimester. Abortion, however, is much more highly stigmatized than miscarriage. Second, having had at least one miscarriage is a near-random occurrence; I can thus exploit it to control for a number of otherwise unobservable characteristics that may affect whether someone hears an abortion secret, such as the prevalence of pregnancy in a respondents' social network and the frequency of discussing those pregnancies.

Though abortion is more common and affects more women than miscarriage, many more Americans report knowing someone who has had a miscarriage than an abortion. Furthermore, Americans who are anti-abortion are much less likely than their pro-choice peers to hear abortion secrets and as such think they do not know any woman who has had one. This is likely not the case. Rather, women who have had abortions and the people who know about the abortion elect to keep the abortion secret from people who may disapprove. As such, pro-choice Americans hear abortion secrets and perceive - and hence experience - a more diverse network than people who are anti-abortion and do not hear the secrets.

I show that individuals' attitudes determine what kind of community they experience; usually they experience one that aligns with their attitudes. This is not because they have chosen to be with people who agree with them or behave as they like. Rather, it is because the people they are with hide information that would reveal difference. With respect to attributes that can be kept secret, diversity is then not just a characteristic of a community but also a characteristic of individual experience of a community. When individuals keep secrets from those who will disapprove of them, processes of social influence - on public opinion, on tolerance and on behavior - are thwarted.

These results are based on a nationally representative survey I designed and conducted of over 1600 American adults who provided information on their experience with and knowledge of others' abortions and miscarriages. They also gave detailed information on disclosing and withholding their own and others' secrets.

Using the survey data, I then consider how hearing - or not - women's abortion secrets affects Americans' understanding of who gets abortions and why. We form our understandings of the world, what is possible and what is not, what is appropriate and what is not, on a number of things. We heavily weight our own experiences and those of the people we know. If our information about the experiences of those we know is distorted then that will affect our perceptions of the world, or in this case, of abortion patients.

Americans' public opinion regarding legal abortion is highly contingent on who the patient is and her reasons for seeking an abortion. Yet, I show Americans misperceive abortion prevalence, the demographic characteristics of abortion patients and their motivations. Further, their perceptions vary most consistently by the number of abortion secrets they have heard. This suggests Americans infer to the national population of abortion patients based on the patients they know of. But, as shown earlier, whose abortions they know of, is highly dependent on their attitudes.

This dissertation documents how abortions are often kept secret, particularly from Americans who are opposed to legalized abortion. As such, Americans misperceive the number of women they know who have had abortions. They then infer from their social network to the nation as a whole and similarly misperceive the abortion patient population nationally. The implications of these misperceptions are wide-ranging; this work focuses on the implications for public opinion.

In the final chapter of this dissertation, I outline where I will next take the study of secrets. I will examine a wide variety of secrets, from political attitudes to cancer diagnoses and I will employ both quantitative and qualitative methods. Americans keep abortions secret to avert stigma but there are other reasons why one might keep a secret. By extending into other arenas, I will explore these other reasons. I will also be able to capture how secret-keeping and selective disclosure affect other components of American life including the funding of scientific research and the perceptions of polarization. I hope this dissertation will stand as the first steps toward a comprehensive sociology of secrets.