1) Simplicity, without condescension It's about using a simple vocabulary, yet explaining something new in a fascinating way. When you're in a TV interview, you're there to inform, not to impress. Communication is more important than demonstrating your vast expertise.
2) A genuine interest in the topic There's no doubt that David is an enthusiast for his subject. He'd hardly have pursued it so long if not. The important thing is to show that enthusiasm without appearing to be obsessive. He hits the mark perfectly. If you aren't enthusiastic about your topic, or at the very least interested in it, viewers will notice.
3) Humility One of the most endearing features about David is that he has retained both his sense of wonder and his humility. He never comes across as superior or all-knowing. He's clearly still learning, and is amazed by what he finds. It's a very important characteristic to remember, especially when being interviewed about a crisis. Always remain humble.
4) Planning None of the spectacular scenes in his documentaries just appear. They are filmed after long days of careful planning and patience. It's the same with interviews. You must plan, and you must be patient for your opportunity to make your point.
And if you haven't ever watched one of David Attenborough's programmes, I urge you to seek one out.
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