The Executive Must be Likable.

The most important book you can read to become a better executive is the Bible. Even for non-believers, the ancient wisdoms compiled in this book are too compelling to be ignored, and should be read and reread constantly. The second most important book you can read is “How to Win Friends and Influence People” by Dale Carnegie. The main purpose of this book is to develop habits that will allow you to become more likable.
For success as an executive, you must work to become more likable. People who aren’t likable will always level out and stall in their careers. Where this happens depends on the strength of their other attributes (i.e. intelligence, technical competence, ability to hold others accountable, etc.). But they will hit their limit eventually.
The reality is that people want to be around others who are likable. Likable people are pleasant, engaging, and make you feel good about yourself. Who wouldn’t want to be around someone like that?
By contrast, unlikeable people a make you feel worse having come into contact with them. They may be good at certain aspects of their job, but people try to avoid them to the extent possible. They are just draining.
So how does one become likable? The best advice I can give you to start immediately is to follow the Golden Rule. This is “treat others as you want to be treated”. While this quotation is widely attributed to Jesus from Matthew 7:12, C.S. Lewis points out in The Abolition of Man that a form of this phrase exists in every major religion and philosophy. It’s pretty important, and you’d better follow it if you want to become more likable.
Dale Carnegie goes further in “How to Win Friends and Influence People”. Here’s a summary of the advice he gives:

Fundamental Techniques for Handling People

1. Don’t criticize, condemn, or complain
2. Provide honest and sincere appreciation
3. The only way to influence someone is to talk in terms of what they want

Six Ways to Make People Like You

1. Become genuinely interested in other people
2. Smile
3. Remember their name and use it often
4. Be a good listener; encourage others to talk about themselves
5. Talk in terms of the other person’s interests
6. Make the other person feel important, and do it sincerely

How to Win People to Your Way of Thinking

1. The only way to win an argument is to avoid it
2. Show respect for the other person’s opinions; never say “You’re wrong”
3. If you are wrong, admit it quickly and emphatically
4. If you want to win someone over, first convince them that you’re their friend
5. Get the other person to say “yes” immediately
6. Let the other person do most of the talking
7. Let the other person feel that the idea is his or hers
8. See things from the other person’s point of view
9. Be sympathetic to their ideas and desires
10. People usually have two reasons for doing something: The one that sounds good and the real one; appeal to the nobler motive
11. Dramatize your ideas; make your presentation of information exciting
12. The way to get things done is to stimulate competition. Throw down a challenge to your team.

Be a Leader (How to Change People Without Giving Offense or Arousing Resentment)

1. Before finding fault, begin with praise and honest appreciation
2. Call attention to other people’s mistakes indirectly, by leading by example
3. Talk about your own mistakes before criticizing the other person
4. Ask questions instead of giving direct orders
5. Let the other person save face
6. Praise the slightest improvement and praise every improvement
7. Give the other person a good reputation to live up to
8. Use encouragement. Make the fault seem easy to correct
9. Make the other person happy about doing the thing you want them to do.