Abstract
The prevalence of a negative body image among women is high. Because of its serious consequences for individuals’ mental health, there is an urgent need to improve current body image interventions. Recent studies using evaluative conditioning to strengthen the association between women’s body and positive (social) stimuli have shown promising results. In two experimental studies, we tested whether incorporating more age appropriate positive social stimuli as unconditioned stimuli (USs) can strengthen the conditioning procedure as a means to enhance women’s body satisfaction. In the experimental condition, participants’ body pictures were systematically followed by the Facebook like-button and youthful smiling faces (study 1, experimental condition:
Introduction
Over the last decades, Western media have been persistent in their celebration of the ultra-thin female body (e.g., Katzmarzyk & Davis, 2001; Seifert, 2005; Wiseman et al., 1992), yet over that same period, the average body weight of women has increased considerably (Abarca-Gómez et al., 2017; NCD Risk Factor Collaboration, 2016). As the idealized thin body type is not representative of the average female body and (genetically) unattainable for many, it is not surprising that body dissatisfaction is nowadays prevalent among women (e.g., Fallon et al., 2014; Tiggemann, 2004). The high prevalence of body dissatisfaction is particularly problematic because a negative body image (NBI) is considered a key component in the development, maintenance, and relapse of eating disorders (Carter et al., 2004; Stice & Shaw, 2002). The cognitive behavioral model of eating disorders (Fairburn et al., 1999) proposes that eating disordered individuals base their self-worth almost entirely on how they evaluate their body shape and weight. These evaluations are thus an important target for intervention. However, a meta-analysis by Alleva et al. (2015) showed that once corrections for several sources of bias were applied, current stand-alone body image interventions only led to small improvements. Thus, there is an urgent need to further advance NBI treatments.
In this study, we tested a relatively new technique for improving body image in which the principles of evaluative conditioning are used to enhance positive body evaluations. Evaluative conditioning (EC) is a procedure for changing the liking of a stimulus by systematically pairing that stimulus (i.e., the conditioned stimulus; CS) with a positive or negative unconditioned stimulus (US). As a consequence, the valence of the CS changes in the direction of the valence of the US (e.g., De Houwer et al., 2001). Due to the pervasiveness of women’s negative beliefs about their bodies, this implicit approach may be more effective than interventions that challenge women’s NBI in a more direct manner (Martijn et al., 2015). Martijn and colleagues (2010) were the first to test if indeed individuals’ body image could be improved by a brief computerized EC procedure during which own-body pictures (CS+) were systematically followed by smiling faces as positive USs, and pictures of two healthy-weight control bodies (CS−) were followed by neutral and frowning faces. Smiling faces were selected as positive US because they signal social acceptance. Since sociocultural pressures and direct social influences (e.g., negative feedback or teasing) are among the most important determinants of body dissatisfaction (Littleton & Ollendick, 2003; Stice, 2002), others’ approval of the own body was expected to have a large effect on women’s body evaluations. In the control condition, the own body and control bodies were equally often followed by smiling, neutral, and frowning faces. After a single session of this EC procedure, women in the experimental condition (
Subsequent research that used relatively similar EC procedures were, however, not successful in replicating these promising findings. In a clinical sample of healthy weight adolescent girls with an eating disorder (
The aim of this study was to strengthen the EC procedure of Martijn and colleagues (2010) by tackling three limitations of the original procedure that can have weakened positive EC effects on body satisfaction. First, the facial USs were potentially a bit outdated as signs of body approval, considering young women rely heavily on social media for reassurance about their appearance (e.g., Haferkamp et al., 2012; Perloff, 2014). The majority of the facial USs also looked too old to pass for undergraduate students, which may have reduced their relevance as a positive US, because young women primarily desire social approval from peers (Harter et al., 1996; Mota & Matos, 2013; Rubin et al., 2007; Thomaes et al., 2010). Second, the original EC procedure exposed body concerned women to control bodies, and comparison making to these bodies will probably negatively influence satisfaction with the own appearance (Newton & Minhas, 2005). Finally, the salience of CS+ trials might have been suboptimal in previous research. Decreasing the predictability of the occurrence of a CS+ trial (e.g., by increasing the number of CS− trials), might promote contingency learning because it renders the CS+-US pairings more salient.
