Edited by: Carolyn Yoon, University of Michigan, United States
Reviewed by: Honghong Tang, Beijing Normal University, China; Steven Bellman, University of South Australia, Australia
This article was submitted to Decision Neuroscience, a section of the journal Frontiers in Neuroscience
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In advertising studies, the impact of sexually appealing advertisements (hereafter “ads”) on consumers’ product preferences is highly controversial. This paper explores (1) how such ads affect consumers’ product preferences at the gazing stage (initial stage of exposure to the ad) and evaluation stage (final product preference), and (2) which type of product (utilitarian vs. hedonic) is more suited to such ads. We used an electroencephalogram to record participants’ product preferences at the gazing stage and self-reported product preferences at the evaluation stage. The results indicated that participants preferred ads with high sex appeal at the gazing stage and ads with low sex appeal at the evaluation stage. Further, compared to utilitarian products, hedonic products were more suited to sexually appealing ads. The findings suggest that the effect of such ads on consumers’ product preferences varies depending on their cognitive stage and the type of product advertised.
Shopping is a necessary part of daily life, and advertising is a common way to advocate products. Instantly capturing consumers’ attention is key to achieving high sales figures. The use of sex appeal in advertising is a common marketing strategy to attract consumers and promote awareness of the product.
Sexually appealing advertisements (hereafter “ads”) promote products using erotic images or sexual words. For example, the pun of “old driver” has two meanings in China. One denotes a driver who has been driving for many years, the other denotes a person who often tells sexual stories or dirty jokes. Owing to the particularity of “sex,” the use of sex appeal in advertising has been highly controversial. On the one hand, it can attract consumers’ attention to products. On the other hand, because of moral factors, people might reject such ads. Therefore, the effect of sex appeal in advertising has been a focus in the advertising literature, and the findings have been rather inconsistent (e.g.,
Two factors may reconcile this controversy. One is the difference between the initial and final stages of product preference. In prior studies, participants’ product preference was measured in an exposed environment. For example,
The other factor is the type of product (utilitarian vs. hedonic). Utilitarian products have effective, useful, functional, necessary, and practical attributes (e.g., a wrench or spoon). Hedonic products have interesting, exciting, thrilling, and enjoyable attributes (e.g., chocolate or perfume) (
This paper investigates (1) how sexually appealing ads influence consumers’ product preferences in the initial stage of being exposed to the ads and the final evaluation stage and (2) which type of product (utilitarian vs. hedonic) is more suited to such ads.
In this paper, we used electroencephalography (EEG) to measure initial preference for sexually appealing ads. EEG is an electrophysiological monitoring method that records electrical activity in the brain. It analyzes the changes in people’s brains through event-related potentials (ERP) or spectral content. It can record changes in the brain after a stimulus is presented in real time. Its high temporal resolution can detect people’s brain responses to stimuli in the early, middle, and later stages. The EEG data were used to infer initial preferences for sexually appealing ads. EEG has many applications in advertising research (
This paper also used the late frontal slow wave (LFSW), which is related to processing cognitive conflict. Studies have shown significant differences in the LFSW between conflict and non-conflict conditions when people process self-preference and social preference (
In addition to analyzing ERP components in EEGs, we also analyzed the brain network. Based on the spatiotemporal organization theory of brain activity (
In this paper, we used EEG and behavioral reports to record participants’ brain and behavioral responses (e.g., N200 in the initial stage, LFSW and subjective product preference in the final stage) to products with sexually appealing ads. We also examined which type of products (utilitarian vs. hedonic) were more suited to such ads.
A total of 25 healthy volunteers participated in this experiment. Data from four subjects were excluded because of errors in the recording of the EEG data. As a result, a total of 21 volunteers were fully analyzed (6 males, 15 females; mean age = 21.19 years ± 2.60). All participants were right-handed with no visual problems and no history of neurological diseases or mental disorders. All participants provided written informed consent prior to the experiment. The study protocol was approved by the Local Ethics Committee of Zhejiang University of Technology. This experiment was a two (sex appeal: high vs. low) × two (product type: utilitarian vs. hedonic) within-participants design.
High and low sex appeal pictures were selected from the study by
In this experiment, 34 product images were selected for evaluation. The participants were provided with information on the difference between hedonic and utilitarian products in the following way:
Examples of experimental materials.
