When sex doesn't sell

The idea of using "sex" or "sex appeal" to help sell a product is not new. It's been used to sell alcohol, cars, jeans, perfume, sports shoes, the list is almost endless (the fact that it is almost exclusively a heterosexual males definition of "sex appeal", especially with cars and alcohol, is perhaps rather damning of our society but not something I am going to discuss). And you can see why, it genuinely does increase sales of these products (see here for evidence). But another famous (and arguably more controversial) example is when almost naked women are used to promote ethical causes e.g. PETA's many adverts. 

The logic makes sense: putting semi-naked women in adverts with products increases sales and makes the brand more recognisable and memorable, so these results should apply to other products and causes e.g. stop wearing fur. 

But does using sex appeal really result in greater support for these causes? That's what Bongiorno et al. (2013) wanted to find out. In their study they showed male participants PETA ad campaigns that either featured women fully clothed or scantily clothed. The ads were promoting the same campaign, controlling for possible effects of different campaigns being more popular. They were then asked to rate how aroused they were, the uniquely human characteristics of the women in the ad (lower ratings on the scale indicated dehumanisation) and their behavioural intentions to support PETA in the future. 

They found that support for PETA was reduced in the "sexualised women" condition and this effect was explained by the dehumanising effect of having the women scantily clad rather than because the men were more aroused (reduced support for PETA was mediated by negative uniquely human ratings). 

This is a very interesting result but there are some problems with it. The participant's arousal levels were self-reported so the reliability of those results can be called into question (you can't be sure that the participants would give exactly the same results if they were presented the materials again), as well as the validity (is it actually measuring arousal?). A physiological measure of arousal would have been more accurate (though the experiment would have to change from an online questionnaire to a lab experiment, which is more expensive and harder to organise). The participant's support for PETA was also measured via self-report so a more objective measure (e.g. how much they would donate to a PETA cause) would be more reliable. It was also asking about their behavioural INTENTION to donate, rather than how much they think they would donate or indeed how much they actually would actually donate, so the validity of their results (how much we can be sure that they are measuring changes in support levels) is not 100%.

They performed a follow-up study with a much larger sample and mixed gender. They also asked the participants to think of ways to help PETA in the future. They found the same result (reduced behavioural intention to support PETA mediated via dehumanisation of women) and fewer suggestions were offered in the "sexualised women" condition. 

Whilst the study isn't perfect, I do think it is a good indicator that using sexual imagery (specifically almost naked women) to gain support from men for an ethical campaign actually results in less support for that group. So if you want to advertise for an ethical campaign, do it ethically (otherwise you will deter supports of both genders).

References:
Bongiorno, R.; Bain, P.; & Haslam, N. (2013). When Sex Doesn't Sell: Using Sexualised Images of Women Reduces Support for Ethical Campaigns. PLoS ONE, 8 (12).
Reichert, T. (2002). Sex in Advertising Research: A Review of Content, Effects, and Functions of Sexual Information in Consumer Advertising. Annual Review of Sex Research, 13, 1, 241