The Science of Why We Have Orgasms

But they are not universal to all human beings. According to a 1999 study, about 43% of women and 31% of men in the U.S. between ages 18 and 60 meet criteria for sexual dysfunctions.

So, that being said, what can science tell us about them? 

As it turns out, science doesn't really know that much about them. But, scientists have managed to uncover some interesting information nonetheless.

To date, we know, or think we know, the following about orgasms:

- Orgasms can be involuntary and do not always need to involve sexual desire (during rape or even, in some cases, exercise);

- Orgasms can occur without any genital excitation;

- Orgasm disorders are not limited to one sex (as we've seen);

- Orgasms appear to have multiple potential health benefits due to the hormones and other chemicals that are released by the body during an orgasm;

- 1 in 3 men appear to suffer from or have experienced at some point, premature ejaculation;

- Orgasms appear to have once been a requirement for ovulation (more on this later);

- Orgasms appear to boost fertility;

- Female orgasms might have evolved from male ones, and;

- Female orgasms have long been linked to psychological, as well as physical, arousal, but it might also be true for men.

All well and good, but before we go further, it might be useful to actually define what an orgasm is.

What is an orgasm?

According to the Oxford English Dictionary, an orgasm is defined as:

"The moment during sexual activity when feelings of sexual pleasure are at their strongest."

Straight forward enough, but orgasms are defined a little more graphically by medical professionals and psychologists:

"The highest point of sexual excitement, characterized by strong feelings of pleasure and marked normally by ejaculation of semen by the male and by involuntary vaginal contractions in the female." - Medical Dictionary.

But, there are also several types of orgasms too. Just to overcomplicate something that should be very simple to define.

Orgasms are also subcategorized, by some researchers, into the following:

- Combination or blended orgasms: a variety of different orgasmic experiences blended together, obviously. 

- Multiple orgasms: a series of orgasms over a short period of time.

- Pressure orgasms: orgasms that arise from the indirect stimulation of applied pressure. This is quite common in children.

- Relaxation orgasms: orgasm deriving from deep relaxation during sexual stimulation.

- Tension orgasms: a common form of orgasm, from direct stimulation often when the body and muscles are tense.

So there you go. That's probably more than you ever want to know about orgasms.

What are the causes of orgasms?

The obvious answer is the height of sexual or erotic stimulation, usually during sexual intercourse, but that's not the whole story. What is clear, however, is that they most often occur following a period of continuous stimulation of erogenous zones like the genitals (obviously), anus, nipples, and perineum.

When this occurs, orgasms are the end result of two basic physical responses.

The first is called vasocongestion. This is the process where body tissues tend to fill up or swell, with blood (think of an erection for example).

That is followed by another process called myotonia. This is where muscles tense in both a voluntary and involuntary manner. 

There have been some interesting reports of people experiencing orgasms when you might expect them not to. For example, at the onset of epileptic medicine or foot amputees feeling orgasms in their phantom limb.

Paralyzed patients from the waist down can also experience orgasms. This suggests that it is the central nervous system, not necessarily orogenous zones, that are key to experiencing orgasms. 

Some research into this area, in particular, has revealed some very interesting information.

Between 2001 and 2006, Dr. Marca Sipski-Alexander conducted studies that showed that about 50% of 45 men and 44% of 68 women of paralyzed people were able to have orgasms under controlled conditions. This was achieved with the help of adult videos and genital stimulation by hand or vibrator.

This would suggest that orgasms might be, in part, reflexive, like urinating. If true, this would appear to suggest that orgasms are the result of localized nervous connectivity in the lower body, rather than the nervous system as a whole.

In other words, receiving sexual stimulation signals from the genitals do not need to reach the brain to climax. This suggests that the old joke that men have another brain in their pants might have some merit. 

But, of course, a lot more work needs to be conducted before we can prove this conclusively. 

Where does the female orgasm come from?

Whilst male orgasms seem to be a much simpler cause and effect process, female orgasms have long been more elusive. This has prompted many to wonder why females are able to orgasms at all.

But, it turns out, orgasms might have a very primeval origin. So much so, that we may be able to trace its origin to our deep mammalian past.

In many lower mammals, the act of sex is required for females to ovulate. It appears that at some point during our evolution, ovulation became automatic and was divorced, in a sense, from the act of sex.

A study in the Journal of Experimental Zoology tried to track down when this might have occurred. The study compared primitive mammals with higher, more complex ones, to see how female orgasms changed over time.

It turns out that solitary animals, like cats, tend to experience male-induced ovulation in order to breed. They also found that these mammals showed signs of a physiological reaction that is comparable, or similar, to human orgasms - mainly the body was flooded with prolactin. 

This is the same hormone released by human females during climax. 

Placental mammals, like us and primates, tend to ovulate spontaneously (menstruation). This is thought to be a consequence of our becoming social animals rather than solitary. 

If true, it would suggest that orgasms are an ancestral 'vestigial' mechanism from our deep past. Researchers also found that as ovulation stopped depending on orgasm, the clitoris also stopped being located inside the vaginal canal.

The study also concludes that whilst the female orgasm has lost its ancestral function, it can still speed up ovulation in humans. But this is only if ovulation was going to occur within the hour.

But, that being said, orgasms in males and females have since changed their role for our species beyond pure reproduction. They are, and will always be, a key part of having sex.

It makes you enjoy the experience and, most importantly, brings you and your partner closer together as a couple.