Rams sometimes prefer to have sex with other rams

There are more data on preference for individuals of the same sex among rams. The first description of a same-sex preference in rams was based on a total of eight subjects, four of which copulated with ewes with the intensity that rams usually show, while the other four showed little interest. All animals were then tested in an enclosure where a sexually receptive ewe and a ram were tethered to opposite sides. It turned out that the four copulating rams approached the ewes much more than the...

Variations in womens sexual behavior during the menstrual cycle

A large number of studies have addressed the issue of menstrual cycle-dependent variations in the intensity of sexual behavior in women. This is a well-liked issue that is discussed in popular magazines from one time to another, so I will not spend many lines on it. Data are conflicting and peaks of sexual intercourse frequency have been reported in the follicular phase just following menstruation (Spitz et al., 1975 Dobbins, 1980), in the periovulatory phase (Udry and Morris, 1968 Adams et...

Visual incentive stimuli

For years I have tried to find some kind of reasonably accurate data on what are or may be the sexual incentive stimuli activating approach in the human. Some sociologists and others have ventured to speculate about the factors determining the attractiveness of humans, but they have not focused on the subject at hand here. Rather they have studied the factors that may make a human attractive for marriage and that is something entirely different from the factors that determine sexual incentive...

Functions of the vomeronasal organ in relation to sexual behavior

Some believe that the vomeronasal organ is specialized for the detection of nonvolatile chemicals, that is chemicals that are not airborne but in water solution (Wysocki et al., 1980). A consequence of this belief is that the sensing subject needs to be in direct physical contact with a liquid containing the chemical and literally suck it into the nose. The vomeronasal pump will then introduce the compound into the vomeronasal organ. These events may occur when a rat is sniffing urine or feces...

Potential endocrine causes of hypoactive sexual desire disorder

It is difficult to imagine that deficiency in some gonadal hormone could account for the situational variants of hypoactive sexual desire disorder. It may also be difficult to explain the acquired variant in terms of endocrine alterations, unless we assume that the onset of these endocrine alterations coincide with the onset of hypoactive sexual desire disorder. On the contrary, an endocrine explanation may be very suitable for explaining the life-long variant. However, it is most important not...

The relationship between sexual desire motivation and excitation arousal

Desire is a term popular in the literature on human sexual behavior. Due to some undoubtedly unfounded prejudice against fashionable terms, I strongly dislike it. Its precise meaning is unclear and it is extremely difficult to use it in a comparative perspective. Proposing that a female rat desires to engage in copulatory activity is extremely repulsive. I have elsewhere argued, with convincing arguments, that the word 'desire' needs to be replaced with the word 'motivation' in any scientific...

Psychopharmacological treatments

The encouraging results reported in the clinical trials with androgens contrast sharply to the lack of progress with regard to psychopharmacological approaches. There is currently no established drug treatment for hypoactive sexual desire disorder, neither in men nor in women. Recent reviews of the treatment strategies for this disorder have focused on hormone treatments (Kohn, 2006 Nijland et al., 2006 Segraves and Woodard, 2006). No new data on the effects of drugs acting in the central...

Saint Augustine and sex the poena reciproca and the role of love

As soon as we turn from non-human to human sexual behavior, an enormously difficult complication presents itself. Unlike sexual behaviors in non-human animals, human sexual behaviors are, to a substantial degree, socially constructed. For an excellent analysis of the social construction of sexuality, the reader is referred to the brilliant classic by Gagnon and Simon (2002). Here, I will only briefly introduce the notion of human sexuality as a social rather than biological entity. Many human...

The importance of testicular hormones in men

Some effects of the removal of testicular hormones have been implicitly known for thousands of years. Starting at an unknown period of remote antiquity, castrated men, eunuchs, were used as servants in harems and as chamberlains to kings (Humana, 1973). The fact that eunuchs were preferred for employment as guards of and servants to women may suggest that already in these ancient times it was known that castrated men had reduced or no sexual interest. There are many anecdotes about preserved...

Copulatory behavior in men and women

Stages Coital

Throughout history there have been many descriptions of human copulatory behavior. Most of them belong to the fine arts, some to pornography and a few to the medical sciences. Descriptions satisfying some minimum requirements of objectivity and accuracy are more rare. Without discrediting the early pioneers in sex research, I will start my analysis of copulatory behavior with the extraordinary data collected by Alfred Kinsey and colleagues and published in two landmark books (Kinsey et al.,...

A curious observation of some consequence

Two most remarkable studies were published quite recently. They were remarkable first because they included groups of women diagnosed with hypoactive sexual desire disorder or female sexual arousal disorder according to the criteria established in DSM-IV. This is certainly admirable, but the diagnosis was not complete. There is no indication whatsoever neither with regard to life-long or acquired disorder, nor to generalized or situational disorder. These omissions are most unfortunate. The...

The high cost of the imposed association between sexual behavior and reproduction

Most of those interested in human sexual behavior realize that biological mechanisms are important. At the same time, it is accepted that the expression of sexual activities is socially rather than biologically determined. This applies to the choice of partner, to the place and time chosen for the performance of sexual behaviors, as well as for the specific behaviors displayed. Considering that procreation for a long time has been regarded as the only legitimate reason for engaging in sexual...

Sexual motivation theoretical framework

Tail Withdrawal Rat

As was pointed out in Chapter 1, sexual motivation is not activated by endogenous events but by an external stimulus. This is not the whole story, though. The external stimulus must initiate some processes within the central nervous system and these internal processes must sooner or later translate themselves into observable behavior, which means activity in skeletal muscles. This overt activity may or may not be associated with responses in the autonomous nervous system. In order to understand...