Many psychologists and experts in human behavior believe that a person’s emotional intelligence quotient (EQ) may be more important to success than the person’s intelligence quotient (IQ).

There are many valid definitions of emotional intelligence. We like to think about it as the four quadrants of a two-by-two matrix. On one axis, we have “Self” and “Others.” On the other axis, we have “Understand” and “Influence.” We’ll consider each quadrant below.

1. Understand yourself

Aristotle said that self-knowledge is the beginning of wisdom. It’s true. You have to begin by understanding what is going on in your own head. Do you understand what is driving your emotions? If you are upset, blue, angry or happy, do you know why?

This may sound easy, but for many, it’s not. To change your world, you have to begin by understanding why you are feeling the way you’re feeling -- you have to understand yourself.

Related: Why Being a Self-Aware Leader Is Not Enough

2. Influence yourself

This is your ability to modify your own behavior, as appropriate. It’s your ability to be a self-starter. Are you intrinsically motivated or do you require extrinsic motivation? Successful people are able to set personal goals, map out a plan to achieve their goals and implement the plan -- they are able to influence their own behavior positively.

3. Understand others

Understanding others is all about empathy -- your ability to comprehend what others are feeling and why and to know how your words and actions will be received by those around you. Without empathy, you’ll alienate people and never know why. It is very difficult to succeed without understanding others.

4. Influence others

This is your ability to motivate people effectively. Your success and effectiveness will be directly related to your ability to get people to do what you want them to do. This isn’t manipulation. Manipulation is influencing others in a way that benefits you, but may be bad for them. Motivating others always creates a win-win. Successful people are able to influence others in a way that benefits everyone.

Related: 7 Essentials for Overcoming Mental Barriers to Exceptional Success

Does emotional intelligence explain success in business? We would argue that success in business is a function of four things: Your IQ (how smart you are), your prior experience (including your education, work experience and training), the level of effort you put forth and your emotional intelligence (as defined above).

Most organizations are quite good at assessing the first three. They can assess a person’s IQ by looking at the schools they went to, academic performance, standardized test scores, etc. In fact, prospective employers can administer a pre-employment test to determine cognitive capability in an area relevant to the job, and some do. Resumes lay out a prospective employee’s prior experience. Employers use prior accomplishments and reference checks to determine the level of effort that an employee is likely to exert.

Although companies often do a good job of assessing the first three elements, rarely do they effectively assess emotional intelligence. It is not surprising that the one element of success for which companies do not effectively screen is the one that differentiates performance.

Job candidates have to be strong on the other three dimensions to receive an offer. However, emotional intelligence is most often not measured effectively. Therefore, candidates may be weak on this dimension and still get the job. Unfortunately, this weakness will likely prevent success.

Although many ignore it, emotional intelligence is critical to a person’s success in business. The good news is that it can be measured and it can be improved.

Related: 7 Interview Questions That Determine Emotional Intelligence