(CNN) -- Ladies (and gentlemen): Can you find the G-spot?

Women everywhere have read or heard that they may possess a secret pleasure zone inside their bodies that, if stimulated correctly, yields intense pleasure and even orgasm.

But this so-called G-spot has never been precisely identified as a concrete biological entity. Scientists are still arguing over what it is and whether it exists at all.

Researchers at King's College London in the United Kingdom have brought the elusive G-spot to the forefront with a study of more than 1,800 female twins. The study suggests that there is no genetic basis for the G-spot and that environmental or psychological factors may contribute to whether a woman believes that she has a G-spot. The new study is published in the Journal of Sexual Medicine.

But the lead study author, clinical psychologist Andrea Burri, isn't sure that the question was asked in a way that accurately got the information the researchers were seeking, as reflected in the study's discussion section.

Her team did not physically examine the women for the presence of G-spots but instead gave participants a survey asking whether they believed that they had a "so called G-spot, a small area the size of a 20p coin on the front wall of your vagina that is sensitive to deep pressure?" (A 20p coin is about the size of an American nickel.)

They found that 56 percent of respondents answered "yes" and that there was no genetic correlation. But only about 30 percent said they were able to achieve orgasm during intercourse, which may indicate that women were confused by the G-spot question because stimulation of the G-spot is supposed to induce orgasm, she said.

The definition of G-spot in the study is too specific and doesn't take into account that some women perceive their G-spots as bigger or smaller, or higher or lower, said Debby Herbenick, research scientist at Indiana University and author of the book "Because It Feels Good."

"It's not so much that it's a thing that we can see, but it has been pretty widely accepted that many women find it pleasurable, if not orgasmic, to be stimulated on the front wall of the vagina," said Herbenick, who was not involved in the study.

The study also found correlations with personality components in women who did report having G-spots: For instance, these women tended to be more extroverted, arousable and open to experience, which may indicate a psychological component to the G-spot, Burri said.

More research is necessary to make more conclusive statements about whether the G-spot has a physiological basis, experts say.

"I don't think that these are invented experiences at all," Herbenick said. "And if at the end of the day, someone's invented something and they feel pleasure from it, then I think that's great."

The G-spot has been so difficult to identify because it is more of a physiological change -- akin to swallowing or urinating -- than an anatomic structure such as a nipple, said Dr. Irwin Goldstein, director of sexual medicine at Alvarado Hospital in San Diego, California, who oversees the peer review process for the Journal of Sexual Medicine.

But a recent study that adds credence to the G-spot concept. French researchers Odile Buisson and Pierre Foldès did ultrasounds of a small number of women having intercourse with men. By looking at the changes in the vagina, the researchers found physiological evidence of the G-spot. This study is under review at the Journal of Sexual Medicine, Goldstein said.

The G-spot is named after Dr. Ernst Grafenberg, a gynecologist known for his research on female genitalia. He described this pleasure zone of the vagina in a 1950 paper.

The 1982 book "The G Spot: And Other Discoveries About Human Sexuality" made the term "G-spot" popular.

A small study by Italian researchers in the Journal of Sexual Medicine in 2008 found that women who were able to achieve vaginal orgasms had thicker tissue between the vagina and the urethra, where the G-spot is said to reside.

A minority of women say they ejaculate when they have a G-spot orgasm. Some sex researchers say this fluid comes from a gland that's near the G-spot area.

Men also have a G-spot of sorts, below the scrotum and above the anus, Goldstein said, although it has not gotten as much attention as the more mysterious female G-spot.

Experts agree that the idea of the G-spot has put pressure on both women and their male partners to find some kind of hidden treasure that leads to orgasm from the penis alone.

"Initially, it was a good concept, because who wouldn't like the idea of 'push a button and get the best orgasm ever?' " Burri said. But those women who can't orgasm from vaginal intercourse may feel inadequate, and knowing that the G-spot may not exist can take some pressure off.

Women should explore their bodies, find out what they like, and communicate that information to their partners, Herbenick said.

"Whether you call it your G-spot or the front wall of your vagina, or if you make up a silly name for it ... at the end of the day, it's what you like and how your body works," she said.

Watch Dr. Oz discuss the G-spot and other sex secrets