A devout Presbyterian, DeJarnette supported the temperance movement. He believed that sterilizing people with certain traits that he believed to be hereditary would prevent these traits from being passed on to future generations. “To this class of the unfit belong the insane, the epileptic, the alcoholic, hereditary criminal, the syphilitic, the imbecile and the idiot, and none of these should reproduce,” DeJarnette wrote. “If proper steps be taken, the unfit can be made to grow annually smaller, and finally disappear entirely from our registers.”