تفاوت های جنسیتی در خودارائه گری فیس بوک: یک مطالعه تصادفی بین المللی

Abstract Facebook is a popular social network that can be used for self-presentation. In the current study we examined gender differences in Facebook self-presentation by evaluating components of profile and cover photos. We used evolutionary psychology—a theory which holds many assumptions regarding gender differences—to draw hypotheses. In order to eliminate the pitfalls of self-reported data, we analyzed public data presented in Facebook pages of a random representative international sample of 500 Facebook users. As hypothesized, profile photos on Facebook differed according to gender. Males’ photos accentuated status (using objects or formal clothing) and risk taking (outdoor settings), while females’ photos accentuated familial relations (family photos) and emotional expression (eye contact, smile intensity and lack of sunglasses). Cover photos, however, did not show most of these gender differences, perhaps since they serve only as a supplement to the self-presentation that appears in the profile photos. These findings demonstrate that evolutionary theory rooted in the past can help us understand new social tools of the future.

. Introduction Social network sites (SNSs) such as Facebook, Twitter, and LinkedIn, have grown tremendously in recent years (“comScore,” 2011). Among these, Facebook has emerged as the most popular website (“Top sites,” 2013), with a reported one billion monthly active users, and 655 million daily active users (“Facebook,” 2013) uploading 350 million new photos every day (Henschen, 2013). These users present both explicit data of themselves (such as age, gender and marital status) and implicit data (such as photos or degree of disclosure). These data reflect the perceptions, attitudes and behaviors of the users, allowing us to study the psychological mechanisms underlying self-presentation. In this study we investigate gender differences in self-presentation by analyzing implicit data depicted in profile and cover photos. The results of such an investigation bear both theoretical and practical consequences. Theoretically, there is an on-going debate regarding the existence and magnitude of behavioral gender differences (for a recent review see Stewart-Williams & Thomas, 2013). Investigating these differences as they are depicted on Facebook may offer a new perspective, since Facebook users are culturally diverse and their behavior is more naturalistic than that of conventional samples. Practically, identifying gender differences in self-presentation can assist a number of professionals in making well-informed choices in their websites. Firms, for instance, can improve their employee photos. Marketers can improve the images of their endorsers. Online dating sites can advise their customers how to present themselves on the site. Finally, users of SNSs may improve their choice of profile photo for social and professional self-presentation (Brown & Vaughn, 2011). 1.1. Self-presentation in Facebook Self-presentation is one of the major motives driving activity in SNSs (Krämer & Winter, 2008). Facebook users can present themselves through explicit declarations, such as their interests or favorite music (Pempek, Yermolayeva, & Calvert, 2009), but they appear to rely more on implicit cues in posted photos (Zhao, Grasmuck, & Martin, 2008). When people evaluate the personality of a Facebook user, they base their impression mostly on the profile photo (Ivcevic & Ambady, 2012). Despite the salience of Facebook profile photos, however, there has been limited research on the topic. Profile photos have practical implications since their appeal can raise the response rate to friendship requests (Tifferet et al., 2012 and Wang et al., 2010). Lately, in addition to the profile photo, Facebook has first enabled and later required users to add a cover photo as part of the new Timeline format (Smith, 2012). These two photos allow the users to express and define themselves by projecting two similar or complementary images. 1.2. Gender differences in Facebook self-presentation While many studies explore gender differences in Facebook users (see Table 1), the data on self-presentation is lacking. In the only study we found that targeted gender differences in Facebook self-presentation, Hum et al. (2011), found no significant gender differences in the number of profile pictures, the level of activity in the photos, the appropriateness of the photos or the number of subjects in them. This gender similarity may have resulted from choosing explorative hypotheses that were not theory-based. For instance, Hum et al. (2011) compared how frequently men and women posted posed photos versus candid photos. Theoretically, there is reason to hypothesize that women may pose differently than men, emphasizing different features (Vigil, 2009), but there is no apparent reason to hypothesize that there would be differences in the frequency of posing. In the current paper, we propose a number of specific hypotheses based on evolutionary psychology, a field with a long-standing history of research on gender differences (e.g., Archer, 1996, Archer, 2004, Bjorklund and Kipp, 1996, Buss, 1989, Schmitt et al., 2003 and Wilson and Daly, 1985). Table 1. Studies assessing gender differences in Facebook users. Study Research method Main gender finding Acar (2008) Student Survey In comparison to men, women