I’m not the first one to wonder why in humans, it’s often the females who adorn themselves. It’s not natural and you need to look no further than newly discovered Eresus hermani

to see yet another example of this.  Which one do you think is the female?

You guessed it. The one on the left. According to biologist Paulina Mena “Evolutionarily speaking, sexual selection has to do with investment in reproduction. The mode in nature is that females invest more in making gametes and in many cases in parental care than males. This means that females maximize their reproductive success by being choosy. This is what leads to the elaborate adornments, bird songs, dances, etc. in males. They are trying to be picked.”

Of course,as my anthropologist/sociologist friends point out, not all human cultures put an emphasis on female adornment. In some cultures, males and females are equally adorned or not and in others, the men are the fancy ones.  Jeff Bass points out that “There is a general observation that there tends to be less gender equality (or more female dis-empowerment) in societies based on intensive agriculture.” This possibly comes as women are less central to economic production, and is less of a factor in industrialized countries where there’s plenty of work for women to do. In this case, adornment is less important.

When males and females look different, it’s called sexual dimorphism. (Sexual dichromatism is the term for different coloration between males and females.) As far as humans go, we don’t have exaggerated sexual dimorphism. Some studies have suggested that when males and females look similar to each other, there is less fighting and competition among males. Is grooming oneself, trying to look different, encouraging competition? If we were a gender neutral society, would we be more peaceful? (more on this topic in the next post)