According to recent studies, the best sperm doesn’t necessarily come from the bigger packages – nor the most attractive. Not only that, but the effectiveness of it also depends on a lot of things that were not yet thought to be connected to them.
In the Animal World, Less is Also More
Sperm accommodates to the size of the female body, since it has to be able to swim far and fast enough to reach the eggs, so bigger female bodies mean smaller sperm for their male counterparts. Recent research suggests that among mammals, smaller species have larger sperm and larger ones tend to invest in smaller units of the stuff.
Apparently, Manly Men Don’t Have Manly Sperm
According to studies, males with bigger bodies and horns or deeper voices have been observed as producing less sperm than others. In humans specifically, apparently, men with more attractive voices have lower quality sperm.
The definition of ‘attractive’ is pretty subjective, but we’ll take their word for it. Males also have the ability to control the sperm they produce through varying factors, including the quality of the female and the risk of ‘sperm competition’. For example, men looking at explicit images of two girls and one guy have been shown to produce more sperm than those looking at images of three girls. Go figure!
There is Such a Thing As Cryptic Female Choice
The study also validates the existence of Cryptic Female Choice, which happens when females use physical or chemical means to control the male’s chances to fertilize her eggs. In certain species, females will mate with several males but selectively fertilize eggs only with the largest sperm or the ones with the more compatible immune system genes.