have more friends and spend more time on SNSs Bonds-Raacke and Raacke (2010) Student Survey In comparison to men, women have less friends and are more likely to set their account to private Fogel and Nehmad (2009) Student Survey Women disclose their phone number and address less than men Hargittai (2008) Student Survey No difference in frequency of Facebook usage Hum et al. (2011) Student photo analysis No difference in profile photos Kosinski et al. (2013) Analysis of Likes Based on their Likes, males and females were correctly classified in 93% of cases Lewis et al. (2008) Student network analysis No difference in network size McAndrew and Jeong (2012) International survey In comparison to men, women spend more time managing their photo impression and in dealing with family photos. Muscanell and Guadagno (2012) Student survey Women maintain relationships, men form new ones Park, Kee, and Valenzuela (2009) Student Survey Women use Facebook for information purposes more than men Pempek et al. (2009) Student Survey Women report having more friends than men Valenzuela, Park, and Kee (2009) Student Survey Women are more likely to have a Facebook profile Table options 1.3. Evolutionary view of gender differences Traditionally, gender differences in behavior have been attributed to cultural role expectations (e.g., Eagly, 1987). Evolutionary psychology views gender differences as rooted in genetic variations that arose millions of years ago through natural selection (Buss, 1995). According to evolutionary theory, men and women today have different behaviors since they had to deal with different challenges in the prehistoric past (especially in the fields of parenting and mating). For instance, in comparison to men, women take on a greater share of childcare in hunter-gatherer (Konner, 2005) and other traditional societies (Konner, 2010 and Whiting and Edwards, 1988). This suggests that a similar division of labor was present in our ancestral past, and that ancestral women may have adapted traits that were beneficial for childcare. One example is the trait of empathy. A few million years ago, a woman with low levels of empathy may have had less success in raising her children to adulthood, since she was less sensitive to their needs. This would have lowered her chances to hand down her genes to future generations, including the genes responsible for lower empathy. Since men at that time probably played a smaller role in childrearing than women, their lack of empathy may have been less detrimental to the chances to pass on their genes. In this fashion, natural selection sculpted unique behavioral profiles for men and women. This is not to say that all women have higher empathy levels than men—only that women in average have higher empathy levels than men (Baron-Cohen & Wheelwright, 2004). This also does not suggest that women are better than men, since every trait has tradeoffs, and maternal empathy, for instance, may have a price of increased anxiety and depression (Tifferet, Manor, Constantini, Friedman, & Elizur, 2011). The design of most studies in the field of gender differences does not allow researchers to determine whether the cause of the difference is social or evolutionary. In most cases both causes are in play—moreover, they interact (e.g., Schmitt, Realo, Voracek, & Allik, 2008). Over recent decades, social explanations for gender differences have increasingly been replaced by explanations that take an evolutionary approach (see for example Archer, 2004 and Schmitt et al., 2008). Even Eagly (Eagly and Wood, 2011 and Wood and Eagly, 2002) has moved to a more integrative biosocial model. In the field of cyberpsychology, however, the traditional social theory for gender differences still dominates (e.g., Dunn and Guadagno, 2011, Guadagno et al., 2011, Hum et al., 2011 and Muscanell and Guadagno, 2012) with very few studies using the evolutionary framework (e.g., McAndrew & Jeong, 2012). We now propose a number of gender differences in the self-presentation of Facebook users through their profile and cover photos, basing our hypotheses on evolutionary psychology. 1.3.1. Family relations In comparison to men, women are more orientated towards familial relations, and are considered the keepers of the family (Salmon & Daly, 1996). One explanation of this phenomenon is that evolution has shaped females to be the main caregiver, as is evident in both industrialized (Belsky et al., 1984 and Lamb et al., 1982) and non-industrialized (Whiting & Edwards, 1988) societies. In addition, women have a higher parental confidence than men (Trivers, 1972), which may strengthen their bond to the child (Geary, 2005). Kosinski, Stillwell, and Graepel (2013) predicted the gender of 58,000 volunteers by analyzing their Facebook Likes. ‘Proud to be a Mom’ was one of the top Likes that predicted a female gender, while none of the top Likes predicting a male gender was related to parenting. This suggests that parenting has a unique significance for females on Facebook. In another study, an open vocabulary analysis of the Facebook messages of 750,000 volunteers found that females used more words relating to family than did males (Schwartz et al., 2013). An online international survey of SNS behaviors found that women reported appearing in more family photos and spending more time looking at pages of relatives (McAndrew & Jeong, 2012). This difference may also represent itself in the choice of photos people present in their Facebook profile and cover photos. We therefore hypothesize that: H1. In comparison to adult women, adult men will post fewer family photos. 