Communication systems designed to accurately convey information can all be exploited for selfish purposes. Famous examples are rampant in the natural world. Several species of butterflies fool predators into thinking that they are raptors with their wing markings mimicking raptor-like eyes; several non-toxic animals take on the coloration of toxic species; angler fish dangle a biologically sophisticated lure for passersby - as they remain hidden and ready to strike - and this is just the tip of the iceberg (see Dawkins, 1989). The biological world is full of deceptive signals.
Given the centrality of mating to Darwin's bottom line (reproductive success), it makes sense that mating-relevant deception would typify the behavioral arsenal across the spectrum of sexually reproducing animals. And it does. Satellite male sunfish fool larger, dominant males into thinking that they are females - thus allowing the satellites to not get chased away - giving them prime real estate when a females comes to a nest of a dominant male to release her eggs. Satellite males, who come in to blast the eggs with their sperm, have the timing of this deception down to a science. Male preying mantises offer mates nuptial gifts - usually small clumps of dead insects (see Dugatkin, 2003), that offer a nice, nutritional snack for the female. But when food is rare, they'll offer deception gifts, clumps of mud that look similar to the insect clumps - sort of like a cubic zirconium instead of a diamond. Sometimes this deceptive strategy works better than others.
When applied to the domain of mating, research on deception raises several questions. Are people better at lying in mating-relevant scenarios and, related, are people better at detecting lies in the mating domain (compared with in other life domains)? Given how high the costs can be of getting this wrong, from an evolutionary standpoint, we predict that there have been particular selective pressures for people to be especially effective at lying when it comes to mating-relevant situations and we expect this ability to go hand in hand with a similar increase in deception-detection ability in the world of mating. This all should be part of human mating intelligence.
Glenn Geher is the coauthor of the new book Mating Intelligence Unleashed: The Role of the Mind in Sex, Dating, and Love.