Background. Research on online privacy often reveals gender differences, e.g. in online privacy concerns (Garbarino & Strahilevitz, 2004; Hoy & Milne, 2010; Moscardelli & Divine, 2007; Youn & Hall, 2008), privacy protection and privacy behaviors (Fogel & Nehmad, 2009; Saeri et al., 2014), and willingness to disclose personal information (Acquisti & Gross, 2006; Brandtzaeg et al., 2010; Valkenburg et al., 2011; Youn, 2005). In some cases, the complexity of gender is reduced to its properties as an additional explaining variable. In contrast, other studies present a fine-grained synopsis of a specific gender theory and privacy-related approaches. Researchers might view gender as a relevant construct from the beginning and therefore thouroughly derive hypotheses along the lines of a gender theory, or they might discuss exploratory findings afterwards.

Objectives. As gender effect are often a byproduct of these studies rather than the main research aim, they vastly differ in how they theorize gender. With a systematic literature review, we wanted to map out how gender is embedded in studies on online privacy and if – and how – gendered results are discussed. We aimed to provide an overview of current state of gender theorizing in this domain and present the most important gender theories. Moreover, we wanted to identify insufficiencies in gender theorizing and sensitize for the impact thereof.

Research questions. Firstly, we wanted to determine to what extent gender theory is implemented in online privacy research (RQ1). Gender can be (i) theorized explicitly, a specific gender theory is presented; it can be (ii) theorized implicitly, i.e. the general mechanisms and language use corresponds to certain gender theories, but they are not mentioned directly; it can be treated in a (iii) quasi-theoretical manner, i.e. hypotheses and/or research questions are developed on the basis of earlier empirical findings; or research can be (iv) atheoretical with regard to gender.

Secondly, we wanted to identify the function of gender theory within the study, if applied (RQ2). Gender theories can serve either (i) as a framework for establishing hypotheses or (ii) interpreting empirical results, or they can be (iii) the result of (exploratory) research itself (Gough et al., 2012; Trauth, 2013).

Thirdly, we wanted to demonstrate the specific gender theories in use in online privacy research (RQ3). These theories might be gender theories in the narrower sense, i.e. sociopsychological models, or in the broader sense, including even non-scientific concepts that can guide online privacy research.

Method. We conducted a computer-based literature search in seven principal and four supplementary databases. We reviewed the abstracts of the resulting N = 496 articles with regard to the following criteria: Citations had to be (a) peer-reviewed research papers (b) published in English (c) as academic journal articles or conference papers (d) on or before December 2019. They had to qualify as (e) experimental (including online, lab, and quasi-experimental) studies, cross-sectional and longitudinal surveys, qualitative studies, or content analysis. Furthermore, (f) the design had to include gender (or sex) as a variable, e.g. as an independent, control or moderator variable. Our final sample consisted of n = 107 studies, which we read and classified based on formal characteristics such as publication year and affiliation, methodological characteristics, e.g. sample size and design, and mean age. The core construct of the coding scheme reflects the theoretical framework as presented in our research questions.

Findings. In RQ1, we asked to what extent gender theory is applied in studies dealing with gender in online privacy and self-disclosure. We classified n = 23 of the studies as explicit in how they theorize gender (22%); n = 28 as implicitly theoretical (26%); n = 40 studies as quasi-theoretical (37%); and n = 16 studies as not employing theory at all (15%).

In RQ2, we asked which functions gender theories have in privacy research. We found evidence for the first function, theory as a framework for hypotheses, in n = 69 studies (64%) of our sample. Theory as a guideline for discussing empirical results occurred in n = 22 studies (21%). We found no instances of theory as the product of the empirical investigation itself. The remaining n = 16 articles (15%) constitute atheoretical studies; therefore, no functional purpose of gender theory can be determined.

With RQ3, we examined the specific gender theories and broader, even non-scientific concepts that can guide research and present these theories with the terms used by the authors. Amongst the 52 studies that explicitly or implicitly address gender theory, Social Role Theory (Eagly, 1987) is referred to most frequently (n = 19), followed by Thelwall's (2011) Social Web Gendered Privacy Model (n = 11) and Petronio's (2002) Communication Privacy Management Theory (n = 10).

Conclusions and implications. In our sample, explicit gender theorizing is scarce. We found that most studies build their rationale upon earlier empirical findings or make certain theoretical claims inherent to gender theories rather than explicitly building upon published and “ready-made” models or theories. In this sense, gender seems to be considered a helpful variable for explaining variance in privacy-related outcomes. This approach has the advantage of explaining variance in online privacy behavior and enriching privacy-related modeling by including a gender perspective. This approach fails, however, in providing large-scale and prospective ideas on how gender and privacy are related; it fails in generating ideas to intervene, change, contribute. If gender is reduced to a variable without theoretical context, a study will not be able to inform media literacy programs or ideas on privacy-by-design (Gregor, 2006, p. 616). We conclude that in online privacy research, gender is an undertheorized topic in relation to its tremendous social impact. However, scientific research can and should adequately take into account important societal categories such as gender and make an effort to include diverse perspectives “to ensure both equality and quality” (Trepte & Loths, 2020, p. 1).

*Data, supplemental tables and figures are available at the OSF Project ‘Theorizing Gender in Online Privacy Research’, cf. https://osf.io/4zwn9/?view_only=ec26ebfab5394b71ac275419e9e06e22. The data analysis is fully reproducible.