1.3.2. Status In comparison to men, women are more impressed by the social and economic status of their partner (Li, Bailey, Kenrick, & Linsenmeier, 2002). In ranking the most important traits of a spouse, women rank a good earning capacity significantly higher than men do (Buss & Barnes, 1986). This trend has also been documented in cross-cultural settings, such as an analysis of traditional folktales from 48 different cultures (Gottschall, Martin, Quish, & Rea, 2004). A study of two villages in Bolivia found that prestigious men were more likely to marry early, secure extra-marital relations and re-marry (Von Rueden, Gurven, & Kaplan, 2011). This tendency is not limited to the offline realm. An analysis of 600 internet personal ads showed that women sought status, and men displayed it (Alterovitz & Mendelsohn, 2009). It appears, therefore, that women are more concerned about their spouse’s status than men are. A high status signals both good genes and the potential to invest in the offspring (Geary, 2005, Griskevicius et al., 2007 and Sundie et al., 2011), and is therefore more important to females, whose parental investment is higher than that of males, and less malleable (Geary, 2005). The female preference for high-status males has been documented in many cultures (Bird and Smith, 2005 and Godoy et al., 2007) and in many non-human species (Gwynne, 2008 and Schaedelin and Taborsky, 2009), suggesting that cultural explanations may not suffice. Studying gender differences on Second Life, Guadagno et al. (2011) found that men were more likely than women to build and own objects. This is not surprising since one way of portraying status in modern society is by presenting status symbols such as cars (Belk, 2004) or fashion accessories (Han, Nunes, & Drèze, 2010). In mating situations men tend to increase their display of status symbols in order to increase their appeal to women (Griskevicius et al., 2007 and Janssens et al., 2011), and they tend to do so more than women (Griskevicius et al., 2007). Another way of signaling potential status is by displaying a unique skill or ambition, a trait that women tend to prefer in their partners (Buss, 1989 and Buss and Barnes, 1986). In one experiment, Tifferet et al. (2012) created two identical Facebook profiles of a man. The only difference between the two was that in one of the profiles the man was holding a guitar. The response rate of females was significantly higher for the man with the guitar, indicating that musical inclination makes a man more attractive. Since Facebook can be used for mating purposes (Tosun, 2012), we hypothesized that in order to portray status and skill: H2a. In comparison to females, males will post more photos with objects. Another way in which a man can signal his status is by wearing formal clothing, which can lead to a preference towards men in formal attire. For instance, one study showed that restaurant clients in business suits were served earlier, in comparison to men in casual dress, while no effect was documented for women’s dress (Stead & Zinkhan, 1986). Professors’ style of dress also interacts with gender, influencing how students perceive them. A formal dress style was associated with credibility in male, but not female professors, who were perceived as more credible when they dressed casually (Sebastian & Bristow, 2008). This preference towards men in suits may be especially strong for female appraisers. In deciding on which accountant to hire, women clients preferred photos of men and women in formal clothes, while men preferred those in casual attire (Chawla, Khan, & Cornell, 1992). This leads to the next hypothesis: H2b. In comparison to females, males will post more photos in which they wear formal clothes. 1.3.3. Risk A meta-analysis of 150 studies reported that males take more risks than females (Byrnes, Miller, & Schafer, 1999). Similar results have been reported in a review of economic experiments (Croson & Gneezy, 2009). A study on SNS users showed that men reported greater risk-taking attitudes and a higher likelihood of disclosing personal data such as phone number and home address (Fogel & Nehmad, 2009). Kosinski et al. (2013) predicted the gender of 58,000 volunteers by analyzing their Facebook Likes. Remarkably, all of the 10 top Likes that predicted a male gender were related to risk taking, while none of the Likes that predicted a female gender did. These Likes can be categorized into warfare (e.g., Modern Warfare 2, Band of Brothers, Deadliest warrior), sports (e.g., ESPN, X Games), and alcohol (Dos Equis). From an evolutionary perspective, risk aversion is likely to have been selected for in women: A cautious, risk-averse mother would have had better chances of protecting her children, and therefore passing on her genes to future generations. Ancestral men, on the other hand, would have benefited from risk taking, as they engaged in the competition for resources and mates (Wilson & Daly, 1985). This may explain the female attraction to men who take risks. For example, women are more likely to comply with requests from men wearing firefighter uniforms (Guéguen, 2009), perhaps due to their appeal as men who face danger. Risk orientation can be reflected