When it comes to compliments from their own sex, men often regard appearance-based praise as a come-on. In her 2003 book, Sociolinguistics: The Essential Readings, Christina Bratt Paulston writes that for heterosexual men, "to compliment another man on his hair, his clothes, or his body is an extremely face-threatening thing to do, both for the speaker and the hearer."

In the book The Psychology of Love, Michele Antoinette Paludi points out that stepping outside of gender roles can reduce attraction between partners.

"Current research indicates that gender-atypical qualities are often turn-offs in intimate relationships … Women also experienced social costs for atypical gender behavior … both men who were passive and women who were assertive were evaluated as significantly less socially attractive by men than women who did not engage in self-promoting behaviors."

Being the arbiter of someone's attractiveness can be interpreted as an expression of masculinity that women are not traditionally expected to adopt. Further, it is possible that a good portion of men don’t want to be essentially "treated like women," as their masculinity is dependent on being above the judgments women are often subjected to.

Men are also more reluctant to express behaviors such as envy, according to the 2012 book, Gender, Culture and Consumer Behavior, which suggests that men hesitate to display “low-agency” emotions such as anxiety, vulnerability and jealousy.

In life as well as in art, a man’s focus on his own appearance can be perceived as detracting from his perceived masculinity in the eyes of male reviewers. In her book, Extra-Ordinary Men: White Heterosexual Masculinity in Contemporary Popular Cinema, Nicola Rehling points out that in the movie Gladiator, Maximus had a muscular build but was not sexualized on-screen. In the movie Troy, meanwhile, Brad Pitt’s Achilles was practically groomed for the enjoyment of straight female and gay male viewers. Crowe's body was not nearly as exposed as Pitt's was throughout the movie.

Rehling writes, "In the majority of reviews of the film, Brad Pitt was compared unfavorably with Crowe, with many expressing disappointment that he failed to import the primal masculinity that was such a big box office attraction in Gladiator. The adulation of Crowe's Maximus would seem to articulate a desire for an undiluted, corporeal, physical male presence."

The consequences for women giving men compliments are also different than those for men giving women compliments. In a 2006 study from Williamette University's College of Liberal Arts, researchers Christopher Parisi and Peter Wogan found that college-aged men were generally given compliments on skills, while women were given compliments on their looks. Parisi and Wogan also found that women felt the need to be cautious when complimenting men on their appearance because they didn't want to be "too forward" or attract "unwanted attention."

That fear is supported by a 2008 study, conducted in Australia by Griffith University, which hypothesized that men are more likely to interpret or misinterpret female compliments as seductive or flirtatious than women are male compliments.

Who knew complimenting could be so complicated? Perhaps if we better understand the social norms behind compliments, women and men alike could begin to feel more comfortable praising each other in a non-sexual way, and to not expect anything in return.

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