We are all familiar with the tale of human reproduction. How a courageous spermatozoon takes a harrowing journey, swimming through obstacles in the female reproductive system until finally, against all odds, it wins the race. Reaching the ovum (egg), the spermatozoon penetrates the outer layer to fertilise the egg and creates a single-celled zygote that will eventually develop into a foetus, bravely rescuing the egg from being discarded. While this biological reading evokes a knight saving a damsel in distress, a tale as old as time, the reality may be a bit more complex. Yes, even our biological understanding of reproduction is gendered.

What you may not be as familiar with is the quite active role the egg plays. Advancements in how scientists understand fertilisation made in the 20th century exhibit findings relating to the function of the egg during the process. Rather than being penetrated by a strong swimming spermatozoon, the egg plays a more active role, capturing the spermatozoon and sticking it tightly to its  zona (outer layer). Studies discovered that the swimming force of sperm cells is actually quite weak, so much so that the force of a single bond is enough to keep it connected to the outer layer of the egg. More recent research adds to insights of the active role eggs play. In 2016, researchers found that the egg will send out a wave of the hormone progesterone when it senses sperm cells are nearby, and this causes a “power kick” in spermatozoa’s tail, giving it a boost to help it reach the egg. Despite identifying an equal contribution from egg and sperm during conception, the research still portrayed the gametes with anthropomorphised, gendered roles. 

Despite all the evidence of equal role and participation of eggs and sperm cells in reproductive conception, implicit messages continue to be sent by the way we talk about the process. In reproductive biology, even seemingly impartial or objective language used in scientific papers and textbooks can subtly reinforce traditional gender roles between men and women. Descriptions of sperm cells as active, strong, penetrating, and aggressive call to mind those qualities associated with ideal masculinity in our society. The egg is described as passive and having a less important role than the sperm cell, which reinforces conceptions of women as having less to offer in society. Even the recent discovery of the “power kick” mechanism is talked about in terms of the sperm cell and the benefits it gives for the sperm cell to do its job and complete its harrowing journey, rather than focusing on the active participation of the egg. In other cases, instead of being penetrated or rescued from disuse, eggs were portrayed as capturing sperm cells, with similar negative connotations to a spider capturing a fly in its web. These descriptions, while giving the egg a more active role, cast it with an aggressive, dangerous, femme fatale characterisation. 

The scientific field sets an example for the rest of society, and so in pop culture, this gendered description of egg and sperm cells’ relationship continues to be perpetuated. This bias has seeped into society in places as simple as an inspirational quote insisting that on your worst days, you should remind yourself that you started life as the winning spermatozoon out of hundreds of millions of competitors.  Sperm cells are often portrayed as containing the entire essence of the human they will become, with little regard given to the fact that the egg also contains 23 chromosomes that will account for half a person. No regard is given to the role or even the existence of the egg. Why can we not emphasise, rather, the amazing sequence of events that occurs when an egg and a sperm cell come together and use their unique mechanisms to create life? Equally. 

It is important that we recognise the existence of gender bias in what is meant to be an objective, impartial field. Scientists have a responsibility as experts in their fields to actively seek out and question instances of bias in scientific thought.