Saying no to someone who asks for something is often easier said than done. Maybe it's a boss who wants you to take on a new assignment. Or your kid's teacher, seeking volunteers for a field trip. Or a friend who asks you to lend her money. How should we respond to these demands on our time, energy, and resources? This week, psychologist Vanessa Patrick explores why it's so hard to say no, and how we can set boundaries that will make it easier to do so.