Studies on the Basic Factors in Animal Fighting: VI. Inter-Species Coexistence in Birds

An attempt was made to investigate the hypothesis that type of abstract reasoning impairment was related to age. Forty brain damaged patients were divided into four age groups (30–39, 40–49, 50–59, and 60+) and evaluated by a concept identification task which yields data as to whether impairment is qualitative or quantitative. The results indicated that the greatest amount of qualitative type impairment occurred among the older brain damaged patients when compared with the other subjects.