More is not always better. This statement, according to American scientists, refers to the sperm. It is scientifically proven that large sperm are slower moving and less likely to fertilize the egg. The data were published in the journal Evolution.
For the study, researchers used special cameras spermatozoa of different species. Eventually it was found: there is a relationship between the shape and size of sperm and fertilization.
For example, in fish spermatozoa with the big head indeed more active and fast. However, in humans it is different. The speed of movement of sperm is affected by the size of the flagellum.
This study refutes the hypothesis that large sperm are functionally more active than their smaller competitors.