The Case of the Female Orgasm

1. Female Orgasm: A Complex Puzzle in Evolutionary Biology

Female orgasm is a source of fascination for groups ranging from sex researchers to the lay public, and evolutionists are no exception.

Multifaceted interest. The female orgasm is a topic of intense interest across diverse groups, from scientific researchers to the general public. This widespread fascination stems from its complex interplay of physiological, psychological, and social dimensions.

Evolutionary enigma. Evolutionists are particularly intrigued by the evolutionary origins and functions of female orgasm. The challenge lies in providing a historical account of how this trait emerged and persisted in the human lineage.

Bias in explanations. Many evolutionary explanations of female orgasm are flawed due to biases, including the assumption that it evolved to enhance reproductive success and the tendency to view female sexuality through a male-centric lens. A critical reevaluation of these explanations is necessary to arrive at a more accurate understanding.

2. Adaptive Explanations: The Quest for Function

The challenge in providing an evolutionary explanation is to give a historical account of how a group of organisms came to have a particular property or trait.

Adaptive accounts. Adaptive explanations assume that a trait resulted from the direct operation of natural selection. These accounts aim to describe the past history of the environment and the organism, revealing how the trait contributed to reproductive success.

Requirements for adaptations. Demonstrating that a trait is an adaptation requires evidence that:

• Variations in the trait have a genetic basis.
• The trait influences reproductive success.
• A mechanistic account explains the links between the trait and reproductive success.
• Experiments confirm the adaptive hypothesis.

Human examples. Adaptive approaches have been fruitful in examining human traits, such as the major histocompatibility (MHC) locus and the sickle cell trait. These cases provide well-confirmed examples of how natural selection has shaped human characteristics.

3. Pair-Bond Accounts: Strengthening Social Bonds

The vast bulk of copulation in our species is obviously concerned not with producing offspring, but with cementing the pair-bond by providing mutual rewards for the sexual partners.

Pair-bond theory. Many adaptive explanations of female orgasm center on the notion of a male-female pair bond, an enduring monogamous partnership. These accounts propose that female orgasm evolved to strengthen and maintain these bonds.

Reasons for pair bonding. The pair bond is thought to have been adaptive for early hominids due to:

• Increased need for protection in savanna environments.
• Economic dependence of females on males with hunting skills.
• Extended period of infant dependency.

Problems with pair-bond accounts. These accounts often mischaracterize female sexuality, assuming that female orgasm reliably occurs with intercourse and that female sexual response is similar to male sexual response. They also neglect the orgasm/intercourse discrepancy.

4. Beyond Pair Bonds: Alternative Adaptive Theories

It is not necessary that women enjoy intercourse in order to become pregnant; but if pregnancy is to occur often enough to ensure continuity of the species, it is important that copulation be rewarding for both sexes.

Non-pair-bond explanations. Some adaptive explanations of female orgasm do not rely on the pair-bond concept. These accounts propose that female orgasm evolved to serve other functions, such as stimulating male orgasm or inducing abortion in unfavorable circumstances.

Female-centered explanations. Other theories focus on the reproductive advantage to the female alone, rather than to the male-female combination. These accounts suggest that female orgasm may have evolved to relieve pelvic congestion or to enable females to choose mates based on their orgasmic performance.

Problems with alternative theories. These explanations often suffer from logical flaws, unsupported assumptions, and a failure to address the orgasm/intercourse discrepancy. They also tend to assume that female orgasm is tied to reproductive success without sufficient evidence.

5. The Byproduct Account: A Non-Adaptive Explanation

Human female orgasm is best regarded as a potential.

Symons's hypothesis. Donald Symons proposed that female orgasm is not an adaptation, but rather a byproduct of embryological development. According to this view, the capacity for orgasm is present in all mammals, but is activated in females of only a few species.

Embryological origins. The penis and clitoris are homologous organs, arising from the same embryological tissue. The nervous and erectile tissues involved in orgasm in both sexes also have a common origin.

Male nipple analogy. Just as male nipples are a byproduct of selection on female nipples, female orgasm is a byproduct of selection on male orgasm and ejaculation. This account explains the orgasm/intercourse discrepancy and the prevalence of masturbation among women.

