Fear of rising crime is changing the way Americans live, prompting them to buy weapons and dress plainly to avoid attracting the attention of muggers, according to a new study by a private research group. "Fear of crime is slowly paralyzing American society," the report warned, adding, "Although the facts about crime in America are shocking, society seems to have adapted to this new reality almost without being aware of how such an acommodation affects society's well-being." The survery, which covered more than 1,000 adults, was sponsored by ATO Inc., a diversified manufacturer of products ranging from sporting goods to fire apparatus. It was largely inspired, however, by David Finn, chairman of Ruder & Finn, whose brother Herbert, 60, was murdered during a street robbery in the Bronx last year. Among the findings: Four of every 10 Americans are afraid they will become victims of murder, rape, robbery or assault, and they feel unsafe in their environment. Eighty percent believe the prison system does not rehabilitate criminals; 66 percent support the death penalty for murderers, and 45 percent support sterilization for habitual sex offenders and the hopeless insane. Fifty-two percent said they owned guns, with Southerners, married people, men and blacks more likely than others to have guns. Those most intensely fearful of becoming victims are generally residents of large cities, the young, women, the highly educated and blacks, many of whom live in high crime areas. Sixty percent said they dress plainly to avoid drawing attention to themselves.