Does Briffault’s Law Apply to Human Relationships?

Michelle Overman, Author
Updated on May 1, 2024

Briffault’s law states: “The female, not the male, determines all the conditions of the animal family. Where the female can derive no benefit from association with the male, no such association takes place”. This idea asserts that females determine whether or not a relationship takes place. Essentially, they seek to understand if the benefits outweigh the costs. If the benefits exceed the costs, females agree to enter into a relationship.

peacock showing it's feathers

In the animal world, Briffault’s law is noticeably on display. Some male birds display their feathers or build nests to illustrate their worth as potential mates. Other animals, like kangaroos, actually fight to illustrate their dominance and strength. It is then up to the females to take note of these exhibitions and decide if they want to engage with the males. To understand the concept and how it could potentially apply to humans, Briffault’s law includes several other aspects.

Although a female might benefit from a relationship at the start, she may not necessarily continue to engage in the relationship over time. In other words, she requires the benefits to last in order to stay in the relationship. For example, a woman begins dating a man who fulfills her need for emotional intimacy. However, over time, the man becomes consumed with work and the couple spends less time together. The emotional intimacy then begins to fade. Even though the benefits she enjoyed from the relationship were once strong, the woman may decide to end things because her needs are no longer being fulfilled.

A woman may promise to engage in a relationship with a man based on a benefit she believes she will receive. Once that benefit is provided, her promise is nullified, and she no longer has to remain in the relationship. For example, a woman might promise to sleep with a man once she feels he has shown that he loves her. Even if the man reveals his love through certain desirable behaviors, a woman may decide to not follow through with her initial promise.

A man’s promise to deliver on a potential future benefit does not necessarily secure a woman for long. The wait for said benefit to materialize must be short and is all dependent on how much the woman trusts the man. For example, a man asks a woman for a loan, promising that he will double what she’s given him and in turn, he will be able to care for her. For the woman to stay in the relationship, she has to trust the man, and he must not keep her waiting for long.

Briffault’s law does make some sense in evolutionary terms. However, it can sound a bit superficial. On a relational level, Briffault’s law brings up the idea of weighing costs versus benefits. Especially in the dating phase, that idea is clearly relevant. Individuals learn about each other and decide whether or not they want to enter into a relationship based on what they perceive to be the benefits.

Briffault’s law also reveals another idea that can ring true; even after entering into a relationship, the continuation of the relationship is not a guarantee. The benefits must still outweigh the costs throughout the relationship. Essentially, if needs are not getting met, the relationship often falls apart.

Part of any relationship is experiencing levels of intimacy that meet each person’s needs. Briffault’s law specifically speaks of women having control over whether or not a relationship takes place. For some individuals, this might be the case. However, it seems the basic idea can apply to any relationship and include any gender. All in all, it is important to take inventory of your relationship and ensure that the benefits outweigh the costs.


  • Briffault, R. (1931). The Mothers Vol. I (p. 191). New York, NY: The Macmillan Company.
Michelle Overman, Author

Michelle is a Licensed Marriage & Family Therapist working as a counselor for students, faculty, and staff at Abilene Christian University in Texas. She works with athletes, bridging the gap between athletics and mental health at ACU. Michelle ran her own private practice in Austin, Texas where she worked with a diverse population, including couples and families.