why do less clothing and more cosmetics make people see you as less human?

Researchers keep confirming that revealing more flesh and using more makeup can dehumanize you, but they haven't figured out exactly why.

Over the last decade, more and more research definitely demonstrated that poses interpreted as sexually suggestive, wearing less or more reveling clothes, and heavy use of makeup leads to more objectification. Literally. When exposed to purposefully manipulated pictures of women, study subjects tend to score them lower on traits like warmth, competence, self-agency, and experience, attributes that correspond to seeing a person as a person. And not surprisingly, the women in the images are also rated as probably having lower moral standing. We all know how often sexuality is demonized, so it would be odd if there were no negative views expressed in these studies. But there's a big question that researchers haven't yet answered.

Many of the experiments confirm that both men and women engage in dehumanizing women pictured as showing more skin or even holding alcoholic beverages, which we could chalk up to social mores elevating chastity, modesty, and abstinence and denigrating any behavior we can interpret as contrary of these values, even indirectly. But in one the latest studies, there was a tidbit that didn't get much attention. One would think that heavy makeup around the lips or heavy foundation would lead to the most dehumanized ratings, but it turns out that the most objectionable place to apply heavy makeup for 1,000 test subjects across multiple experiments was the eyes. What social construct could explain that?

Can we find out if any part of our social biases and norms surrounding nudity and cosmetics is based on a biological reaction, or are they entirely social? If biology is involved, how much? While it may seem like this shouldn't doesn't matter at first, remember that we're creatures of habit and our minds often like to work by inference, peer pressure, and experience, so being biologically predisposed to finding something in particular even slightly objectionable gives moralists, sexists, and bigots an easy in to our psyche so they can agitate against their targets and build up the societal ill will which contributes to the dehumanization of those who catch their ire.

Consider the following thought. Numerous cultures across the world have often made their poorest, lowest status members do the dirtiest jobs, often dealing with filth and waste. Pretty much no one wanted to deal with filth in their day because we naturally knew that fetid and malodorous things probably harbored disease, even when we didn't have germ theory, as we can see in the logic behind plague doctor suits of Medieval Europe. Over time, the societies which pushed the burden of dealing with waste and filth to its least powerful also had a vague understanding that they were now vectors of disease by exposure to it, and so these people became social outcasts as well, creating entire castes of "untouchables."

In other words, it's entirely plausible that our biases and judgments have some biological basis. Add in social inequalities, bad faith, and moralizing from those who benefit most from all three, and you end up with toxic and dehumanizing societal constructs. Could our ancestors have seen heavy eye makeup of ancient cultures, experienced some sort of uncanny valley effect, and we now ended up with edicts labeling anyone who goes a little heavy on mascara and eye shadow a soulless harlot? Just knowing the origins of our traditions can go a very long way towards fighting them because we're aware of not just their history, but their roots, and could think our way out of the cognitive traps our lazy minds like to set for us with just a little effort.

See: Bernard, P., Wollast, R. (2019). Why Is Sexualization Dehumanizing? The Effects of Posture Suggestiveness and Revealing Clothing on Dehumanization, SAGE Open, DOI: 10.1177/2158244019828230

Riemer, A. R., et al. (2019). She Looks like She'd Be an Animal in Bed: Dehumanization of Drinking Women in Social Contexts, Sex Roles, 80(9-10), 617-629, DOI: 10.1007/s11199-018-0958-9

Bernard, P., et al. (2020) An Initial Test of the Cosmetics Dehumanization Hypothesis: Heavy Makeup Diminishes Attributions of Humanness-Related Traits to Women, Sex Roles, DOI: 10.1007/s11199-019-01115-y