6. The Upsuck Hypothesis: Sperm Competition and Orgasm

It is now accepted that the sickle cell trait confers some protection against malaria during a critical period of early childhood.

Sperm competition. Sperm competition refers to the competition between sperm from different males to fertilize the eggs of a single female. Some theories propose that female orgasm evolved to influence the outcome of sperm competition.

Uterine upsuck. These theories rely on the "upsuck hypothesis," which claims that female orgasm creates suction in the uterus, drawing sperm into the reproductive tract. This is thought to give females control over which male's sperm fertilizes her egg.

Problems with the upsuck hypothesis. The evidence for uterine upsuck is weak and contested. Moreover, even if upsuck does occur, it is unclear whether it significantly affects fertility or reproductive success.

7. Statistical and Methodological Flaws: A Critical Examination

The hypothesis is made still more plausible by many examples establishing strong links between the nose, physiology, and emotions.

Methodological problems. Many studies of female orgasm suffer from methodological flaws, including small sample sizes, non-representative samples, and reliance on self-reporting. These issues raise doubts about the accuracy and generalizability of the findings.

Statistical shortcomings. Some studies employ inappropriate statistical methods, such as using parametric tests on non-normal data. These errors undermine the validity of the conclusions drawn from the data.

Replication failures. Some findings, such as the correlation between male symmetry and female orgasm, have failed to be replicated in independent experiments. This further weakens the support for these hypotheses.

8. Bias

The sutures in the skulls of young mammals have been advanced as a beautiful adaptation for aiding parturition, and no doubt they facilitate, or may be indispensable for this act; but as sutures occur in the skulls of young birds and reptiles, which have only to escape from a broken egg, we may infer that this structure has arisen from the laws of growth, and has been taken advantage of in the parturition of the higher animals.

The role of assumptions. Evolutionary models rely on assumptions about ancestral traits, mating systems, and the nature of female sexuality. When these assumptions are contradicted by available evidence, the explanations are undermined.

Types of bias. At least two main biases have negatively affected the evolutionary explanations of female orgasm:

• Adaptationism: Assuming that the trait was naturally selected because it has a specific function.
• Androcentrism: Assuming that female sexual response is like male sexual response to the same stimuli.

Impact of biases. These biases have led to flawed reasoning, selective use of evidence, and misinterpretations of female sexuality.

9. Androcentrism and Procreative Focus: Skewing the Lens

There have been various trends over the years away from or toward the view that men and women have similar sexual responses, but, I shall argue, the overwhelming evidence is that women respond differently to the act of intercourse than men do.

Male-centered perspective. Androcentrism involves viewing female sexuality through a male-centric lens, assuming that male experiences and desires are the norm. This bias can lead to a neglect of the unique aspects of female sexual response.

Procreative focus. Procreative focus assumes that all evolutionarily significant sex is reproductive sex, leading to an overemphasis on intercourse and a neglect of other forms of sexual activity. This bias can distort the understanding of female sexuality and its potential functions.

Consequences of bias. Androcentrism and procreative focus can result in:

• Mischaracterizations of female sexual response.
• Neglect of the orgasm/intercourse discrepancy.
• Failure to consider alternative explanations for female orgasm.

10. Community Objectivity: Striving for Balanced Perspectives

The analysis there shows that there is a way out of the problems which anyone seeking an explanation of female orgasm encounters.

Longino's framework. Helen Longino's framework for community objectivity emphasizes the importance of:

• Publicly recognized forums for criticism.
• Responsiveness to critical discourse.
• Publicly recognized standards of evaluation.
• Tempered equality of intellectual authority.

Failures in the female orgasm debate. The evolutionary community has struggled to meet Longino's criteria, particularly with regard to:

• Shared standards of evaluation.
• Representation of dissenting perspectives.

Moving forward. To improve the objectivity of inquiry into female orgasm, it is essential to:

• Critically examine background assumptions.
• Consider alternative explanations.
• Promote open and inclusive dialogue.

Last updated: February 24, 2025