We tend to think of evolution as a slow process. We often believe that humans came to be in our present form over millions of years. However, scientific discoveries have revealed that a quantum leap in consciousness happened between 100,000 and 35,000 years ago. Suddenly our brains doubled in size, giving our ancestors access to more complex cognition. We went from being the ape who stands (Homo erectus) to the ape who knows (Homo sapiens).
The Stoned Ape Theory
Many have speculated on the cause of our evolutionary leap in consciousness. Psychedelic philosopher Terence McKenna put forth an intriguing hypothesis dubbed the Stoned Ape Theory which suggests psilocybin-containing mushrooms were responsible for the dramatic increase in our cognitive ability. As our predecessors began incorporating magic mushrooms into their diet, the psychedelic experience changed their brains, effectively increasing their cognitive capacity.
With all due respect to the late and great Terence McKenna, I am intrigued by another possible explanation for our consciousness expansion. SEX. And, more specifically, female sexual pleasure.
Female Pleasure and Human Evolution
It’s generally thought that sex serves a singular evolutionary purpose: propagation of the species.
In the animal kingdom, sex is an act of reproduction. However, for our closest primate relatives, bonobos, nonreproductive copulation is common. For bonobos there is a separation of sex and reproduction. Since we share 99% of our DNA with them, it’s worth considering why they focus on sensual pleasure if it has none of the expected evolutionary gains.
Bonobos have offspring only every 5-6 years. However, even when there is no likelihood of offspring, they continually mate. And it’s not just fast and furious like other species. Bonobos take their time and really enjoy themselves. They make love gazing into each other’s eyes, copulating face to face. They hold hands and feet, French kiss, and exchange oral sex.
Bonobo females are especially into sensual pleasure. They have a high sex drive and don’t limit themselves to the opposite sex, opting more often for other females. Their same-sex erotic play is emotionally bonding. They tend to remain close to their female partners after sex.
One evolutionary purpose for bonobo's love of sex: it's less about making babies and more about social cohesion. Although their social structure is not tension-free, they tend to have more sharing behaviors and less aggression than chimpanzees. They are less likely to use fear and coercion in their social hierarchy.
Researchers have discovered that female bonobos have elevated urinary oxytocin levels after sexual encounters. Elevated levels of the molecule of love and trust make sense if the evolutionary payoff for bonobo female pleasure is empathic behavior and cooperation.
However, elevated oxytocin from female pleasure may provide another astounding evolutionary gain: the growth of the neocortex.
The Oxytocin Pathway
Oxytocin (OT) is often associated with its vital role in reproduction. However, OT has many more purposes, such as tissue remodeling. Although much of this research has focused on the role of OT and heart tissue, more recently, oxytocin has been postulated as having a direct role in the development of brain anatomy. In Oxytocin Pathways and the Evolution of Human Behavior, the author provides indirect and direct justification for the hypothesis that OT regulates the growth of the neocortex.
It's an exciting thought to ponder: Our evolutionary leap in cognitive capacity may be linked to female pleasure and oxytocin.
Darwin on Love
Could it be that instead of self-interest playing a central role in the evolution of humanity, that love was primary?
It may surprise some to learn that Charles Darwin came to this conclusion as well.
Darwin's Lost Theory of Love reveals his lesser-known work: the Descent of Man, that followed Origin of the Species. In this later volume, Darwin refers to love ninety-seven times as an essential factor in evolutionary theory. In his earlier work, Origin of the Species, Darwin only mentioned love twice.
At any rate, it’s a hopeful idea to ponder. More about female pleasure and evolutionary theory a future post.