According to Promiscuity author Tim Birkhead:

The rate of human sperm production is lower than that of any other mammal so far investigated. The numbers of sperm stored in the epididymis are also low. … Men, in contrast [to chimpanzees] have a more limited capacity and six ejaculations in twenty-four hours is enough to deplete the epididymal sperm stores completely. [pp. 82,84]

Research suggests that ejaculation every third day would not overtax sperm supplies. However, men have not evolved to engage in limitless ejaculation without suffering physiological repercussions. Mainstream sources that promote daily ejaculations as some sort of ‘natural’/ancestral behavior mislead the public.

All-in-all the evidence suggests that human sperm production has evolved for only a moderate rate of ejaculation.

The myth of unlimited human sperm production

It’s likely our false belief in ‘limitless’ human sperm production arose primarily because the brain’s evolved reward mechanism for pursuing sex is very strong. Male zeal for sex and the willingness to risk lives to access potential mates appear across species. After all, males more often face the potential of zero offspring. The struggle for successful fertilizations is often demanding and failure common.

The intensity of sexual pleasure makes us assume frequent ejaculation is more beneficial than it is.

  • Question: How could something that feels so great ever be a problem?
  • Answer: Our sexual expression is occurring in an environment very different from the one in which it evolved.

Many sex-positive cultures have taught moderation for millennia.  Historically, male fervor was held in check by the scarcity of sexual opportunities with novel mates. When population density arose, traditions that regulated sexual excess protected male potency.

The last half-century’s decision to dismiss the possibility of biological limits represents a sweeping departure. Across the globe and over thousands of years mankind generated a broad array of traditions and taboos to protect male potency and vitality. For example, the ancient Chinese Taoists made a science of sexual health and relationship harmony, without a hint of moralizing.

They were not alone. Almost a century ago, anthropologist A. Ernest Crawley recorded that tribal cultures all over the world believed that temporary abstinence from sex was appropriate in connection with various activities. Periodic abstinence was believed to increase male invincibility and vigor. For the same reasons, numerous cultures have also evolved ways of making love that conserve energy.