This study describes the differences between adult rheumatoid arthritics (RA's) and controls on a number of personality variables. The cases come both from a national interview sample and a university arthritis clinic, while the controls were part of a cluster which included the spouse of the RA, the RA's sib and his (her) spouse, a cousin of the RA, and an unrelated individual. The data were collected in the course of three structured interviews. The major findings were the following: 1. (1) RA's of both sexes score higher on several measures of poor mental health than the non-RA's. For the women, these differences are stronger and involve more diverse aspects of poor mental health. 2. (2) Women with RA report more frequent anger-irritation and more frequent impulses to overt aggression than women without RA. Involved in these differences are scales reflecting both general anger-aggression and that which is directed at the husband. 3. (3) Men with RA, compared with healthy men, report less frequent impulses to general overt aggression, less wife-directed aggression, stronger guilt about such aggression, and their anger episodes were of longer duration. 4. (4) When a difference score was computed between two scales, frequency of impulses to overt aggression and frequency of actual aggressive acts, women with RA, compared with healthy women, showed stronger control over the expression of such impulses, but seemed unable to apply the control to all types of aggressive impulses equally. 5. (5) Women with RA were unduly frequently found above median on 'guilt about spouse-directed aggression' and above median on several measures of husband directed anger-aggression. It was suggested that this might indicate greater conflict among the RA women. 6. (6) Comparing general and spouse-specific measures of overt aggression, (a) women with RA 'preferred' to direct their aggression at their husbands more than healthy women; while (b) men with RA 'avoided' directing their aggression at their wives more often than healthy men. 7. (7) When husbands' self-reports of wife-directed anger-aggression were correlated with wives' self-reports of husband-directed anger-aggression, the associations were positive and moderate to strong. 8. (8) Marriages of RA wives and healthy husbands were highest on mutually directed anger-aggression; marriages of RA husbands and healthy wives were the lowest, while the healthy husbands-healthy wives marriages were intermediate. © 1969.