Type | Example | Example | Example | Example |
Utilitarian products | ||||
Hedonic products |
Based on the experimental tasks of
The experiment was conducted in a soundproof room where the participants sat in front of a computer screen and put on an EEG electrode cap. They were asked to minimize their movements during the EEG experiment. The display of the stimuli and the acquisition of behavioral data were conducted using E-Prime software. All ad images were randomly presented on a standard computer screen. Only one ad image was presented in each trial. The participants were instructed to think about their preference for the ad. During the experiment, they were not required to make any substantive choices or other behavioral responses.
Experimental design.
For example, after a second of fixation, a high sex appeal hedonic ad was presented for 2.5 s. The participant was instructed to think how much he/she preferred the ad shown. After 28 trials, a picture of volleyballs was presented for 2.5 s. The participant was then asked to answer how many volleyballs were on the screen. At the end of the block, he/she could continue the task when ready by pressing the mouse button.
At the end of the EEG measurement stage, the EEG electrode cap was removed, and the participant commenced the behavioral task after 10 min of rest.
The EEG was taken from 64 scalp locations by electrodes mounted on an elastic cap with online reference to the left mastoid. The horizontal electrooculogram was recorded by two electrodes placed laterally on either side of the left and right eyes. The vertical electrooculogram was recorded by two electrodes located above and below the right eye. All electrode impedances were kept below 5 KΩ. All signals were sampled at 500 Hz, and the band-pass filtered frequency range was 0.01–100 Hz.
During the offline analysis, all EEG data were re-referenced to the mean of the left and right mastoids. A 20–Hz (24 dB/oct) low-pass filter was applied to all EEG data. The ocular artifacts in the data were removed via a regression procedure using Neuroscan software. Trials containing EEG sweeps with amplitudes exceeding ±80 μV were excluded. EEG data with a continuous duration of 1000 ms were extracted from each stimulus datum, including a 200 ms pre-stimulus period used as baseline.
In this experiment, the ERP components were analyzed using repeated-measures analysis of variance (ANOVA) in which sex appeal (high sex appeal vs. low sex appeal) and product type (hedonic vs. utilitarian) were used as within-participant factors. The time window of the frontal N200 component selected was 170–270 ms after stimulus presentation as peak amplitude, and the electrode selected was the fz electrode. The selection of the electrode and component time window was based on previous articles and visual inspection of the ERP grand average waveforms.
The standard PLI quantifies the phase synchronization of two different time series by detecting non-zero phase difference coupling. The weighted phase lag index (wPLI) extends the PLI by increasing the phase difference between two time series (
Based on the brain network connection matrix, we used the network’s small-world index as an analysis index to explore the differences under each condition. The small-world attribute is equal to the clustering coefficient/characteristic path length of the network. Therefore, the clustering coefficient and shortest path length are the two most important parameters used to describe and characterize the small-world topology of a network.
The clustering coefficient reflects the local integration capability of a network. The clustering coefficient indicates the possibility that the neighbors of a certain node are neighbors to each other. The value of the clustering coefficient C
In this paper, we used the average clustering coefficient of all nodes as the clustering coefficient of the network (
In this experiment, the method of calculating the “small-worldness” property was based on
All data were analyzed using SPSS 21.0, and the significance level was set at 0.05. The Bonferroni method was used to correct the
Inspired by
Experimental results.
Moreover, we also found an interaction between the level of sex appeal and product type:
Since the LFSW is a late prefrontal slow wave, the FP1 and FP2 electrodes of the prefrontal lobe were selected as the left and right frontal lobe electrodes for analysis based on previous studies (e.g.,
We selected the “small-worldness” property developed by
Delta band (δ: 0.1–4 Hz): The results revealed that the main effect for the product type was significant [
Theta band (θ: 4.1–8 Hz): The results revealed that the main effect for the product type was significant [
Alpha band (α: 8.1–12 Hz): The results revealed that there was no significant main effect for product type [
Beta band (β: 12.1–30 Hz): The results revealed that the main effect for the product type was significant [
A two (sex appeal) × two (product type) repeated measurement ANOVA on ad preference was conducted. The results revealed that the main effect of sex appeal was significant
The interaction between sex appeal and product type was marginally significant [
This paper explored the effects of sexually appealing ads on utilitarian and hedonic product preferences. The results showed that the participants preferred high sex appeal ads at the gazing stage but preferred low sex appeal ads at the evaluation stage. Further, compared to utilitarian products, hedonic products were more suited to sexually appealing ads.