We therefore developed a modified EC procedure in which women’s own-body pictures (CS+) were systematically followed by a youthful smiling face (50%) or Facebook like-button (50%) as positive USs, whereas neutral body-unrelated control pictures (CS− trials) were followed by a blank screen. The CS+ was presented only in 25% of the trials to heighten the saliency of the CS+-US pairings. Finally, we used a control condition in which the CS+ and CS− were never followed by a negative or positive outcome, but always by a blank screen. Previous research has shown that individuals with body concerns tend to overestimate the contingency between pictures of their body and negative outcomes (covariation bias; see Alleva et al., 2014; Glashouwer et al., 2019), 1 and the control condition of Martijn et al. (2010) might have unintentionally (and undesirably) reduced participants’ body satisfaction due to this overestimation of negative USs. To prevent the stimulus configuration from artificially increasing the contrast between the experimental and control condition, we thus removed the USs from the control procedure.
Given the novelty of the current approach, we decided to first conduct a proof-of-principle study and test the modified EC procedure in a female sample that was not specifically selected on the basis of body image concerns (cf. Glashouwer et al., 2019; Martijn et al., 2010). Using the modified EC and control procedure, we tested the hypotheses that women in the experimental condition would (i) evaluate their own body pictures more positively and (ii) report higher levels of body satisfaction after the procedure than women in the control condition. In addition, we tested whether in line with Martijn et al. (2010) the anticipated EC effects would be most pronounced in women with relatively high body concern.
Study 1
Method
Participants
In total, 138 women (
Materials
Stimuli
CSs+ were three photographs that were taken from the front, left, and right side of the participant. Participants were photographed in front of a white background, while they held their arms next to their body and posed with a neutral facial expression. All participants wore a pink short-sleeved T-shirt and black sports legging. Photographs were taken with a Panasonic DC-FZ82 camera and cropped to 352 (width) × 452 (length) pixels.
As neutral pictures (CSs−), we used 90 pictures (352 × 452 pixels) from the International Affective Picture System (Lang et al., 1997). The USs consisted of one image of an upward thumb with the word “Like” next to it (cf. Facebook’s like-button; 266 × 140 pixels) and 45 youthful smiling facial stimuli (352 × 452 pixels) that were derived from the 3rd version of the Face Research Lab London Set (DeBruine & Jones, 2017) and the Max Planck FACES Database (Ebner et al., 2010). See the appendix for a detailed description of the selection procedure.
Evaluative conditioning procedure
The evaluative conditioning procedure was programmed with E-prime 2.0 software (Psychology Software Tools, Pittsburgh, PA). Participants were informed that a stimulus would randomly appear at the center of one of four quadrants, and instructed to click on each appearing stimulus as fast as possible. After participants clicked on a CS+ (90 trials), a facial US (45 trials) or the social media US (45 trials) appeared for 400 milliseconds. When participants clicked on a CS− (270 trials), it disappeared and the next trial started after 400 milliseconds (see Figure 1). The order of stimulus presentation was random. When participants in the control condition clicked on a CS+ or CS−, the stimulus disappeared and the next trial started after 400 milliseconds (similar to the CS− trials in the experimental condition). Examples of trials in the evaluative conditioning procedure. After a participant clicked on the full-body picture (CS+), a smiling facial US appeared at the same location (a) or the social media US appeared in the right bottom corner of the picture (b). The US disappeared after 400 ms. After a participant clicked on a neutral control picture (CS−), it disappeared and the quadrants were empty until the next trial started after 400 ms (c).
