He is the author of several books, he gives public speeches and teaches on issues of gender-based violence, the lives of men and boys, and gender and sports.
He was the president of the Pacific Sociological Association in 2010-2011, and in 2011 the California Women's Law Center presented him with the Pursuit of Justice Award.
He obtained a Ph.D. in sociology in 1985 from the University of California, Berkeley with a dissertation titled Masculinity and Sports: An Exploration of the Changing Meaning of Male Identity in the Lifecourse of the Athlete.
In an article about a "fight club" in Menlo Park, California, Messner remarked that men involved in them "often carry bottled-up violent impulses learned in childhood from video games, cartoons and movies.
He discusses these ideas through various articles and explores different topics such as the participation of women in sports as well as what it means to be 100% straight.
In this article, he discusses how he as a teenager was influenced to become a jock because of his height and build and, as a result, repressed his sexual fluidity in fear of being outcast.
It is fueled by "soft-essentialism", Messner's theory of the shared belief that boys and girls are inherently different as opposed to "hard essentialism," which basically creates a more categorical structure for men.
Women, however, are routed towards sports like softball or even in different leagues altogether giving them choices and complicating the meaning of equality.
Male entitlement to women's bodies has become a standard in societies such as these and reflects the values that feminists like Messner aim to change.
Women are expected to remain virgins until marriage and chastity thereafter even though their sexuality is a family matter, usually determined by the patriarch on when and who she weds.
Messner examines gender and sexuality and concludes that they play an important role in determining one's place in society.
They can shape the way people behave and develop and can mold views and actions to fit society's standards.
It is fueled by notion that men and women are inherently different, a term Messner coins as soft essentialism.
For example, countries such as Germany, Denmark, and Norway have the closest gender gap in the workplace and they have some of the most powerful economies because of it according to Reding who states, "Humans are distinguished in their contributions to society by character, ability, and motivation, and there is no meaningful correlation between those traits and sex and sexuality".
[8] Overall, Messner believes that only through integration and mutual respect in all institutions (particularly sport) can we begin to grow relationships between men and women that allow for a better future for both parties.
He states in his online biography: "My teaching and research were sparked and continue to be animated by the movements for social justice that erupted in the 1960s, 1970s and beyond, especially feminism".
In his paper, "Gender ideologies, youth sports, and the production of soft essentialism" Messner introduces the concept of soft essentialism as "a currently ascendant hegemonic ideology… that valorizes the liberal feminist ideal of individual choice for girls, while retaining a largely naturalized view of boys and men".
However, by offering girls equal opportunity, soft essentialism does not "endorse categorical social containment of women in domestic life".
Through extensive research and interviewing of youth soccer, baseball, and softball coaches about boys, girls, and gender, Messner found that most adults had a tendency to describe girls' lives as being full of choices – a way of thinking that Messner argues is a major accomplishment of liberal feminism.
In his conclusion, Messner determines that there exist three main sources of strain that proliferate hegemonic gender inequality in the form of soft essentialism: working class mothers, today's largely unreconstructed and categorical view of boys, and the celebration of equal opportunity and free choice for girls.
On his website he breaks his research down into three main areas: "First, [he] has conducted a longitudinal content and textual analysis of gender in televised news and highlights programs.
In his most recent article on sports media, "Women Play Sport, But Not on TV: A Longitudinal Study of Televised News Media" he and co-authors Cheryl Cooky and Robin Hextrum analyze 6 weeks of local and national news coverage.
His most recent contribution to feminism is his co-authored book, Some Men: Feminist Allies and the Movement to End Violence Against Women, which was released in March 2015 through the Oxford University Press.
As a general trend, Messner believes that it is in the best interest of men to support the feminist movement and the end of sexism.
He writes, "I want that guy in the men's movement… and to get him involved, we have to convince him that the masculinity he has learned is self-destructive and toxic, and that feminist change is in his interest".
[11] Messner argues that, at its core, feminism is in the best interest of every person because systemic, hegemonic oppression harms everyone, not just women.