No matter how much we have achieved in any area of our lives, true fulfillment can only be found in one thing: the emotional quality of our personal relationships.

Unfortunately, most of us have settled for something that falls below our standards and deepest desires. We all want love, passion, and intimacy yet most of us fill ourselves up with work, friends, sports, food, or causes outside the realm of passion, ecstasy, and intimate love.

The good news is that regardless of your past experience or current relationship, the promise of something deeper, richer and lasting is within your grasp.

One? Two? Twenty? How about 200? Some college students have cited as many as 237 different reasons for having sex.

From pleasure to procreation, insecurity to inquisitiveness — today’s reasons for taking a roll in the hay seem to vary as much as the terms for the deed itself. A 2010 Sexuality & Culture review of sex motivation studies states that people are offering “far more reasons for choosing to engage in sexual activity than in former times.” And we’re doing it more often, too. It is a stark contrast from historical assumptions, which tend to cite only three sexual motivators: To make babies, to feel good, or because you’re in love.

Today, sexual behaviors seem to have taken on many different psychological, social, cultural, even religious meanings. Yet, some sexologists say, at the most basic level, there is only one true reason people seek sex.

Wired for Sex

“We are programmed to do so. Asking why people have sex is akin to asking why we eat. Our brains are designed to motivate us toward that behavior,” says Richard A. Carroll, PhD, a sex therapist and associate professor in the department ofpsychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine.

The idea that humans are hard-wired for sex reflects an evolutionary perspective, says Elaine Hatfield, PhD, professor of psychology at the University of Hawaii and author of that 2010 review examining sexual motives from cross-cultural, historical, and evolutionary viewpoints.

“Evolutionary theorists point out that a desire for sexual relations is ‘wired in’ in order to promote species survival,” she tells WebMD in an email. “Cultural theorists tend to focus on the cultural and personal reasons people have (or avoid) sex. Cultures differ markedly in what are considered to be ‘appropriate’ reasons for having or avoiding sex.”

What’s Your Motive?

Why do you seek sex? Motivations generally fall into four main categories, according to psychologists at UT-Austin, who asked more than 1,500 undergraduate college students about their sexual attitudes and experiences.

• Physical reasons: Pleasure, stress relief, exercise, sexual curiosity, orattraction to a person.
• Goal-based reasons: To make a baby, improve social status (for example, to become popular), or seek revenge.
• Emotional reasons: Love, commitment, and gratitude.
• Insecurity reasons: To boost self-esteem, keep a partner from seeking sex elsewhere, or because of a feeling of duty or pressure (for example, a partner insists on having sex).

The Difference Between the Sexes

Generally speaking, men seek sex because they like how it feels. Women, although they very well may also derive pleasure from the act, are generally more interested in the relationship enhancement aspects of sex. Researchers describe these differences as body-centered versus person-centered sex.

• Body-centered sex is when you have sex because you like the way it makes your body feel. You are not really caring about the emotions of your partner.
• Person-centered sex is when you have sex to connect with the other person. You care about the emotions involved and the relationship.

By Kelli Miller Stacy
WebMD Feature