Measures
Stimulus valence
The body pictures (CS+) were rated on valence (0 =
Body satisfaction
Post-intervention body satisfaction was assessed with two VAS scales (“
The Body Image States Scales (BISS; Cash et al., 2002) were used as a secondary outcome measure of state body image. The BISS consists of 6 items that measure participants’ satisfaction with aspects of the physical appearance on a 9-point Likert scale (1 =
Body concern
The 6th version of the Eating Disorder Examination Questionnaire (EDE-Q; Fairburn & Beglin, 2008) was administered as a measure of participants’ body concern. The EDE-Q measures self-reported body concerns and eating disorder pathology in the last 28 days. Its 28 items are answered on a 7-point Likert scale (0 =
Procedure
The study was advertised as a study about the influence of exposure to selfies on feelings of happiness. Participants were tested individually, in a single 1-hour session. Each participant actively gave informed consent at the start of the test session. The researcher estimated participants’ clothing size and provided the participant with the standardized clothing (size labels were covered). After the photoshoot, participants completed the EDE-Q on the computer (1920 × 1080 IIYAMA, refresh rate = 60 Hz). Next, participants were randomly assigned to the experimental or control condition, and executed the EC procedure. Participants then completed the life satisfaction questionnaire and the BISS. For comparability to prior study procedures, the Rosenberg Self-Esteem Scale (RSES; Rosenberg, 1965) was administered after the EDE-Q and the State Self-Esteem Scale (SSES; Heatherton & Polivy, 1991) after the BISS. 2 Next, participants rated the valence of the stimuli from the EC procedure and completed demographic questions and questions about the presumed purpose of the study. Finally, participants’ weight (with clothing) and length were measured.
Statistical analyses
The effect of the EC procedure on the primary outcome measures was tested using three stepwise hierarchical regression analyses with CS+ valence, CS+ attractiveness, or VAS body satisfaction as dependent variable. Condition (Control, Experimental), Body concern, and the interaction of Condition × Body concern were entered in the model in a first, second, and third step, respectively. The first step was essential to test if the EC procedure improved the evaluation of the CS+ and heightened body satisfaction. The hypothesis that women with higher body concern profit more from the EC procedure was tested in the third step. A similar stepwise hierarchical regression analysis was performed with BISS scores (i.e., the secondary outcome measure) as dependent variable. For the primary analyses, alpha criterion was set to .0167 (
Power calculation
A priori power calculation indicated that a sample size of 99 participants was required to obtain a power of .80 to detect a medium effect (
Results and discussion
Descriptives
Means and standard deviations for group characteristics in studies 1 and 2.
Means and standard deviations for the evaluation of the USs in studies 1 and 2.
Primary and secondary outcome measures
Means and standard deviations for outcome measures in studies 1 and 2.
Discussion
After the EC procedure, women in the experimental condition did not evaluate the own-body pictures more positively, nor did they report more body satisfaction or state body image than women in the control condition. Also, body concerned women did not profit more from the EC procedure than women with relatively low body concern. These results indicate that the modified EC procedure failed to manipulate body satisfaction at a fundamental level, namely, the EC procedure did not improve the affective appreciation of the CS+. Post-manipulation valence ratings of the CSs+ indicated that on average, participants rated their body pictures close to neutral (
One reason for the weak positive valence of the social media US could be that the Facebook like-button was perceived as being a bit outdated. Young women tend to use newer social media which use other buttons to like something (e.g., Instagram’s heart icon; Auxier & Anderson, 2021). An alternative reason that would also explain the moderate appreciation of the facial USs could be that the removal of neutral and negative USs from the current design diminished the reward value of the positive USs that followed the CSs+. Contrasting positive feedback on the own body with the neutral and negative feedback on the control bodies, could increase the rewarding properties of the positive feedback by underscoring that the social acceptance signaled by the USs is specific to the own body. Perhaps the positive effect of including control bodies as CSs− might actually outweigh the cost of undesirable upward comparison processes. After all, in our prior study (Glashouwer et al., 2019) the control bodies were (on average) rated as more attractive than the own body, yet body concerned participants did report a more positive appreciation of the own-body pictures after the EC procedure.