Our paper contributes to the research on the controversy of sexually appealing ads. According to the behavioral results, people preferred low sex appeal ads over high sex appeal ones at the final evaluation stage, which is consistent with some previous studies (
We divided the process of experimenting with the ads into three steps: watching, thinking, and evaluating. Participants watched the ads first, then thought about the relevant factors of their preference, and finally made a preference evaluation. The N200 component, which was used to predict people’s preferences, is an event-related-potential component. N200 is a negative-going wave that peaks at the 200–350 ms post-stimulus time frame. We used the N200 component as a preference assessment for the watching stage. The subjective assessment results belonged to the evaluation stage. The LFSW component is a late component that is generated by a person’s independent thinking. Therefore, it can be considered as an indicator of mental activity in the thinking stage. In this paper, there was a difference in the LFSW between ads with different appeal intensity. We inferred that when people evaluated high sex appeal ads, conflicts arose because of their initial preferences and social expectations. However, the sexual content in the ads with low sex appeal was still within the socially acceptable range, which caused people to have different LFSWs.
Therefore, the psychological changes at the thinking stage caused the difference in preferences between the watching and evaluation stages. Further, sex appeal differences were observed in the beta band brain network. Low sex appeal ads showed stronger task-related modulations of the beta band brain networks than high sex appeal ads. This means that the beta band is related to preference evaluation and that, compared to high sex appeal ads, people may need more brain regions activated to participate in the evaluation of low sex appeal ads. This implies that people have a more in-depth understanding of low sex appeal ads. Sexually appealing ads may attract consumers at first, but excessive sexual content makes them lose interest in the ad; consumers do not make a deep evaluation of the ads. Thus, our participants had poor behavior evaluation scores and a low “small-worldness” property. In general, using sex appeal in advertising can immediately attract people’s attention; as the degree of sex appeal increases, the attraction gets stronger, as verified by the ERP results. However, consumers may have negative reactions to excessive sexual content or may wish to set an example for others and thus do not further entertain high sex appeal ads. This is also evidenced by the “small-worldness” property of the brain network. As a result, the final evaluation deviated from the initial preference. This observation has also been verified by previous studies (
Cultural differences between the East and West may be another important reason for the inconsistent preferences in the early and later stages of reaction to strongly appealing ads. Many previous studies explored the impact of the cultural differences between East and West (e.g.,
Our findings contribute to the literature on the effects of advertising for different types of products. Based on the ERP and behavioral results, low sex appeal ads were more effective in advertising hedonic products but not in advertising utilitarian ones. Consistent with emotional ads, sexually appealing ads were more suited to advertising hedonic products (
Theoretically, the current paper explored two possible factors regarding the controversy about sexually appealing ads in previous studies. Our results suggested that the effect of sexually appealing ads on consumers’ product preferences varies depending on their cognitive stage and the type of product advertised. People preferred ads with high sex appeal at the gazing stage but ads with low sex appeal at the evaluation stage. Further, compared to utilitarian products, hedonic products were more suited to sexually appealing ads.
Practically, using sex appeal in advertising is one of the commonly used strategies for marketers. Our findings suggest that for ads with high sex appeal, people may prefer them at the initial stage but not at the final stage because of social pressure. For ads with low sex appeal, their combination with hedonic products may produce positive advertising effects. During offline shopping where consumers are exposed to other individuals, high sex appeal ads may not be a smart way to advertise products as opposed to in online shopping, where the environment is relatively private. Additionally, advertising hedonic products with low sex appeal ads may be more effective than employing such ads for utilitarian products.
Social expectation bias led to the reversal of stated preferences to sexually appealing ads. In public, the participants stated that they preferred the low sex appeal ads. Future studies should employ different process measures (e.g., “think aloud” protocols or post-rating interview data) to justify this explanation. There should be a high correlation between social desirability and the stated preference for low sex appeal ads. Open-ended responses may reveal participants’ dislike for high sex appeal advertising for moral reasons. Another method would be to use procedures such as guaranteed private and anonymous data collection to minimize social expectation bias and emotional response display rules (e.g.,
We determined our sample size (
We used the N200 component as an early indicator of initial preference. Although prior studies suggest that it predicts initial subjective preferences, recent studies have shown that N200 is a weak measure of preference (
The datasets presented in this article are not readily available because the data cannot be shared for privacy restrictions. Requests to access the datasets should be directed to QW,
The studies involving human participants were reviewed and approved by Local Ethics Committee of Zhejiang University of Technology. The patients/participants provided their written informed consent to participate in this study.
FH, LZ, and QS conceived and designed the experiments. YL and QW performed the experiments. YL, QW, and WX analyzed the data. FH and QS drafted the manuscript. QS and QW revised the manuscript. QS edited the manuscript.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
We thank the reviewer who brought this limitation to our attention.