Stick It to the Man
Don’t send me e-mail about this, because yes, your dictionary might say that the distinction between the two words is hazy at best, but shades of meaning are important, and anti- words mean active opposition while a- words mean absence. If you’re confused, use antisocial, which has a more inclusive meaning. Killing a dude isn’t asocial, but most dictionaries will let you get away with saying that pretending not to see that guy you know on the train is antisocial.
Unless, of course, you’re writing about the eugenics movement, and then “asocial” means “someone who doesn’t fit eugenic ideals of contribution to the body politic” and can refer to people who prefer to remain celibate, anyone who’s not cisgendered and heterosexual, people who actually are antisocial, people who live on the margins of the economy, people with disabilities that make it difficult for them to work in an industrial capitalist context, women who’ve transgressed the sexual purity double standards, or people from minority culture and/or ethnic groups.
It took me such a long time to figure out how exactly introverts were a threat to the gene pool.