The ONLY thing a person needs is Validation. You can interpret Maslow’s hierarchy as a need for validation. Validation that one deserves to be nourished physically and mentally.
Sometimes people are arrogant and seem like they don’t need any validation because they already think they are just too smart. If you want to get work done out of them, you need to continue to validate their impression of themselves. Is this morally and ethically acceptable? I’ll leave that up to you.
Similar topic has been visited and discussed about, a few months ago right on this blog. The post is “My constant nagging thought“