A good book I often recommend is: Yes!: 50 Scientifically Proven Ways to Be Persuasive by Dr. Robert B. Cialdini et al. I first read the book when it came out in 2008. The book is designed for professionals who are interested in becoming better at understanding how to persuade or influence others. The book may also help you understand why you decide to do the things you do. Even if you are a researcher or teacher or a medical doctor, and so on, and not a business person, it's still important to understand how people are (or can be) influenced and persuaded by your words and behaviors. Each chapter focuses on a single question and is no more than 3-5 pages long. If you want to go deeper you can checkout the sources for each chapter in the Notes section.
"Yes!" is not a textbook, and it may not go deep enough for some, but for extremely busy professionals, this is a useful book with many clear, quick lessons that will get you thinking.
Above: The book on my desk. Each chapter focuses on a question such as what common mistake causes messages to self-destruct, how sticky notes can make your messages stick, etc. Checkout the table of contents here to see all 50 chapters at a glance.
If you want a little more depth, I suggest Cialdini's other huge bestsellers Influence: The Psychology of Persuasion and Influence: Science and Practice. These books have sold in the millions by now. Some people may be skeptical about the ethics of trying to persuade and influence others, but remember, it's not just about marketers trying to influence someone to buy something they do not need with money they do not have. Persuasion can be used for good just as it can be used for ignoble reasons. For example, a medical doctor often needs to be effective at persuading patients to comply with her recommendations. Facts, data, and argument are usually not enough to influence a change in behavior.
If you do not have enough time to read the Influence books yet, the 12-minute video below will give you a good idea as to the key findings in Cialdini's research. The video presentation covers the six universal principles of persuasion which are scientifically proven, according to the author, to make you more effective at influence and persuasion. (Watch below or on YouTube.)
Principles of Persuasion at a glance
In an ideal world people would use reliable information and sound logic to guide their thinking and decision making, but the reality is people use shortcuts or "rules of thumb" to make decisions. The six shortcuts below, according to the author, are universal rules of thumbs that guide human behavior. The key is to understand these shortcuts and use them in an ethical manner to persuade others. There are many examples in the books, but in the video they can only give one or two. Here are the six principles in brief.
(1) Reciprocity. The obligation to give back when you have previously received. The key takeaway: Be the first to give and make it personal and unexpected.
(2) Scarcity. People want more of those things which are perceived to be rare or in short supply. It's not enough to tell people about the benefits they will gain, you must also tell them what they stand to lose or miss out on if they do not adopt your idea (or buy your product, or choose your school, etc.).
(3) Authority. People will follow the lead of credible, knowledgeable experts. In the presentation space, it's highly desirable to have someone give a short and concise introduction of yourself which highlights why you are an expert worth listening to.
(4) Consistency. Asking for small commitments that can easily be made. Then going back and asking for larger commitments later. Sometimes this is called "getting a lot by first asking for a little." People want to be consistent, according to the principle, so if they said yes to you previously they are more likely to do it again.
(5) Liking. People prefer to say yes to the people they like. There are three factors in determining whether we like someone (a presenter on stage, for example). We tend to like people (1) who are similar to us, (2) who pay us compliments, and (3) who cooperate with us. For presenters it's important to really know your audience so that you can touch immediately on something shared and personal with the audience.
(6) Consensus. People often look to the actions of others to determine their own. So rather than simply hitting people over the head with your logic and data trying to persuade them to accept your idea, you can also elaborate on all the other people who have already accepted your proposal.