Human sexual activity, human sexual practice or human sexual behaviour is the manner in which humans experience and express their sexuality. People engage in a variety of sexual acts, ranging from activities done alone to acts with another person in varying patterns of frequency, for a wide variety of reasons. Sexual activity usually results in sexual arousal and physiological changes in the aroused person, some of which are pronounced while others are more subtle. Sexual activity may also include conduct and activities which are intended to arouse the sexual interest of another or enhance the sex life of another, such as strategies to find or attract partners, or personal interactions between individuals. Sexual activity may follow sexual arousal.
A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavior of the receiving individuals. There are alarm pheromones, food trail pheromones, sex pheromones, and many others that affect behavior or physiology. Pheromones are used by many organisms, from basic unicellular prokaryotes to complex multicellular eukaryotes. Their use among insects has been particularly well documented. In addition, some vertebrates, plants and ciliates communicate by using pheromones. The ecological functions and evolution of pheromones are a major topic of research in the field of chemical ecology.
Sexual themes are frequently used in science fiction or related genres. Such elements may include depictions of realistic sexual interactions in a science fictional setting, a protagonist with an alternative sexuality, a sexual encounter between a human and a fictional extraterrestrial, or exploration of the varieties of sexual experience that deviate from the conventional.
Sexual attraction is attraction on the basis of sexual desire or the quality of arousing such interest. Sexual attractiveness or sex appeal is an individual's ability to attract other people sexually, and is a factor in sexual selection or mate choice. The attraction can be to the physical or other qualities or traits of a person, or to such qualities in the context where they appear. The attraction may be to a person's aesthetics, movements, voice, among other things. The attraction may be enhanced by a person's body odor, sex pheromones, adornments, clothing, perfume or hair style. It can be influenced by individual genetic, psychological, or cultural factors, or to other, more amorphous qualities. Sexual attraction is also a response to another person that depends on a combination of the person possessing the traits and on the criteria of the person who is attracted.
Sexual stimulation is anything that leads to sexual arousal or orgasm. This thing can be physical or of other senses, and is known as a stimulus.
Heteroflexibility is a form of a sexual orientation or situational sexual behavior characterized by minimal homosexual activity in an otherwise primarily heterosexual orientation, which may or may not distinguish it from bisexuality. It has been characterized as "mostly straight". Although sometimes equated with bi-curiosity to describe a broad continuum of sexual orientation between heterosexuality and bisexuality, other authors distinguish heteroflexibility as lacking the "wish to experiment with ... sexuality" implied by the bi-curious label. The corresponding situation in which homosexual activity predominates has also been described, termed homoflexibility.
Concealed ovulation or hidden estrus is the lack of any perceptible change when an adult female is fertile and near ovulation. Some examples of perceptible changes are swelling and redness of the vulva in baboons and bonobos, and pheromone release in the feline family. In contrast, the females of humans and a few other species that undergo hidden estrus have few external signs of fecundity, making it difficult for a mate to consciously deduce, by means of external signs only, whether or not a female is near ovulation.
Human male sexuality encompasses a wide variety of feelings and behaviors. Men's feelings of attraction may be caused by various physical and social traits of their potential partner. Men's sexual behavior can be affected by many factors, including evolved predispositions, individual personality, upbringing, and culture. While most men are heterosexual, there are minorities of homosexual men and varying degrees of bisexual men.
Why Is Sex Fun? The Evolution of Human Sexuality is a 1997 book about the evolution of human sexuality by the biologist Jared Diamond.
Human sexuality is the way people experience and express themselves sexually. This involves biological, psychological, physical, erotic, emotional, social, or spiritual feelings and behaviors. Because it is a broad term, which has varied with historical contexts over time, it lacks a precise definition. The biological and physical aspects of sexuality largely concern the human reproductive functions, including the human sexual response cycle.
A Natural History of Rape: Biological Bases of Sexual Coercion is a 2000 book by biologist Randy Thornhill and anthropologist Craig T. Palmer, in which the authors argue that evolutionary psychology can account for rape among human beings, maintain that rape is either a behavioral adaptation or a byproduct of adaptive traits such as sexual desire and aggressiveness, and make proposals for preventing rape. They also criticize the assumption that there is a connection between what is naturally selected and what is morally right or wrong, which they refer to as the "naturalistic fallacy", and the idea, popularized by the feminist author Susan Brownmiller in Against Our Will (1975), that rape is an expression of male domination and is not sexually motivated.