by the involvement in outdoor activities, especially those considered extreme. This orientation is stronger for men than for women. Hirschman (2003), for example, described the American value of “rugged individualism” characterizing stiff men embarking in outdoor activities (such as hunting), with their dogs, guns, and cars. The well-known “Marlboro man” cigarette advertising character—riding his horse alone in the mountains of the mid-west—became a symbol of this risk-taking masculine image. Hence we predict: H3a. In comparison to females, males will post more outdoor photos. Risky tendencies can also be portrayed by consuming alcohol, smoking, and using illegal drugs (Kraemer, 2000). Indeed, students who posted Facebook photos of themselves drinking alcohol were more likely to consume alcohol (Glassman, 2012). There appears to be a gender difference in the portrayal of substance use. A study on MySpace users (a smaller SNS than Facebook) found that public photos and videos of drug use, like marijuana, often included a single male. Alcohol drinking, however, often included groups of females (Morgan, Snelson, & Elison-Bowers, 2010). Based on the masculine tendency towards risk taking, we hypothesize that: H3b. In comparison to females, males will post more photos with cigarettes or alcohol. 1.3.4. Emotional expression A meta-analysis of 58 studies shows that females have an advantage in facial emotional expression, from as early as infancy, and through childhood and adolescence (McClure, 2000). For instance, women tend to smile more than men do, especially in when they know they are being observed (LaFrance, Hecht, & Paluck, 2003). This expressivity of emotions, including smiling and initiating eye contact, may be an adaptation selected for strengthening mother–child attachment and communication (Konner, 2010). Indeed, maternal emotional sensitivity is related to better mother–child attachment (Bigelow et al., 2010). Emotional expressions may signal different traits in men and women (Vigil, 2009). In a study of mock interviews (Levine & Feldman, 2002), eye contact increased women’s likeability, but decreased men’s likeability. Perhaps eye contact signals sociability in women (making them more likeable) but signals dominance for men (making them less likeable). Emotional expressions also interact with gender to create an impression of high social status. Whereas women who display positive emotional expressions are rated of a higher social status; men who do so risk being rated as having low social status (Coats & Feldman, 1996). Again, these emotional cues may signal agreeableness in women, while signaling vulnerability in men. It is therefore reasonable that in a self-presentation context women would choose to present emotional expressions such as eye contact and smiling, while men would be less likely to do so. In the social media context, a large-scale study of Pinterest showed that women indeed tended to describe themselves using affectionate vocabulary, while men tended to use assertive vocabulary (Ottoni et al., 2013). Similar results were documented in a large-scale study of Facebook users showing that females use more words relating to affective processes and feelings than do males (Schwartz et al., 2013). Male Facebook users were more likely than females to report showing a serious expression in their profile photo (McAndrew & Jeong, 2012). Following these findings with regard to the presentation of emotional cues we predict that: H4a. In comparison to females, males will post more photos hiding facial cues (e.g., photos in which they are wearing sunglasses). H4b. In comparison to females, males will exhibit less eye contact in their photos than females. H4c. In comparison to females, males will exhibit less smiling in their photos. 1.4. Methodological rationale Almost all of the studies on Facebook gender differences use surveys in which participants in a convenience sample report their behavior on social networks (see Table 1). While this is a common method in the social sciences, it does have its downfalls. First, participants may not remember their network actions in the past (Brewer, 2000). Second, they may answer the survey in a socially desirable fashion (De Jong, Pieters, & Fox, 2010) rather than reporting accurately. Third, some interesting psychological behaviors are unconscious (e.g., Bargh and Morsella, 2008 and Dijksterhuis et al., 2005), so a man may display a photo of himself with a sports car in the background without being aware of the reason for doing so. Fifth, most samples were limited to an American college students (e.g., Bonds-Raacke and Raacke, 2010, Fogel and Nehmad, 2009, Hargittai, 2008, Hum et al., 2011, Muscanell and Guadagno, 2012, Park et al., 2009 and Pempek et al., 2009). These samples are highly biased, especially in light of the fact that 79% of Facebook users are from outside the U.S. and Canada (“Facebook 2013). It is not surprising that in a recent review of Facebook studies the authors concluded that, “In general, it will be important to diversify the methodologies in use in Facebook research, which, at present, rely very heavily on subjective accounts” ( Anderson, Fagan, Woodnutt, & Chamorro-Premuzic, 2012, p. 42). For these reasons, we refrained from self-report scales and relied on analyzing public data presented in Facebook pages of a random representative international sample of Facebook accounts.

