1. Sigismund Schlomo Freud was an Austrian neurologist who founded Psychoanalysis. Freud proposed the development of sexual drives through his theory titled “Psychosexual stages of development” in childhood. During each stage, the libido is focused on different parts of the body. The concept of ‘libido’ as per Freud described any psychic, sexual energy, or instinct that resided in the ‘Id’ (pleasure principle) of a personality, acting as what drove behavior.

As an individual grows physically, particular body parts become important (called the erogenous zones), and these can be either a source of frustration or pleasure or both. There are five stages called the oral, anal, phallic, latency, and genital stages. If there is appropriate development at each stage, the child advances to the next stage and eventually grows into a healthy and successful adult. 

In his published volume “Three Essays on the Theory of Sexuality,” Freud describes a continuity between a child’s pleasure as per the psychosexual stages and the pleasure experienced by a mature adult. He quoted, “No one who has seen a baby sinking back satiated from the breast and falling asleep with flushed cheeks and a blissful smile can escape the reflection that this picture persists as a prototype of the expression of sexual satisfaction in later life” (Sigmund Freud, 1905). 

Freud emphasizes the significance of interpersonal relationships on sexual and emotional development. He draws a comparison between a mother-child relationship and the child’s later capacity for pleasure and attachment. Freud helped us understand that there is a motivational force in our desire for pleasure and the importance of balance between our intimate sexual fantasies and social norms.

As interpreted by Leon Hoffman, M.D., “Psychoanalysis encourages the idea that parents need to promote children's development so that they can eventually integrate sexuality in their lives in a balanced way, so that sexual and intimate personal bonds can be integrated as much as possible.”

2. William Howell Masters and Virginia Eshelman Johnson are widely known for their groundbreaking research work in sex psychology and the treatment of sexual issues. They developed four stages of the human sexual response that are widely recognized today. Their research dismissed various myths about sexual behavior based on sexual orientation, gender, and age. These stages are:- 

• • The excitement/arousal phase - Sexual thoughts and sexual excitement are observed with physical or psychological stimulation, but they can also occur randomly. It results in increased blood pressure, heart rate, and erected nipples. Men develop erections, and women secrete vaginal lubrication. 
  • The plateau phase - This phase is marked by full sexual arousal. Both sexes experience muscular contraction in their genitals. 
  • Orgasm - There is an extreme sense of pleasure along with rhythmic muscular contractions in the genitals.

3. The resolution phase - The sexual interest begins to decrease in this stage. Men enter a refractory period during which it was observed they are unable to orgasm again. They also observed that women might also experience a refractory period. However, due to their ability to attain multiple orgasms, they have a shortened refractory period or not at all. 

4. William Howell Masters and Virginia Eshelman Johnson stages and related findings are given in their book Human Sexual Response (1966). They also established a clinical institute called Masters & Johnson Institute, where they used a clinical therapy program developed by them to help couples experience sexual dysfunction. Their therapy and counseling techniques are highlighted in Human Sexual Inadequacy (1970).

Sexuality is one of the essential parts of lifespan, yet it has many taboos attached to it. Yet, it’s a potent force that has fought through the rigid and biased perspectives of society. It tries to bind the component that is the reason for survival and the existence of the human being itself. Sex, Sexuality, and Orientation are basic elements that define a human being that develops over the lifespan.

Sexuality can be defined as a person's identity in relation to the gender or genders to which they are typically attracted. The act of copulation or fornication has been redefined over the years to the current context of sexuality. In addition to that, what matters is two adults consent and decide to indulge in any sexual activity mutually. As two consenting adults mutually define the laws and lines they want to act upon with each other. 

India played a significant role in the history of sexual activity, from writing one of the first pieces of literature that treated sexual inetrcourse as a sexual science. It may be argued that India pioneered sex education through art and literature through the Kamasutra. The literature of various countries emphasizes human sexual activity. 

Chinese literature projects a long history of interest in affection, marital bliss, unabashed sexuality, romance, and lustful beliefs. Homosexual alliances can be seen in passages from Zhuang Zi and other works of literature such as the Tang Dynasty Yingying  Zhuang , the Qing dynasty Fu Sheng Liu, Jin Ping Mei. The world’s first novel, the Genji Monogatari (Tale of Genji), dates back to the 8th century AD. It illuminates Japan’s concept where eroticism is treated as a central part of the aesthetic life of the nobility.

The origins of human sexuality, sex, and reproduction are based on evolutionary biology and ecology. Sex, sexuality, and sexual orientation were perceived as a means for basic need and reproduction to carry forward the lineage of homosapiens when our ancestors lived as nomads, as basic survival was also difficult. 

Over time, as humans evolved into societies, or civilizations, they started making rules and moral codes of conduct to channel the basic need for sex, or procreation. This began to change the way this basic need was perceived. As a result, the concept of the institution of marriage, concubines, slaves, etc., came into existence to deal with the aspects related to sex, survival, and succession. Especially when the kings or kingdoms raged war against each other. Children and women were taken as assets to exploit in terms of sex, or childbearing, etc. 

Today the 3rd Gender has been given legal status, and the LGBTQIA community has received its long due recognition and freedom. However, it's still a long journey understanding the depth of sex and sexuality.

Ellen DeGeneres is widely known as the first openly gay woman in Hollywood. She is the highest-paid female talk-show host in the US. She had to deal with the loss of her girlfriend. Her grief led her to write a comedy monologue titled ‘Phone Call To God’, which made a shift in her career. 

Ellen discovered her talent for comedy as a teenager when her mom was going through a rough time after her parents' divorce, and Ellen made her mom laugh. She said it was a powerful thing to discover. Ellen was aware of her sexuality from a young age. She started participating in comedy shows and got cast in TV shows. She was getting success, but the spotlight brought up rumors about her sexuality. Initially, she wasn’t ready to reveal herself to her fans, but with time she changed her mind and disclosed her sexuality on the Oprah Winfrey show with 44 million viewers. She felt free and received a positive response, but then suddenly, things took a turn, and she received a lot of backlash. The ratings for Ellen's show suffered, and the show was banned. Her career was going downhill until she starred as Dory in Finding Nemo. Soon after, she came back with “The Ellen DeGeneres Show,” and it has won 38 Emmys till now. She is also now happily married to Portia De Rossi, an actress. 

Receiving public acceptance and validation about her marrying a woman was a long way to come. From receiving backlash from her fans just for her sexual orientation significantly affected her personal and professional life. She realized that her acceptance and openness about her sexual orientation opened a lot of doors for other people in the entertainment industry and also in the LGBTQA+ community. 

The story of Lili Elbe (birth name/dead name - Einar Wegener) is very widely known as she was the first person to undergo reassignment surgery. She was celebrated as the pioneering transsexual. The Oscar-winning movie “The Danish Girl” is based on the life of Lili Elbe. The story of Lili and Gerda goes hand in hand. The artist Gerda Wegener and Einar got married at the ages of 19 and 22. Gerda and Einar were artists living and working in Bohemian Paris, where Einar started to act as Lili. 

Lili stopped painting as she believed that was a part of her former life, and Gerda started her career as a model. Their personal and artistic bond was seen as unconventional at the time, so Lili was known as Gerda’s cousin to their friends. In 1930, Lili underwent reassignment surgery, but due to further surgery complications, Lili passed away. Her autobiography was published in 1933 posthumously. Her story has given many people the strength to undergo assignment surgery & inspired people with her bravery and openness.