they can't shrug

Tom Wolfe thinks speech is entirely different from 'other survival benefits'.

'Only with speech can you ask the question, "Why?" Animals cannot ask why. In one way or another, they can ask what, where, and when. But they cannot ask why. I've never seen an animal shrug. When you shrug, you're trying to say, "I don't know why." And they also can't ask how.'

He discusses language, status and the unfathomable complexities of the brain with the cognitive neuroscientist Michael Gazzaniga. (HT: BIB.)