Therefore, we carried out a second study in which we went back to the original EC procedure of Martijn and colleagues (2010) and only adjusted the age appropriateness of the positive USs by replacing the facial stimuli with signs of social media approval. This time, we used Emojis as USs instead of the Facebook like-button. Given that all major social media platforms allow the use of Emojis, positive Emojis may have a stronger impact as a sign of approval than the like-button, especially for women who use other social media than Facebook. In the new EC procedure, participants’ body pictures (CSs+, 90 trials) were systematically followed by positive Emojis, whereas the control bodies (CSs−, 180 trials) were followed by neutral and negative Emojis (see Figure 2). In the control condition, the own-body pictures and control body pictures were followed by an equal amount of positive, neutral, and negative Emojis. The USs were again presented for 400 milliseconds. To determine the effectiveness of the EC procedure with positive Emojis, we used the same outcome measures and tested the same hypotheses as in study 1. Examples of a trial from the Evaluative Conditioning Procedure. After a participant clicked on the full-body picture (CS+), a positive US appeared for 400 ms at the same location (a). After a participant clicked on a control body (CS−), a neutral (b) or negative (c), US appeared for 400 ms (the depicted USs differ slightly from the ones that were used; the original stimuli can be obtained via the first author).
Study 2
Method
Participants
The sample consisted of 133 women (
Stimuli
The only difference with the CSs+ from study 1 is that the pictures were smaller (226 × 301 pixels) and that participants’ T-shirt color was counterbalanced (cf. Martijn et al., 2010). The CSs− (i.e., three full-body pictures of two control women) were previously used by Glashouwer et al. (2019). As USs, 18 WhatsApp Emojis were used (303 × 301 pixels). Emojis were derived from the Internet and based on the valence ratings in a pilot study of 39 women below the age of 30 years old (
Measures
The measures that were used were identical to those of study 1. Consistent with study 1, the body satisfaction items were highly correlated (Spearman’s rho:
Procedure
The study procedure was similar to that of study 1, with three exceptions. The CSs− were rated on valence and attractiveness (so not only valence), and for the USs the estimated evaluation question was rephrased to “How would someone think of you if he/she comments this Emoji on a picture of you?” (0 =
Statistical analyses
To test if the EC procedure improved participants’ evaluation of their own body (pictures), four identical stepwise hierarchical regression analyses as in study 1 were performed with CS+ valence, CS+ attractiveness, body satisfaction, or state body image (secondary outcome measure) as the dependent variable. Our predictions were consistent with study 1, and the alpha criterion was again set at .0167.
Results and discussion
Descriptives
Table 1 presents the means and standard deviations of the characteristics for each condition of study 2. The mean level of global self-esteem was comparable to the previous study and that of Martijn et al. (2010), whereas the mean level of body concern and eating pathology were a bit higher. The RTs during the EC procedure indicated that the participants again had executed the task conscientiously (RT:
Primary and secondary outcome measures
See Table 3 for an overview of the means and standard deviations of the outcome measures across conditions. Results of the hierarchical regression analyses indicated that contrary to expectations, Condition did not significantly predict CS+ valence (
Discussion
In study 2, we attempted to improve the EC procedure of Martijn et al. (2010) by selecting influential signs of social media approval (Emojis) as positive USs. However, in line with the results of study 1, we did not find an effect of the modified EC procedure on the satisfaction with the body (pictures) in the total sample nor in women with high body concern. This is somewhat surprising given that participants’ ratings indicated that the Emojis had a strong positive valence (
There are two limitations of study 2 which might have hampered the effectiveness of the current EC procedure. First of all, women in the experimental condition evaluated the control body pictures more positively than women in the control condition,
4
and as a result, they may have made more upward comparisons to the control bodies. The negative effect of these comparisons can have undermined the positive effect of the EC procedure. Without a baseline measure of CSs− valence, it is unclear whether the difference between the conditions existed before the manipulation or whether it reflects an effect of the manipulation. The latter would be difficult to explain in terms of EC because the CSs− were in the experimental condition more often paired with negative USs. Second, participants rated five out of six “neutral” Emojis as positive (
General discussion
In the present studies, we attempted to improve a procedure for improving a NBI based on the principles of EC (Martijn et al., 2010) that previously led to promising yet inconsistent results. To enhance the effect of the EC procedure on women’s body satisfaction, age appropriate signals of social approval were incorporated as positive USs. However, neither the procedure with youthful smiling faces and Facebook’s like-button (study 1) nor the procedure with Emojis as USs (study 2) resulted in a more favorable evaluation of the body pictures, or in higher body satisfaction. Although body concerned women had more room for improvement with regard to the appreciation of their body (pictures), they did not profit more from the EC procedures than women with low levels of body concern. Thus, incorporation of age appropriate USs appeared ineffective in improving the EC procedure.
