Why Women's Sexual Desire Drops Faster in Relationships

A common observation is that women's sexual desire tends to decline faster than men's within relationships. This phenomenon is puzzling, especially considering that if a woman re-mates later, her sex drive often resurges. This suggests it's not simply an age-related or fertility-related decline, but rather something tied to the dynamics of a specific relationship.

One theory posits that high sexual desire in the early stages of a relationship acts as an "adaptation to get them on the hook," a mate retention strategy. The idea is that intense sexual activity initially serves to secure commitment from a male partner. However, once that commitment is established, the perceived "need" for this strategy diminishes, leading to a decline in desire. This perspective views sex as a potential bargaining chip, particularly non-conceptive sex, which humans engage in uniquely.

The Bargaining Chip Theory

Roy Baumeister's work supports the idea that sex can function as a bargaining chip. He suggests that the initial high frequency of sex in a relationship is to "lock the male partner in" and secure commitment. Once commitment is achieved, the frequency can decrease. This aligns with studies indicating that women in relationships report having the amount of sex they desire, while men often report wanting twice as much, suggesting that couples often settle on the woman's preferred level, with men making a compromise.

Age and Fertility vs. Relationship Dynamics

While age and fertility certainly play a role in sexual desire, the rapid decline observed within the first year or two of a relationship suggests that it's not solely attributable to these factors. The decline can be surprisingly quick, with some estimates suggesting a drop by half within the first year. This points to a "within a relationship time span effect" rather than just a biological clock.

The Cost-Benefit Analysis of Sex

For men, the "cost" of sex is generally lower, and their sex drive may not decline as significantly because there isn't the same biological imperative or risk associated with it. For women, the costs of pregnancy are higher, especially as they age, until menopause. However, the rapid decline early in a relationship, even before significant age-related fertility drops, indicates a more complex interplay of factors.

Sex as a Bonding Mechanism

An alternative perspective suggests that sex bonds both partners to each other, making it a more symmetrical bonding mechanism rather than solely a female strategy to secure a male.

Understanding Human Nature and Sex Differences

The discussion then broadened to a more fundamental question: how do we understand "true" human nature and sex differences?

The "WEIRD" Societies Problem

A significant challenge in studying human psychology is the reliance on data from "WEIRD" societies (Western, Educated, Industrialized, Rich, Democratic). These societies represent a peculiar and historically recent context, potentially skewing our understanding of universal human traits.

Scarcity vs. Abundance

This leads to a debate about which environments best reveal human nature:

• Hunter-gatherer societies in environments of scarcity: This perspective argues that human nature is best understood by studying how humans lived for most of their evolutionary history, under conditions of limited resources.
• Rich societies in environments of abundance: Conversely, this view suggests that when basic needs are met, the "true" underlying traits and characteristics of human nature can finally emerge and express themselves without the constraints of scarcity.

The Abundance Paradox

This concept, similar to the "gender inequality paradox," suggests that in societies of abundance, certain traits or differences might become more pronounced. If sex differences, for example, become larger in abundant societies, it could mean that human nature is expressing itself to an "unnaturally extreme degree" because the environmental pressures that once constrained these expressions are no longer present.

Ultimately, understanding human nature and sex differences requires examining various societies, including hunter-gatherers and "WEIRD" societies. The persistence of certain traits even in environments that push against traditional sex differences can be strong evidence of an innate biological or evolutionary "nudge."