Results 3.1. Gender differences We evaluated gender differences separately for profile photos and cover photos and also looked for differences in how people use profile and cover photos. Table 2 includes detailed results for each measured variable. Table 2. Gender differences in Facebook profile and cover photos. Photo characteristics Male N = 302 Female N = 198 Sample size χ2 (or U) M:F Ratio (or r) Profile photo H1: Families Families (%) 10 18 330 5.0⁎ 0.5 H2: Status Objects (%) 29 19 500 6.1⁎⁎ 1.7 Formal clothing (Mdn) 3 2 320 (8071⁎) (-.1) H3: Risk Outdoors (%) 36 24 420 6.8⁎⁎ 1.8 Drugs (%) 2 2 500 0 1.0 H4: Emotional expression Sunglasses (%) 13 5 320 6.0⁎ 3.0 Eye contact (%) 70 82 320 5.0⁎ 0.9 Smile intensity (Mdn) 0 1 320 (16392⁎⁎) (.4) Cover photo H1: Families Families (%) 12 34 130 9.0⁎⁎ 0.3 H2: Status Objects (%) 36 26 320 3.1 1.6 Formal clothing (Mdn) 2 3 90 (719) (.2) H3: Risk Outdoors (%) 41 40 190 0.0 1.1 Drugs (%) 4 3 320 0.3 1.4 H4: Emotional expression Sunglasses (%) 16 3 90 3.2 5.7 Eye contact (%) 60 52 90 0.6 1.4 Smile intensity (Mdn) 0 0 90 (855) (.1) Note. Chi-square tests were used to analyze families, objects, outdoor activity, drugs, sunglasses, and eye contact. Mann–Whitney U tests were used to analyze ordinal variables: formal clothing (0 = minimal, 1 = sportive, 2 = casual, 3 = smart, 4 = formal) and smile intensity (0 = no smile, 1 = smile with no teeth showing, 2 = smile with teeth showing). Mdn = Median. M:F = Male:female. Values of r were calculated based on male = 0. ⁎ p < .05. ⁎⁎ p < .01. Table options 3.1.1. Gender differences in profile photo characteristics As hypothesized, profile photos on Facebook differed according to gender. Males’ photos accentuated status (using objects or formal clothing) and risk taking (outdoor settings), while females’ photos accentuated familial relations (family photos) and emotional expression (eye contact, smile intensity and lack of sunglasses). One exception was that there was no significant gender difference in the portrayal of alcohol and cigarettes in the profile photos. This, however, may have resulted from the small overall number of profile photos displaying drugs (10/500). 3.1.2. Gender differences in cover photo characteristics Contrary to our hypotheses, there were hardly any gender differences in the cover photos. The only clear difference was that women had a higher chance of displaying family photos than men. Other than that, there were no statistically significant differences in the display of status (using objects or formal clothing), risk taking (outdoor settings or drugs), and emotional expression (eye contact, smile intensity and lack of sunglasses). 3.1.3. Gender differences in Facebook usage Aside from the study hypotheses, we checked for descriptive gender differences in Facebook usage. It appeared that there were no differences in the number of Friends (t(399) = 0.40, p = .69) or the number of Likes (t(243) = −1.63, p = .10) between male and female profiles. Females, however, were more likely to post a cover photo in the new timeline format (χ2(1, N = 500) = 8.47, p = .004, male to female Odds Ratio = 0.6). Next, we checked for gender differences in disclosure of personal information on public Facebook pages. There was no difference in the disclosure of the relationship status (χ2(1, N = 500) = 1.10, p = .29), the number of Friends (χ2(1, N = 500) = 0.08, p = .78), the year of birth (χ2(1, N = 500) = 3.05, p = .08, male to female OR = 1.9) or Likes (χ2(1, N = 500) = 3.10, p = .08, male to female OR = 1.5). 3.2. Differences between profile and cover photos McNemar tests for paired data showed that while Facebook users often used their profile photo to show their own picture, they were likely to use their cover photo to convey additional data. Eighty-five percent of the profile photos had at least one human in them, in comparison to only 60% of the cover photos (χ2(1, N = 319) = 49, p < .001). Sixty percent of the human profile photos showed one adult whose gender was congruent with that mentioned in the profile (suggesting a self-photo), in comparison to 31% of the cover photos (χ2(1, N = 149) = 23, p < .001). Cover photos, however, included a higher percentage of family photos (21% vs. 13%; χ2(1, N = 94) = 4, p = .04) and outdoor photos (57% vs. 48%; χ2(1, N = 87) = 4, p = .04).