Is it true that men reach their sexual peak during late adolescence, while women come into their own at the ripe of 35? Given most couples experience mismatched desire, wouldn't this make being on the same sexual wavelength even more difficult? Also, how would one measure sexual peak anyway -- intensity of desire, sexual frequency, or overall sexual satisfaction?

Lori Brotto, a Canadian psychologist specializing in female sexuality, says sexual peak is a myth. When I interviewed her at a café on 10th Avenue near her practice, she explained:

"The myth comes from Alfred Kinsey's data. The questions he asked were for different age groups. 'What is the maximum number of orgasms you have in a given week?'"

Kinsey found that 18-year old men and 35-year old women were having the most frequent orgasms. "But what the data doesn't reflect well," Brotto says, "is why are 18-year-old men having orgasms so frequently? They're masturbating all the time." And for the women?

"Well, in 1953 when this book was published -- they were likely married, in a stable relationship and knew who they were. We know that orgasmic ability becomes more frequent with age and relationship security."

Interesting. So from one single study conducted half a century ago, a myth about the difference between male and female sexuality arose, was propagated, and became accepted as fact.

Since this time, numerous researchers have tried to figure out whether women do in fact have a later-life sexual peak. From an evolutionary perspective, a 30-something sexual summit could help maximize reproductive success. However, as we age, testosterone, which many believe is linked to libido, declines. Levels of circulating testosterone in women aged 45 are half those of women in their 20s. So is there a definitive model? 'fraid not.

In my book, Sex Drive, I asked women from America, Canada, England and Australia to reflect upon their sexual autobiographies. Discussing sexual peak, Rose, 62 said:

Believe it or not, I am experiencing a sexual peak now at the age of 62 -- but I am on hormone replacement therapy. I am very attuned to my sexuality at the moment because I have sexual opportunity. When I was married with two children there was no opportunity for strong sexual expression.

But for a significant number of older women, sex drive became less of a presence in their lives, with many "drifting off into a state of sexual indifference." For others, sexual peak depended on who they're with: "If they're with the right partner, they're always at their peak." In other words -- and I really like this idea -- female desire can be peaking all along, ebbing and flowing throughout the life course.

American psychologist David Schnarch, author of Passionate Marriage: Keeping Love and Intimacy Alive in Committed Relationships, says there are two sexual peaks. The first, genital prime, is biological, driven by our hormones and related to fertility and youth. The second, sexual prime, is social, driven by our spirits, maturity and sexual experience. Schnarch concludes that a "hormonal model is not an accurate framework for human sexual fulfillment," and that sexual prime is most often reached in one's 40s... 50s... or (bless him)... 60s. But, he argues, many don't experience this due to personal fears and insecurities.

Mmm, so although it appears that we may be more physically primed for sexual pleasures when young, there is great scope for a sexual renaissance. Sexual prime, then, is the result of "sexiness." And that, can peak at any age.

For more by Bella Ellwood-Clayton, click here.