I disagree with this. People tend to ignore large portions of their environment because they are, for their current purposes, irrelevant. In other cases, it is certainly possible for an individual to find some section of its perceptual world sufficiently significant to develop its own conceptul scheme regarding it. This is what we might call an invention or discovery. It happens more rarely than you might think.
People start with a broad sensory range and narrow that range as they learn.
Seldom does that range increase. We presuppose a culture, a social context. But it could have been otherwise and we might still be able to recognize cognition in a world in which people developed communication differently. This is a nonsequitur. What we have is neutral evidence and two theories which explain it.