Given the novelty of social media, there is presently not much research available that can help with understanding participants’ responses to affective social media stimuli. There is some preliminary empirical evidence from EEG studies, however, that suggests that positive Emojis are not as inherently rewarding (Weiß et al., 2020) and salient as smiling facial stimuli (Gantiva et al., 2020). Emojis generally depict an exaggerated sentiment, so they may be perceived as less sincere social cues and are, therefore, more likely discarded as signals of social approval. Observations in the lab also raised the suspicion that a substantial proportion of the participants had an unfavorable opinion about social media, which may have been an unwanted effect of how studies 1 and 2 were advertised (i.e., as a study on the influence of selfies on happiness). The finding that the valence of the Facebook like-button used in study 1 was not as positive as anticipated, fits with this idea. Since we did not measure participants’ opinion and use of social media, it cannot be ruled out that we unintentionally attracted women with negative opinions of social media. This could have negatively influenced the appreciation of the USs and thereby the efficacy of the current EC procedures.
Another limitation is that we did not include baseline measurements of women’s satisfaction with the body (pictures). To prevent body dissatisfied individuals from dropping out in between test sessions (e.g., due to the discomfort of being photographed), we decided to test participants in a single session. Measuring body satisfaction just before the manipulation could have made participants aware of our hypotheses and may have resulted in socially desirable responding. Although participants were randomly assigned to the conditions, it is still possible that women in the experimental condition were more body dissatisfied at baseline than women in the control condition. If so, the present results underestimate the effect of the EC procedures.
A completely different explanation for why the current EC procedures did not work is that the not-neutral valence of the body pictures of women with a NBI may have interfered with the induction of body-positive associations. Neutralizing an affective response (i.e., counter-conditioning; see Keller et al., 2020) may require a different approach than using EC to induce an affective response for initially neutral stimuli. Keller and colleagues (2020) argue that during the inhibition of a negative/aversive response by a positive/appetitive response, it is imperative that the induced positive response is stronger than the unwanted negative response. An issue with using EC as a procedure to improve participants’ NBI is that the body (CS+) likely elicits a stronger affective response than the smiling faces (US). Consequently, the CS+-US pairing may be associated with the negative affect elicited by the body and not the positive affect elicited by the smiling face.
On the one hand, this problem can be solved by masking techniques that minimize participants’ aversive reaction to seeing pictures of the own body (cf. Siegel et al., 2017). Without the interference of implicit and explicit body-evaluative processes, there may be enough leeway for novel implicit body-positive associations to form. On the other hand, this issue can be addressed by selecting USs that match the intensity of the negative affect elicited by the body pictures of women with a NBI. Given that social media stimuli can be interpreted as social signals and as references to the concept of social media, the affective appreciation of these stimuli may be stronger influenced by interpersonal and contextual factors than is the case for smiling facial stimuli. Smiling faces may therefore be more appropriate as USs, and there is research that suggests that smiles involving lip-pressing are particularly equipped to convey social affiliation (Rychlowska et al., 2017). Furthermore, virtual-reality can be used to make the social approval cues more rewarding by increasing their ecological validity (e.g., an avatar that starts smiling upon noticing the participant). The rewarding properties of the USs may be further increased by contrasting the approval of the own body with the disapproval of control bodies, although more research is necessary because exposure to control bodies can also have a negative effect on women’s body satisfaction. If proven effective, the dose of EC can be increased to see if this leads to stronger generalization to other measures of body satisfaction. More diverse CSs+ (e.g., the participant in different outfits or several body-focused environments) may also aid the generalization of EC effects. Thus, although it remains unclear if EC can be used to improve the body satisfaction, there are several alternative procedural improvements that seem worth investigating.
