Chantek also demonstrated self-awareness, by grooming himself in a mirror and by using signs in mental planning and deception. Rather than simply exhibiting conditioned responses, as critics of primate intellect contend, Chantek learned roles – and role reversals – in games like 'Simon Says'. Like many other orangutans who have demonstrated problem solving skills, Chantek exhibited certain intuitive and thinking character traits comparable to the rationality used in human engineering. His intellectual and linguistic abilities made some scientists, including Miles and Dawn Prince-Hughes, regard him as possessing personhood.