THE INTERPERSONAL THEORY OF DANGEROUSNESS HOLDS THAT DANGEROUSNESS IS A FUNCTION OF PERCEPTIONS AND ATTRIBUTIONS WITHIN AN INTERPERSONAL CONTEXT RATHER THAN A STABLE PERSONALITY TRAIT. IT WAS HYPOTHESIZED THAT BLACK INMATES ARE PERCEIVED BY GUARDS AS BEING MORE DANGEROUS THAN WHITE INMATES, AND THAT THIS PERCEPTION IS DUE TO THE GUARDS' OWN FEARS AND BIASES RATHER THAN TO ANY GREATER DEGREE OF DANGEROUS BEHAVIOR ON THE PART OF BLACKS. THREE 5-POINT SCALES OF AGGRESSION WERE COMPLETED BY 54 WHITE AND 24 BLACK MALE INMATES OF A STATE PRISON. GUARDS WHO KNEW THE INMATES RATED THEM ON THREE ANALOGOUS SCALES. BLACKS DID NOT SEE THEMSELVES AS MORE AGGRESSIVE THAN WHITES, BUT GUARDS RATED BLACKS AS MORE AGGRESSIVE. THE GUARDS TRANSLATED THEIR RATINGS OF AGGRESSIVENESS INTO ACTION: BLACKS HAD SUBSTANTIALLY MORE RULE INFRACTIONS ON THEIR RECORDS THAN DID WHITES. HOWEVER, THE INFRACTIONS FOR WHICH BLACKS WERE DISPROPORTIONATELY REPRESENTED WERE THOSE INVOLVING THE MOST PERSONAL DISCRETION ON THE PART OF GUARDS. THE FINDINGS SUPPORT AN INTERPERSONAL THEORY OF DANGEROUSNESS. THEY ALSO CARRY IMPLICATIONS FOR BAIL, SENTENCING, INCARCERATION, AND RELEASE DECISIONMAKING; THE SELECTION AND TRAINING OF CORRECTIONAL OFFICERS TO COMBAT RACIAL BIAS; AND THE STRUCTURING OF PRISON RULES. TABULAR DATA AND A LIST OF REFERENCES ARE INCLUDED.