Survival of the Sickest: The Surprising Connections Between Disease and Longevity is a 2007 New York Times Bestselling science book by Sharon Moalem, an evolutionary biologist and neurogeneticist, and Jonathan Prince, senior advisor and speechwriter for the Clinton administration. It was originally titled, Survival of the Sickest: A Medical Maverick Discovers Why We Need Disease.
Sex at Dawn: The Prehistoric Origins of Modern Sexuality is a 2010 book about the evolution of human mating systems by Christopher Ryan and Cacilda Jethá. In opposition to what the authors see as the "standard narrative" of human sexual evolution, they contend that having multiple sexual partners was common and accepted in the environment of evolutionary adaptedness. The authors contend that mobile, self-contained groups of hunter-gatherers were the norm for humans before agriculture led to high population density. Before agriculture, according to the authors, sex was relatively promiscuous and paternity was not a concern. This dynamic is similar to the mating system of bonobos. According to the book, sexual interactions strengthened the bond of trust in the groups. Far from causing jealousy, social equilibrium and reciprocal obligation were strengthened by playful sexual interactions.
Odour is sensory stimulation of the olfactory membrane of the nose by a group of molecules. Certain body odours are connected to human sexual attraction. Humans can make use of body odour subconsciously to identify whether a potential mate will pass on favourable traits to their offspring. Body odour may provide significant cues about the genetic quality, health and reproductive success of a potential mate.
The Evolution of Human Sexuality is a 1979 book about human sexuality by the anthropologist Donald Symons, in which the author discusses topics such as human sexual anatomy, ovulation, orgasm, homosexuality, sexual promiscuity, and rape, attempting to show how evolutionary concepts can be applied to humans. Symons argues that the female orgasm is not an adaptive trait and that women have the capacity for it only because orgasm is adaptive for men, and that differences between the sexual behavior of male and female homosexuals help to show underlying differences between male and female sexuality. In his view, homosexual men tend to be sexually promiscuous because of the tendency of men in general to desire sex with a large number of partners, a tendency that in heterosexual men is usually restrained by women's typical lack of interest in promiscuous sex. Symons also argues that rape can be explained in evolutionary terms and feminist claims that it is not sexually motivated are incorrect.
Demisexuality is a sexual orientation in which an individual does not experience primary sexual attraction – the type of attraction that is based on immediately observable characteristics such as appearance or smell, and is experienced immediately after a first encounter. A demisexual person can only experience secondary sexual attraction – the type of attraction that occurs after the development of an emotional bond. The amount of time that a demisexual individual needs to know another person before developing sexual attraction towards them varies from person to person. Demisexuality is generally categorized on the asexuality spectrum.
Sharon Moalem is a Canadian–American physician, scientist, and author. Dr. Moalem is an expert in the fields of rare diseases, sex differentiation, neurogenetics, biotechnology and has been described as a polymath. He is the author of the New York Times bestselling book Survival of the Sickest, as well as How Sex Works, Inheritance and The Better Half. His clinical genetics research led to the discovery of three rare genetic syndromes, hypotrichosis-lymphedema-telangiectasia-renal defect syndrome, a form of SRY-negative XX male sex reversal as well as a nephronopthisis associated ciliopathy. His research led to the discovery of a new class of antibiotics that specifically target superbug microorganisms such as Methicillin-resistant Staphylococcus aureus (MRSA). Moalem was the first to propose that the progressive neurodegeneration associated with dementia and Alzheimer's disease might be caused or exacerbated by an excessive amount of the metal iron in the brain. Moalem has cofounded two biotechnology companies and has been awarded 25 patents for his inventions in biotechnology and human health.
No study has led to the isolation of true human sex pheromones, although various researchers have investigated the possibility of their existence.
The ovulatory shift hypothesis holds that women experience evolutionarily adaptive changes in subconscious thoughts and behaviors related to mating during different parts of the ovulatory cycle. It suggests that what women want, in terms of men, changes throughout the menstrual cycle. Two meta-analyses published in 2014 reached opposing conclusions on whether the existing evidence was robust enough to support the prediction that women's mate preferences change across the cycle. A newer 2018 review does not show women changing the type of men they desire at different times in their fertility cycle.
Olfactic communication is a channel of nonverbal communication referring to the various ways people and animals communicate and engage in social interaction through their sense of smell. Our human olfactory sense is one of the most phylogenetically primitive and emotionally intimate of the five senses; the sensation of smell is thought to be the most matured and developed human sense.
