David's portrait magic

What do you all think is David's secret to getting such genuine expressions from his subjects? Whether it's the stunning models like Anika and Catalina, or the LAPD officers, everyone just looks so natural and comfortable in front of his lens. I mean, he even got that dad and son in Venice to open up so beautifully. Is it his approach? His vibe? Anyone else notice how he always manages to capture that authentic spark? I'm curious to hear your theories!