Health markers are phenotypic traits that signal some aspect of mate quality, and these indicators may be used during mate choice. Health markers are generally considered honest, condition-dependent signals.
Mate preference and mate choice in humans is notoriously complex. However, humans are the product of their evolutionary history and, in particular, two key processes: natural and sexual selection. To put this in perspective, we only need think back to our recent history over many hundreds of thousands of years. Under natural selection, traits that increased survival will have been favored. For example, individuals with a more robust immune system would likely live longer perhaps because they are more resistant to parasites and pathogens. And likewise, traits that indicate high quality, such as “good genes,” could be favored during mate choice. Under this scenario, sexual selection will favor particular individuals or genes because...