Assertive behavior in children is characterized as manipulation and exploration of the environment. Assertive behavior can be nondestructive or destructive. It has been suggested that learning is dependent on assertion and that distortion or inhibition of assertive behavior may restrict or distort the learning process. Fifty Head Start children were tested for the existence of assertive behavior by teacher and observer ratings, and that data was compared with the childrens' scores on the Stanford-Binet. An assertive behavior task, the Beller task, was also administered to the children. Comparison of the teacher and observer ratings resulted in a significantly high correlation. Both kinds of ratings were also correlated with the Beller task data, and the results indicated that the latter was a valid measure of assertion. Of the 35 items on the Binet, the "assertive" children scored better on 29 items than the less assertive children, with significant differences occurring on eight of the 29. Thus, assertive behavior and cognitive performance appeared to be positively related. (WD)