I'm a researcher who works in the area of population health and racism. I recently came across a paper outlining the ways in which peer attitudes influence individuals' expressed prejudices and acceptance of stereotyping. From the introduction:

Individuals often conform to the intergroup attitudes and behaviors modeled by their peers in a given situation. They express more tolerance of racist speech following a peer's expression of racist views, and less tolerance after a peer condemns racism (Blanchard, Crandall, Brigham, & Vaughn, 1994); they adjust to the current peer consensus on stereotyping when reporting their own racial stereotypes (Sechrist & Stangor, 2001; Stangor, Sechrist, & Jost, 2001); they are more tolerant of discrimination against minorities and women after overhearing racist or sexist jokes (Ford & Ferguson, 2004; LaFrance & Woodzicka, 1998) and when they perceive prejudice against those groups to be socially acceptable (Crandall, Eshleman, & O'Brien, 2002). A signal as subtle as a peer's antiracism t-shirt can go so far as to influence an individual's unconscious, uncensored prejudice (Lun, Sinclair, Glenn, & Whitchurch, 2007; Sinclair, Lowery, Hardin, & Colangelo, 2005). I thought I would forward it to you since it fits in so neatly with the idea that rape jokes facilitate acceptance of rape and so on.

Shaker Imagynne emails, which I am publishing with her permission:This is what I'm talking about when I say, over and over like the broken record that I am, whether it's about marginalizing humor, rape jokes, images and objects of disembodied women , " odd news ," advertising movies and other pop culture,, that it is the pervasive, ubiquitous, inescapable little stuff that creates the foundation of cultural prejudices on which the big stuff is dependent for its survival.Which is why the recommendation to "get over it," so often intertwined with accusations of looking for things about which to get offended, is not merely ill-advised and totally fucking obnoxious, but counter to the ultimate goal of social justice. We can't ignore "the little stuff," because that'sthe stuff,the fertile soil in which everything else takes root and from whence everything else springs,the way that the fundamental idea of inequality is conveyed over and over and over again.Asking me to "let it go" is thus asking me to participate in my own marginalization and/or the marginalization of others, and I can't do that. I won't. I'm all in.