Conclusions
The present studies provided no evidence for the effectiveness of EC as a technique to improve women’s body image. Despite our efforts to strengthen the EC procedure developed by Martijn et al. (2010), the modified EC procedures did not improve women’s evaluation of the own-body pictures nor did they enhance self-reported body satisfaction. The results of study 2 demonstrate that even when the women’s body pictures are conditioned with USs that are very positively evaluated, this does not guarantee transfer of the USs’ positive valence to the body. Thus, the EC procedure in its current form is not ready for being applied as a NBI intervention technique.
Footnotes
Acknowledgments
The authors would like to thank Carolien Martijn for sharing the original materials; Elise van der Laan and Anne Jet Kloosterman for helping with the data collection; and the students who volunteered to participate in these studies.
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was supported by a Veni grant [451-15-026] that was awarded to the third author by the Netherlands Organization for Scientific Research. The funding source was not involved in the design of these studies nor in the production of this manuscript.
CRediT authorship contribution statement
Irina Masselman: conceptualization, methodology, software, formal analysis, investigation, and writing—original draft; Klaske Glashouwer: conceptualization, methodology, resources, writing—review and editing, supervision, project administration, and funding acquisition; and Peter de Jong: conceptualization, methodology, writing—review and editing, and supervision.
Pre-registration
The present studies were preregistered. To view the preregistration forms, go to https://aspredicted.org/h3v85.pdf (study 1) and
(study 2).
Data
Notes
Appendix
The following IAPS pictures were used as neutral control stimuli*: 1121, 1313, 1390, 1616, 1670, 1935, 1947, 2870, 5120, 5130, 5390, 5395, 5500, 5510, 5520, 5530, 5531, 5532, 5533, 5534, 5535, 5661, 5731, 5740, 5900, 5920, 6150, 6930, 7000, 7004, 7006, 7009, 7010, 7025, 7030, 7034, 7035, 7036, 7037, 7039, 7040, 7041, 7050, 7060, 7080, 7090, 7095, 7096, 7100, 7110, 7130, 7140, 7150, 7160, 7161, 7170, 7179, 7180, 7182, 7183, 7184, 7185, 7186, 7187, 7190, 7205, 7207, 7211, 7217, 7224, 7233, 7235, 7236, 7237, 7490, 7491, 7495, 7500, 7504, 7560, 7590, 7595, 7620, 7705, 7710, 7820, 7830, 7920, 8211, and 8311. IAPS picture 1935 was cropped to remove a spider, and IAPS pictures 1935, 2870, 7620, 8211, and 8311 were cropped to remove a body in the periphery of the picture.
The following facial stimuli were used**: Max Planck FACES Database, 020_y_f_h_b, 028_y_f_h_b, 048_y_f_h_b, 090_y_f_h_b, 101_y_f_h_b, 106_y_f_h_b, 115_y_f_h_b, 150_y_f_h_b, 152_y_f_h_a, 182_y_f_h_a, 013_y_m_h_b, 016_y_m_h_b, 057_y_m_h_b, 062_y_m_h_b, 066_y_m_h_b, 072_y_m_h_b, 089_y_m_h_a, 114_y_m_h_a, 119_y_m_h_b, 123_y_m_h_b, 127_y_m_h_b, 147_y_m_h_b, 153_y_m_h_b, 167_y_m_h_b; Face Research Lab London Set, 009_08, 013_08, 014_08, 030_08, 032_08, 064_08, 094_08, 097_08, 099_08, 100_08, 127_08, 129_08, 134_08, 004_08, 022_08, 026_08, 031_08, 036_08, 104_08, 117_08, 172_08. * Using the valence norms of the IAPS, we identified the 90 pictures that were considered most neutral and that were not centered on a human body or food item (Lang et al., 2008).
** From the Face Research Lab London Set, we selected 8 male and 13 female faces (Age:
