It's about their experience and consciousness, which are emergent properties of intelligence. I don't think anyone's arguing that we should spare whales and dolphins simply on account of their raw IQ. Personhood, or near-personhood, is a concept applied to beings that understand who they are in relation to the world and are capable of experiencing the world the way a person does. - Probably all living beings understand who they are in relation to the world. Everything from micro organisms to huge whales. You pointed out that there is a movement to protect their rights, but the Swiss are also legally protecting plants (because plants are conscious according to science as well). - Other life forms (including whales) do not experience the world in the way a person does, because THEY ARE NOT PEOPLE. - Since you already pointed out that IQ is not a factor, there is nothing to back up your claim that whales should be protected over other life forms (as all life forms are conscious, understand who they are in relation to the world, and are not people).