Variables that differentiate those who oppose the nuclear arms race were investigated. Thirty-eight employees of an industrial research facility were asked to respond to: 1) a demographic data form; 2) a measure of ego development; 3) a nuclear attitudes and information questionnaire; and 4) two imagery questions – one about the consequences of nuclear war and one about images of anger. Data were analyzed by dividing participants into three nuclear attitude groups – supporters of the status quo, fence sitters, and antinuclear protesters – and statistically comparing group responses. Results showed that protesters were better educated and more likely to be female. With fence sitters, they shared a tendency to be better informed about nuclear issues and with supporters, a belief that nuclear war is imminent. They displayed a trend toward greater production of concrete images of nuclear war – a finding that provides tentative validation for previous research. Finally, protesters did not obtain ego-development scores that differed significantly from the scores of the other two groups; they did, however, produce more vivid images of anger.