A study by researchers at the Kinsey Institute for Research in Sex, Gender, and Reproduction at Indiana University finds that men report a variety of different experiences involving sexual desire and arousal.

Men participating in focus groups expressed a range of experiences and feelings relating to such matters as the relationship between erections and desire, the importance of scent and relationships, and a woman's intelligence. The Kinsey Institute study, appearing in the April issue of the journal "Archives of Sexual Behavior," is unique because few studies so far have examined how closely the findings of decades of laboratory studies on sex actually reflect the experiences of men.

"We have a lot of assumptions about how men think and feel and behave sexually," said Erick Janssen, associate scientist at the Kinsey Institute. "We use all kinds of methods to measure men's sexual responses; in addition, we use questionnaires and surveys to ask about sexual behaviors. It's less common to sit down with men and ask them to talk about their experiences."

The focus groups involved 50 men divided into three groups based on their age (18-24 years, 25-45 years and 46 and older). Below are some examples of the different experiences reported by the men:

• Some factors, such as depression or a risk of being caught having sex, were reported by some men as inhibiting sex, while other men found that they can enhance their desire and arousal.

• An erection is not the main cue for men to know they are sexually aroused. Most of the men responded that they can experience erections without feeling aroused or interested, leading researchers to suggest that erections are not good criteria for determining sexual arousal in men.

• Many men found it difficult to distinguish between sexual desire and sexual arousal, a distinction prominent in most sexual response models used by researchers and clinicians.

• The changes in the quality of older men's erections had a direct effect on their sexual encounters, including, for some, a shifting focus to the partner and her sexual enjoyment. Older men also consistently mentioned that as they aged, they became more careful and particular in choosing sexual partners.

• The sexual history of women also mattered to the men -- but differently for different age groups. Sexually experienced women were considered more threatening by younger men, who had concerns about "measuring up," but such women were considered more arousing for older men.

Janssen and his colleagues at the Kinsey Institute have been working for more than 10 years on a theoretical model that focuses on sexual excitation and sexual inhibition. They refer to this as the dual control model of sexual response. It holds that separate and relatively independent activating and suppressing sexual systems exist within the central nervous system and that the balance between these two systems determines a person's sexual response in any particular situation. Janssen relates this to the gas and break pedals in a vehicle -- both can influence a car's behavior (you can slow down by letting go of the gas or by pressing the brake) but they do so in different ways.

This model is used around the world by sex researchers in studies on topics as varied as sexual dysfunction and sexual risk taking. To measure the propensity for sexual excitation and inhibition, the researchers designed a questionnaire.

The original questionnaire was developed for men, leading researchers at the Kinsey Institute to conduct focus groups with women in an effort to create a similar questionnaire that would be more relevant for women. Janssen said the success of women's focus groups led him and his colleagues to conduct the focus groups with men.

The findings of this latest study ultimately could lead to a more effective questionnaire for the dual control model but also can inform research efforts to better understand the variability in sexual behavior.

"One of the main conclusions of the focus group study is that, just like women, men are different," Janssen said. "Sex researchers tend to focus a lot on differences between men and women, while not giving as much attention to the differences that exist among men, and women. This research is part of a larger agenda at the Kinsey Institute of looking at individual differences. This dates back to Alfred Kinsey's original research, but in our current research we not only try to capture the variations in men and women's sexual experiences -- we also try to understand better what explains variations in those experiences."

Co-authors of the study are Kimberly R. McBride, IU School of Medicine; William Yarber, Department of Applied Health Science; Brandon J. Hill, Department of Gender Studies; and Scott M. Butler, Georgia College and State University.