- Abstract 1. 1. The effects of inositol (20 g/day, oral) on spatial learning and spontaneous home-cage behavior of four Rhesus monkeys, were studied in a crossover design. 2. 2. Results indicate no marked inositol effect on learning, memory, or behavior. There was a suggestion of an effect of chronic inositol in reducing cage-induced repetitive behavior as indicated by increased switching between modes of behavior, and reduction in length of longest behavioral bout. Furthermore inositol may increase time spent in environmentally- rather than self-oriented behavior. 3. 3. Previous behavioral studies of inositol were performed in rats, which maintain low brain inositol levels compared to primates, including humans. The present study demonstrates the feasibility of primate behavioral studies with inositol, and shows the need for longer time experiments and increased variety of behavioral tests.