Human behavior, including the wearing or shunning of masks, will determine the Covid-19 pandemic’s ultimate toll. To understand different behavioral choices a New England Journal of Medicine article looks at scientific mistrust and free-market principles, the polluted information environment, how beliefs shape our personal identity, the health fallout of economic devastation, and tribal norms. Also, an article on how the pandemic has changed our beauty habits in ways that can be better for skin, hair and nails.