*One study used personality tests and careful observation to rate the subjects for age, status, bravery, curiosity, and the tendency to solve problems independently versus by observing and imitating others. The experimental subjects sought out others like them: the curious spent time with the curious, the brave with the brave, the young with the young, and the old with the old, while the high-status types strutted around together. The only unusual thing about this research? It was carried out not on humans but on baboons.